Cross-chain transaction method, cross-chain system construction method and related device

Abstract

A cross-chain transaction method, applied to a cross-chain system, the cross-chain system comprising a first blockchain network and a heterogeneous second sub-blockchain network and third blockchain network. The method comprises: a cross-chain component of the first blockchain network acquiring a cross-chain transaction request, the cross-chain transaction request being used to request execution of a cross-chain transaction from a second blockchain network to the third blockchain network, the cross-chain component performing identity authentication and permission verification based the cross-chain transaction request, and obtaining a verification result; when the verification result indicates that verification is successful, and when nodes of the first blockchain network reach a consensus on the cross-chain transaction, the cross-chain component recording transaction information of the cross-chain transaction in a ledger of the first blockchain network, and the cross-chain component of the first blockchain network then notifying a cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction to a ledger of the third blockchain network. The method does not rely on a third party, and solves the problem of relying on the endorsement of a trusted third party or requiring a third-party relay chain to achieve cross-chain capabilities.

Description

A cross-chain transaction method, a cross-chain system construction method, and related equipment

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on December 30, 2023, with application number 202311861705.8 and invention name “A cross-chain transaction method, cross-chain system construction method and related equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of blockchain technology, and in particular to a cross-chain transaction method, a cross-chain system construction method, a cross-chain system, a cross-chain management system, a computing device cluster, a computer-readable storage medium, and a computer program product. Background Art

[0003] A blockchain network is a peer-to-peer network system that uses cryptography and consensus mechanisms to build and store massive chains of transaction data. Currently, there are thousands of publicly available blockchain networks, but these networks vary in security and privacy, transaction throughput, and scalability. This has led to disconnections between blockchain networks, creating data and value silos. The inter-chain barriers and trust gaps created by these silos have significantly constrained the large-scale development of blockchain applications and hindered interoperability and liquidity within the blockchain ecosystem.

[0004] Blockchains with different architectures rely on different consensus algorithms, data structures, security algorithms, and ledger types, resulting in interoperability between blockchains. To address this, the industry has proposed cross-chain technology to facilitate the flow of value and transaction interaction between blockchain ecosystems, thereby maximizing the application value across blockchain networks.

[0005] Currently, related cross-chain technologies rely on the endorsement of a trusted third party, or require a third-party relay chain to achieve cross-chain capabilities, resulting in transactions being restricted by third parties and making it difficult to meet business needs.

[0006] Summary of the Invention

[0007] This application provides a cross-chain transaction method and a cross-chain system construction method. This method improves the component model of heterogeneous chain cross-chain to construct a layer of node network based on any heterogeneous chain. By using the relay chain mode, efficient data synchronization between heterogeneous blockchain networks is achieved. This method uses cross-chain components on the node and does not rely on third parties. It solves the problem that related cross-chain technologies rely on the endorsement of trusted third parties or require third-party relay chains to achieve cross-chain capabilities. It can meet business needs, especially the needs of transaction performance and transaction security. This application also provides a cross-chain system, cross-chain management system, computing device cluster, computer-readable storage medium and computer program product corresponding to the above method.

[0008] In a first aspect, the present application provides a cross-chain transaction method. The method is applied to a cross-chain system, wherein the cross-chain system includes a first blockchain network, a second sub-blockchain network, and a third blockchain network, wherein the second blockchain network and the third blockchain network are heterogeneous blockchain networks, and the first blockchain network, the second blockchain network, and the third blockchain network respectively deploy cross-chain components.

[0009] Specifically, the cross-chain component of the first blockchain network can obtain a cross-chain transaction request, which is used to request the execution of a cross-chain transaction from the second blockchain network to the third blockchain network. The cross-chain component of the first blockchain network then performs identity authentication and permission verification based on the cross-chain transaction request, obtaining a verification result. If the verification result indicates that the verification is successful, the cross-chain component of the first blockchain network can record the transaction information of the cross-chain transaction in the ledger of the first blockchain network when the nodes of the first blockchain network reach consensus on the cross-chain transaction. The cross-chain component of the first blockchain network then notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0010] In this method, the cross-chain component of a blockchain network is deployed within the blockchain network and can interact directly with nodes within that blockchain network. Furthermore, cross-chain components of different blockchain networks can interact through inter-component protocols, thus enabling interaction between different blockchain networks. When a cross-chain transaction occurs, cross-chain messages such as cross-chain transaction requests are intercepted by the cross-chain component of the blockchain network where the transaction initiator resides (e.g., the second blockchain network). These messages can then be forwarded to the first blockchain network through inter-component communication. The nodes of the first blockchain network reach a consensus on the cross-chain transaction, and the cross-chain component of the first blockchain network can record the transaction information in the first blockchain's ledger. The cross-chain component of the first blockchain network then, through inter-component communication, notifies the cross-chain component of the third blockchain network to record the cross-chain transaction information in the third blockchain network's ledger. This method improves the component model of heterogeneous cross-chain chains to construct a layer of node network based on any heterogeneous chain. Specifically, this cross-chain node network based on the cross-chain component, also known as a cross-chain component network, uses the relay chain paradigm to achieve efficient data synchronization between heterogeneous blockchain networks.

[0011] In some possible implementations, the cross-chain component of the first blockchain network, the second blockchain network component, and the third blockchain network component form a synchronous network. Accordingly, the cross-chain component of the first blockchain network broadcasts a notification message via the synchronous network, which notifies the cross-chain component of the third blockchain network to record transaction information of the cross-chain transaction in the third blockchain network's ledger.

[0012] This method ensures the reachability of messages by synchronizing the network, ensuring that the cross-chain component of the first blockchain network can notify the cross-chain component of the third blockchain network to perform cross-chain transaction record operations, thereby achieving data consistency between multiple chains.

[0013] In some possible implementations, cross-chain components in the synchronization network synchronize messages using a rumor protocol. This allows for rapid message dissemination, allowing cross-chain components in the third blockchain network to be notified as quickly as possible to record cross-chain transactions, improving synchronization efficiency.

[0014] In some possible implementations, a direct channel is established between the cross-chain component of the first blockchain network and the cross-chain component of the third blockchain network. Accordingly, the cross-chain component of the first blockchain network can notify the cross-chain component of the third blockchain network via the direct channel to record the transaction information of the cross-chain transaction in the third blockchain network's ledger.

[0015] This method can further improve synchronization efficiency by notifying the cross-chain component of the third blockchain network through a direct channel to record the transaction information of the cross-chain transaction in the third blockchain network's ledger. In particular, in continuous cross-chain transaction scenarios, subsequent cross-chain transactions can leverage the links established by previous transactions, significantly improving synchronization efficiency, such as the efficiency of synchronizing cross-chain transactions.

[0016] In some possible implementations, the cross-chain component of the first blockchain network identifies the transaction type of a cross-chain transaction. Accordingly, when the transaction type is a cross-chain write, the cross-chain component of the first blockchain network records the transaction information of the cross-chain transaction in the ledger of the first blockchain network. This method distinguishes between different transaction types and, for cross-chain writes, allows the first blockchain to record the transaction information of the cross-chain transaction in its ledger, thereby achieving data consistency across different chains.

[0017] In some possible implementations, upon successful recording of a cross-chain transaction in the third blockchain network's ledger, the cross-chain component of the third blockchain network notifies the cross-chain component of the second blockchain network to record the cross-chain transaction in its ledger. This allows the second blockchain network to record the transaction information in its ledger based on the execution status of the cross-chain transaction on the third blockchain network, improving synchronization efficiency while ensuring atomicity.

[0018] In some possible implementations, the cross-chain component of the first blockchain network can receive the chain information and cross-chain access permission information of the second blockchain network and the chain information and cross-chain access permission information of the third blockchain network, and record the chain information and cross-chain access permission information of the second blockchain network and the chain information and cross-chain access permission information of the third blockchain network in the ledger of the first blockchain network.

[0019] This method records the registered chain information and cross-chain access permission information to the ledger of the first blockchain network, and can be used to audit or query the status (valid or invalid, or whether it has lost activity) or permission information of nodes (such as cross-chain nodes) in the registered blockchain network.

[0020] In some possible implementations, the cross-chain component of the first blockchain network detects the validity of the third blockchain network based on the chain information of the third blockchain network. If the third blockchain network is valid, the cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0021] In this method, the cross-chain component of the first blockchain network first detects the validity of the third blockchain network, and then notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction, thereby reducing the risk of cross-chain transaction failure.

[0022] In some possible implementations, a cross-chain component on a first blockchain network receives a cross-chain transaction request routed by a cross-chain component on a second blockchain network based on a routing address. This allows the cross-chain component to transfer cross-chain transaction requests between different blockchain networks, laying the foundation for cross-chain transactions.

[0023] In some possible implementations, the cross-chain component includes a proxy and a controller (e.g., a cross-chain controller). The proxy encapsulates the interaction interface of the heterogeneous blockchain network based on a universal interaction protocol. Accordingly, the cross-chain component of the second blockchain network monitors the cross-chain transaction request using the universal interaction protocol. This can shield the differences between different heterogeneous chains and support monitoring of heterogeneous chains.

[0024] In a second aspect, the present application provides a cross-chain system construction method. This method is applied to a cross-chain management system, wherein the cross-chain management system is used to construct a cross-chain system, wherein the cross-chain system includes a first blockchain network, a second sub-blockchain network, and a third sub-blockchain network, wherein the second blockchain network and the third blockchain network are heterogeneous blockchain networks, and wherein the method includes:

[0025] Deploy a cross-chain component on at least one node of the first blockchain network, deploy the cross-chain component on at least one node of the second blockchain network, and deploy the cross-chain component on at least one node of the third blockchain network;

[0026] The chain information and cross-chain access permission information of the second blockchain network are registered in the first blockchain network, and the chain information and cross-chain access permission information of the third blockchain network are registered in the first blockchain network. The chain information of the second blockchain network is used by the cross-chain component of the third blockchain network to discover the second blockchain network, and the chain information of the third blockchain network is used by the cross-chain component of the second blockchain network to discover the third blockchain network.

[0027] This method deploys cross-chain components on at least one node in a blockchain network to build or enhance the node's cross-chain capabilities, forming a cross-chain node. Through a registration and discovery mechanism, these components can be constructed into a synchronized network layered on top of any heterogeneous blockchain network. This synchronized network utilizes a relay chain model to achieve efficient data synchronization across heterogeneous blockchain networks. This method utilizes cross-chain components on the node, eliminating third-party reliance. This addresses the issue of related cross-chain technologies relying on trusted third-party endorsements or requiring third-party relay chains to achieve cross-chain capabilities, and can meet business needs, particularly those for transaction performance and security.

[0028] In some possible implementations, deploying the cross-chain component on at least one node of the third blockchain network includes:

[0029] Downloading the cross-chain component from the first blockchain network;

[0030] Adapting the cross-chain component to the third blockchain network;

[0031] Deploy the adapted cross-chain component on at least one node of the third blockchain network.

[0032] In some possible implementations, the method further includes:

[0033] Checking the status of a cross-chain component deployed by at least one node in the first blockchain network;

[0034] The availability of the first blockchain network is determined based on the number of nodes whose cross-chain component is in a normal state.

[0035] In some possible implementations, the method further includes:

[0036] The first blockchain network is configured as a main chain, and the main chain is used to relay cross-chain transactions between the second blockchain network and the third blockchain network.

[0037] In some possible implementations, the method further includes:

[0038] The second blockchain network is created using the first blockchain service, and the third blockchain network is created using the second blockchain service, wherein the second blockchain network and the third blockchain network are heterogeneous blockchain networks.

[0039] In some possible implementations, the first blockchain service and the second blockchain service provide a standardized interface, and creating the second blockchain network using the first blockchain service and creating the second blockchain network using the second blockchain service include:

[0040] The first blockchain service is called through the standardized interface to create the second blockchain network, and the second blockchain service is called through the standardized interface to create the third blockchain network.

[0041] In some possible implementations, creating the second blockchain network using the first blockchain service includes:

[0042] The second blockchain network is created using the first blockchain service, independent of the organization of the first blockchain network.

[0043] In a third aspect, the present application provides a cross-chain system. The cross-chain system includes a first blockchain network, a second sub-blockchain network, and a third blockchain network, wherein the second blockchain network and the third blockchain network are heterogeneous blockchain networks, and the first blockchain network, the second blockchain network, and the third blockchain network respectively deploy cross-chain components;

[0044] The cross-chain component of the first blockchain network is configured to obtain a cross-chain transaction request, the cross-chain transaction request being used to request execution of a cross-chain transaction from the second blockchain network to the third blockchain network, perform identity authentication and permission verification based on the cross-chain transaction request, and obtain a verification result;

[0045] The cross-chain component of the first blockchain network is further configured to, when the verification result indicates that the verification is passed and the nodes of the first blockchain network reach a consensus on the cross-chain transaction, record the transaction information of the cross-chain transaction in the ledger of the first blockchain network, and notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0046] In some possible implementations, the cross-chain component of the first blockchain network, the second blockchain network component, and the third blockchain network component form a synchronous network, and the cross-chain component of the first blockchain network is specifically configured to:

[0047] A notification message is broadcast through the synchronization network, where the notification message is used to notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0048] In some possible implementations, the cross-chain components in the synchronization network synchronize messages through a rumor protocol.

[0049] In some possible implementations, a direct channel is established between the cross-chain component of the first blockchain network and the cross-chain component of the third blockchain network;

[0050] The cross-chain component of the first blockchain network is specifically used to:

[0051] Notify the cross-chain component of the third blockchain network through the direct channel to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0052] In some possible implementations, the cross-chain component of the first blockchain network is further configured to:

[0053] The cross-chain component of the first blockchain network identifies the transaction type of the cross-chain transaction;

[0054] The cross-chain component of the first blockchain network is specifically used to:

[0055] When the transaction type is cross-chain write, the transaction information of the cross-chain transaction is recorded in the ledger of the first blockchain network.

[0056] In some possible implementations, the cross-chain component of the third blockchain network is specifically used to:

[0057] When the transaction information of the cross-chain transaction is successfully recorded in the ledger of the third blockchain network, the cross-chain component of the second blockchain network is notified to record the transaction information of the cross-chain transaction in the ledger of the second blockchain network.

[0058] In some possible implementations, the cross-chain component of the first blockchain network is further configured to:

[0059] Receive the chain information and cross-chain access permission information of the second blockchain network and the chain information and the cross-chain access permission information of the third blockchain network, and record the chain information and cross-chain access permission information of the second blockchain network and the chain information and the cross-chain access permission information of the third blockchain network in the ledger of the first blockchain network.

[0060] In some possible implementations, the cross-chain component of the first blockchain network is further configured to:

[0061] Detecting the validity of the third blockchain network based on the chain information of the third blockchain network;

[0062] The cross-chain component of the first blockchain network is specifically used to:

[0063] When the third blockchain network is valid, the cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0064] In some possible implementations, the cross-chain component of the first blockchain network is specifically used to:

[0065] Receive a cross-chain transaction request routed by the cross-chain component of the second blockchain network according to the routing address.

[0066] In some possible implementations, the cross-chain component includes an agent and a controller, wherein the agent encapsulates the interaction interface of the heterogeneous blockchain network based on a universal interaction protocol;

[0067] The cross-chain component of the second blockchain network is used to:

[0068] The cross-chain transaction request is monitored through the universal interaction protocol.

[0069] In a fourth aspect, the present application provides a cross-chain management system. The cross-chain management system is used to build a cross-chain system, the cross-chain system including a first blockchain network, a second sub-blockchain network, and a third sub-blockchain network, the second blockchain network and the third blockchain network being heterogeneous blockchain networks, and the cross-chain management system includes:

[0070] A deployment module, configured to deploy a cross-chain component on at least one node of the first blockchain network, deploy the cross-chain component on at least one node of the second blockchain network, and deploy the cross-chain component on at least one node of the third blockchain network;

[0071] A registration module is used to register the chain information and cross-chain access permission information of the second blockchain network in the first blockchain network, and to register the chain information and cross-chain access permission information of the third blockchain network in the first blockchain network. The chain information of the second blockchain network is used by the cross-chain component of the third blockchain network to discover the second blockchain network, and the chain information of the third blockchain network is used by the cross-chain component of the second blockchain network to discover the third blockchain network.

[0072] In some possible implementations, the deployment module is specifically configured to:

[0073] Downloading the cross-chain component from the first blockchain network;

[0074] Adapting the cross-chain component to the third blockchain network;

[0075] Deploy the adapted cross-chain component on at least one node of the third blockchain network.

[0076] In some possible implementations, the system further includes:

[0077] A status management module is configured to check the status of a cross-chain component deployed on at least one node in the first blockchain network, and determine the availability of the first blockchain network based on the number of nodes where the cross-chain component is in a normal state.

[0078] In some possible implementations, the system further includes:

[0079] A configuration module is used to configure the first blockchain network as a main chain, and the main chain is used to relay cross-chain transactions between the second blockchain network and the third blockchain network.

[0080] In some possible implementations, the system further includes:

[0081] A creation module is used to create the second blockchain network using the first blockchain service, and to create the third blockchain network using the second blockchain service, wherein the second blockchain network and the third blockchain network are heterogeneous blockchain networks.

[0082] In some possible implementations, the first blockchain service and the second blockchain service provide standardized interfaces, and the creation module is specifically configured to:

[0083] The first blockchain service is called through the standardized interface to create the second blockchain network, and the second blockchain service is called through the standardized interface to create the third blockchain network.

[0084] In some possible implementations, the creation module is specifically configured to:

[0085] The second blockchain network is created using the first blockchain service, independent of the organization of the first blockchain network.

[0086] In a fifth aspect, the present application provides a computing device cluster. The computing device cluster includes at least one computing device, wherein the at least one computing device includes at least one processor and at least one memory. The at least one processor and the at least one memory communicate with each other. The at least one processor is configured to execute instructions stored in the at least one memory, so that the computing device or computing device cluster performs the method described in any implementation of the first or second aspect.

[0087] In a sixth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores instructions, wherein the instructions instruct a computing device or a computing device cluster to execute the method described in any implementation of the first or second aspect above.

[0088] In a seventh aspect, the present application provides a computer program product comprising instructions, which, when executed on a computing device or a computing device cluster, enables the computing device or the computing device cluster to execute the method described in any one of the implementations of the first or second aspect above.

[0089] Based on the implementation methods provided in the above aspects, this application can also be further combined to provide more implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] In order to more clearly illustrate the technical methods of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments.

[0091] FIG1 is an example diagram of a system architecture in a smart city scenario provided by this application;

[0092] FIG2 is a schematic diagram of deploying cross-chain components on nodes to build a cross-chain node network provided by this application;

[0093] FIG3 is a network diagram of a cross-chain system provided by this application;

[0094] FIG4 is a schematic diagram of a general architecture of a cross-chain system provided by this application;

[0095] FIG5 is a schematic diagram of the architecture of a cross-chain system provided by this application;

[0096] Figure 6 is a flow chart of a cross-chain transaction method provided by this application;

[0097] Figure 7 is a flow chart of a cross-chain system construction method provided by this application;

[0098] FIG8 is a schematic diagram of an application scenario of a cross-chain system construction and cross-chain transactions based on the cross-chain system provided by the present application;

[0099] FIG9 is a schematic diagram of the structure of a cross-chain management system provided by this application;

[0100] FIG10 is a schematic diagram of the structure of a computing device provided by the present application;

[0101] FIG11 is a schematic diagram of the structure of a computing device provided by the present application;

[0102] FIG12 is a schematic diagram of the structure of a computing device cluster provided by this application;

[0103] FIG13 is a schematic diagram of the structure of a computing device cluster provided by the present application;

[0104] FIG14 is a schematic diagram of the structure of a computing device cluster provided by this application;

[0105] FIG15 is a schematic diagram of the structure of a computing device cluster provided in this application. DETAILED DESCRIPTION

[0106] The terms "first" and "second" in the embodiments of this application are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0107] First, some technical terms involved in the embodiments of this application are introduced.

[0108] A blockchain network, also referred to as a blockchain, refers to a peer-to-peer (P2P) network built on blockchain technology. A blockchain network includes multiple blockchain nodes, each of which is a peer node (for ease of description, this application may also refer to blockchain nodes as nodes). In a blockchain network, multiple blockchain nodes jointly maintain a continuously growing blockchain ledger constructed from ordered data blocks. Each blockchain node stores a copy of the blockchain ledger and maintains consistency between the copies. Therefore, the blockchain ledger is the public ledger of the blockchain network. This public ledger is a distributed ledger, so the blockchain network can essentially be considered a distributed ledger system.

[0109] A distributed ledger system is a special type of distributed database system that only performs append operations and is suitable for use in untrusted environments. Specifically, in a distributed ledger system, new data can be appended to each node's local copy through transactions. A certain encryption mechanism is used to ensure that the data in the ledger cannot be arbitrarily deleted or altered. It is important to note that distributed ledger systems tolerate Byzantine faults, including but not limited to those caused by node crashes, inaccessibility, network latency, or malicious node behavior. Byzantine faults, also known as the Byzantine problem, refer to the problem of reaching consensus in scenarios where a small number of nodes may act maliciously (messages may be forged). To achieve data consistency across all nodes in a distributed ledger system, each system utilizes a consensus mechanism.

[0110] Consensus is an algorithm used by different nodes in a distributed ledger system to agree on the current valid state of the ledger. Due to the trade-offs between consensus, security, and consistency in distributed systems, consensus can be achieved either through eventual consistency or probabilistic eventual consistency. If all nodes successfully finalize a block and store the same copy of the ledger, the distributed ledger system has achieved eventual consistency.

[0111] Based on permissions, blockchain networks can be categorized as public and consortium. In some cases, these can be further divided into public, consortium, and private chains. In public chains, anyone can join the distributed ledger system and have read and write access to the distributed ledger. In contrast, the distributed ledger design of consortium chains excludes nodes from operations (such as transaction validation and joining the distributed ledger). Instead, operations such as joining and accessing the distributed ledger are performed using a permission or permission model. To enhance usability and performance in consortium chains, trade-offs are made between the characteristics of distributed systems. This means that the permission model strongly influences the applicability of the consensus mechanism. For example, public chain designs primarily employ consensus mechanisms that achieve only probabilistic eventual consistency, while most consortium chain designs require full eventual consistency, resulting in only a limited number of nodes being included in consensus discovery.

[0112] Distributed ledgers are designed to support the deployment and execution of custom programs (such as software programs, often referred to as "software" or "programs"), known as smart contracts. Smart contracts allow transactions to be triggered by defining standardized expressions within program code. Smart contracts can not only unlock assets stored on the distributed ledger (for example, using hash locks, time locks, and multi-signatures), but also store assets and trigger transactions once the conditions specified in the smart contract are met. These conditions can be related to data stored in the unified distributed ledger as well as external data (such as off-chain data).

[0113] Different distributed ledgers (e.g., heterogeneous distributed ledgers) can communicate through smart contracts, enabling operations between them (e.g., interoperability between distributed ledgers). Interoperability between different distributed ledgers is referred to as cross-chain. For a blockchain network (distributed ledger system), cross-chain capabilities include the ability to retrieve data from or exchange data with external systems. Cross-chain systems facilitate interoperability by enabling data exchange between different distributed ledgers and external systems. Data exchange with external systems can increase the flexibility of distributed ledgers, overcome performance issues caused by inherent limitations, and enhance the security of distributed ledgers.

[0114] Cross-chain systems can be implemented through notary mechanisms or third-party relay chains. The notary mechanism is a simple cross-chain mechanism widely used in digital currency exchanges. In essence, the notary mechanism is an intermediary method. Assuming that blockchains A and B cannot directly interoperate, a mutually trusted third party can be introduced as an intermediary to verify and forward cross-chain transactions. The relay chain, also known as a relay, aims to construct a third-party public chain that connects other chains in the blockchain network through a cross-chain messaging protocol. In specific implementation, a channel can be added between the two blockchain networks. A specific data structure is created within the channel, allowing the two chains to exchange cross-chain data through the data structure within the channel. This newly added channel is called the relay chain.

[0115] Notaries act as transaction confirmers and conflict arbitrators during transactions, replacing technical credit guarantees with centralized institutions. While this model offers fast transaction processing, strong compatibility, and a simple technical architecture, the security of central nodes has become a key bottleneck to system stability. The relay chain, a combination of sidechains and notary mechanisms, can be considered a decentralized notary mechanism. Currently, many cross-chain projects utilize a multi-chain architecture based on the relay chain. However, cross-chain interactions within this multi-chain architecture rely on the security of the relay component.

[0116] To address the problem that cross-chain technology relies on the endorsement of a trusted third party or requires a third-party relay chain to achieve cross-chain capabilities, resulting in transactions being subject to third-party constraints and making it difficult to meet business needs, this application provides a cross-chain transaction method. This method can be executed by a cross-chain system. The cross-chain system of this application includes a first blockchain network, a second sub-blockchain network, and a third blockchain network. The second and third blockchain networks are heterogeneous blockchain networks, and cross-chain components are deployed in each of the first, second, and third blockchain networks. The cross-chain components are used to provide cross-chain capabilities to nodes in the blockchain network, forming cross-chain nodes and enabling cross-chain transactions. The cross-chain components can be software, for example, software that encapsulates the methods and data required for cross-chain transactions. The cross-chain software is deployed on the blockchain network, which runs the cross-chain software to execute the cross-chain transaction method. In some examples, the cross-chain components can also be hardware that can execute the cross-chain transaction method when running. It should be noted that when executing the cross-chain transaction method, the cross-chain components deployed on different blockchain networks collaborate to complete the cross-chain transaction method.

[0117] Specifically, the cross-chain component of the first blockchain network can obtain a cross-chain transaction request, which is used to request the execution of a cross-chain transaction from the second blockchain network to the third blockchain network. The cross-chain component of the first blockchain network then performs identity verification and permission verification based on the cross-chain transaction request, obtaining a verification result. When the verification result indicates that the verification is successful, the cross-chain component of the first blockchain network can record the transaction information of the cross-chain transaction in the ledger of the first blockchain network, specifically a distributed ledger, when the nodes of the first blockchain network reach consensus on the cross-chain transaction. The cross-chain component of the first blockchain network then notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0118] In this method, the cross-chain component of a blockchain network is deployed within the blockchain network and can interact directly with nodes within that blockchain network. Furthermore, cross-chain components of different blockchain networks can interact through inter-component protocols, thus enabling interaction between different blockchain networks. When a cross-chain transaction occurs, cross-chain messages such as cross-chain transaction requests are intercepted by the cross-chain component of the blockchain network where the transaction initiator resides (e.g., the second blockchain network). These messages can then be forwarded to the first blockchain network through inter-component communication. The nodes of the first blockchain network reach a consensus on the cross-chain transaction, and the cross-chain component of the first blockchain network can record the transaction information in the first blockchain's ledger. The cross-chain component of the first blockchain network then, through inter-component communication, notifies the cross-chain component of the third blockchain network to record the cross-chain transaction information in the third blockchain network's ledger. This method improves the component model of heterogeneous cross-chain chains to construct a layer of node network based on any heterogeneous chain. Specifically, this cross-chain node network based on the cross-chain component, also known as a cross-chain component network, uses the relay chain paradigm to achieve efficient data synchronization between heterogeneous blockchain networks.

[0119] Communication between cross-chain components can be based on permissions and peer-to-peer encryption to ensure the security of cross-chain transactions. It should be noted that this method uses cross-chain components on nodes and does not rely on third parties. This solves the problem of related cross-chain technologies relying on the endorsement of trusted third parties or requiring third-party relay chains to achieve cross-chain capabilities. It can meet business needs, especially those for transaction performance and security.

[0120] This application can be applied to scenarios where data interaction between multiple chains is required within blockchain (e.g., consortium blockchains and public blockchains). This data interaction can include cross-chain transactions, which require multi-chain data consistency processing to achieve data consistency across multiple chains. For example, this method can be applied to the management of multiple blockchain-based application services within a multi-chain management platform in a smart city scenario, enabling the construction, application, and auditing of the blockchain management platform for stakeholders of the multi-chain management platform, such as managers, designers, and blockchain solution providers of smart city multi-business systems.

[0121] For ease of understanding, the system architecture of this application is illustrated below using a smart city scenario as an example.

[0122] As shown in Figure 1, in a smart city scenario, urban blockchain applications can include a variety of blockchain-based application services, such as public services, public safety services, urban governance services, and business environment management services. Public services provide electronic certificates and receipts. Public safety services enable hazardous material traceability and emergency response capabilities. Urban governance services provide smart transportation services, judicial evidence storage services, and public finance services. Business environment management services enable data sharing, government approvals, and government disclosures.

[0123] City blockchain applications can be built on a unified blockchain as a service (uBaaS). Accordingly, these applications can be integrated with the unified blockchain infrastructure to achieve their desired functionality. The unified blockchain infrastructure can be logically divided into a business layer, an adaptation layer, and a chain data layer. The functions of these three layers are described below.

[0124] The business layer can be divided into the tenant plane and the management plane. The tenant plane can provide at least one of the following: chain management capabilities, smart contract management capabilities, application ecosystem and integration capabilities, data asset and configuration management capabilities, or operations and maintenance monitoring capabilities. It should be noted that the chain management and operations and maintenance monitoring capabilities of the tenant plane can be global capabilities, for example, supporting the management of blockchains with different architectures. The management plane provides at least one of the following: resource governance and operations monitoring capabilities, identity and process management capabilities, or business ecosystem management capabilities. Resources can be hardware and software resources, including but not limited to computing power, storage resources, and network resources.

[0125] The adaptation layer includes authentication services, certificate management services, heterogeneous access services, and cross-chain services. The authentication service is used to manage tenants or users. Furthermore, the authentication service also supports permission management, such as assigning permissions to tenants or users. The authentication service can also connect to third-party authentication services and use them for authentication. Certificate management services can include certificate issuance, certificate renewal, and certificate revocation (such as certificate deletion or destruction). Heterogeneous access services are used to provide basic blockchain as a service (BaaS) access and basic BaaS adaptation.

[0126] Cross-chain services include cross-chaining between heterogeneous chains, specifically between heterogeneous blockchain networks. Furthermore, cross-chain services also support cross-chaining between homogeneous blockchain networks, such as between blockchain networks built on the same BaaS. It should be noted that cross-chain services also provide an oracle mechanism. Oracles write external information (off-chain and off-chain data) into the blockchain, enabling data exchange between the blockchain and the real world. Oracles allow deterministic smart contracts to react to the uncertain external world. They serve as a means for smart contracts to exchange data with the outside world and as an interface for data exchange between the blockchain and the real world.

[0127] The chain data layer includes the chain management platform. This platform provides the underlying blockchain technology, blockchain management, and operations and monitoring capabilities. Unlike the tenant-level chain management and operations monitoring capabilities of the business layer, the chain management platform's blockchain management and operations monitoring capabilities are localized, encompassing, for example, the platform's management and operations monitoring of the blockchain. The chain data layer is also compatible with other standardized blockchains. Furthermore, it provides standardized interfaces to mask differences between different blockchain interfaces (such as the service interface in Figure 1).

[0128] The cross-chain system of the present application can be constructed using the cross-chain service shown in Figure 1. The cross-chain service can deploy a cross-chain component on at least one node in a blockchain network based on user (e.g., administrator) configuration, forming a cross-chain node (CC Node). As shown in Figure 2, the node is deployed with a smart contract and maintains a distributed ledger. When conducting a transaction, the node can, based on a consensus algorithm, reach consensus with other participating nodes in the blockchain network and then record the transaction in the form of a block in the distributed ledger. The node can process the transaction using cryptographic mechanisms and record it in the distributed ledger to ensure security. The cross-chain component is used to provide cross-chain management capabilities, such as enabling cross-chain transactions. It also provides cross-chain identity management and cross-chain permission management. Cross-chain identity management includes managing the identity information (chain information) of registered blockchain networks, and cross-chain permission management includes managing the cross-chain access permission information of registered blockchain networks. The cross-chain component can execute cross-chain transactions when cross-chain identity authentication and / or cross-chain permission verification are passed. For example, if the cross-chain transaction type is a query, the cross-chain component can forward the cross-chain transaction request to execute the cross-chain transaction. Another example is a cross-chain write transaction, such as adding data across the chain, where the cross-chain component can record the transaction information in the distributed ledger. This transaction information can include the source and destination addresses, and further, the transaction object, such as digital assets or data.

[0129] In some possible implementations, the cross-chain component may also include an agent. This agent is primarily used to monitor cross-chain transaction requests and is therefore also referred to as a cross-chain agent (cc agent). The cc agent can serve as a proxy for different heterogeneous blockchain networks, supporting the encapsulation of existing heterogeneous blockchain network (heterogeneous chains) interaction interfaces based on a universal interaction protocol, thereby shielding the differences between different blockchain networks. This method decouples the function of monitoring cross-chain transaction requests from other functions. When a cross-chain transaction request is monitored, other functional modules are awakened, which can reduce the overall power consumption (or resource consumption) of the cross-chain component and improve its availability.

[0130] By deploying cross-chain components on nodes, heterogeneous blockchain networks can interact through cross-chain component protocols, such as gossip. Gossip is a communication protocol that allows for shared state in distributed systems, disseminating information to all members of a network or cluster. The gossip protocol works by periodically selecting random nodes and passing information to them. The nodes that receive the information then proceed with the aforementioned process of selecting and passing information to the selected nodes.

[0131] Specifically, the cross-chain components of a cross-chain node can discover other cross-chain nodes based on a registration and discovery mechanism, thereby forming a synchronized network (or cross-chain node network) with the cross-chain components of other cross-chain nodes. Specifically, the registration and discovery mechanism may include registration and discovery. Registration may involve registering the chain information of a blockchain network providing a service, such as at least one of a blockchain address or certificate, with a public component. For ease of description, this application may refer to the blockchain network deploying the public components as the main blockchain network, referred to as the main chain, and the blockchain networks registered with the main chain as sub-blockchain networks, referred to as sub-chains. Public components may be cross-chain components of the main blockchain network. Discovery may involve ensuring that sub-blockchain networks (or cross-chain nodes of sub-blockchain networks) registered with the main blockchain network can be discovered by other callers in a timely manner. It should be noted that discovery may include discovering that nodes (such as cross-chain nodes) of a sub-blockchain network have come online, or discovering that nodes (such as cross-chain nodes) of a sub-blockchain network have gone offline.

[0132] For ease of understanding, this application also provides an example of building a cross-chain system based on a mainchain and subchains. As shown in Figure 3, the cross-chain system includes a first blockchain network, a second blockchain network, and a third blockchain network. The first blockchain network is the main blockchain network, hereinafter referred to as mainchain A, and the second and third blockchain networks are sub-blockchain networks, hereinafter referred to as subchains A and B. The mainchain, subchains A, and B can all synchronize data within the blockchain network through a gossip network. In this example, subchains A and B can be heterogeneous blockchain networks. Cross-chain components are deployed on nodes in the mainchain, subchains A, and B, forming a synchronized network. The synchronized network can use the gossip protocol to broadcast messages between cross-chain components to ensure reachability. It should be noted that direct channels can also be established within the synchronized network. If the address is unknown (for example, the destination address), the gossip protocol can be used to broadcast. Once the address is synchronized, a direct channel can be established, which can be used to transmit cross-chain transactions. For example, if the two parties conducting a cross-chain transaction initiate multiple cross-chain transactions within a period of time, they can transmit subsequent transactions in multiple cross-chain transactions through the direct channel after establishing a direct channel.

[0133] The following describes the architecture of the cross-chain system, taking into account application scenarios. A general cross-chain system architecture is shown in Figure 4. Figure 4 illustrates this using a smart city application. The cross-chain system comprises multiple business chains for different businesses, each of which can be a consortium chain managed by a different organization. In this example, the public security business chain includes nodes managed by Enterprise A, Enterprise C, and the public security organization. The market supervision business chain includes nodes managed by Enterprise B, Enterprise D, and the taxation organization. In addition to the public security and market supervision business chains, another business chain serves as a relay chain for the public security and market supervision business chains. The relay chain can include nodes managed by other organizations, such as finance and civil affairs.

[0134] The aforementioned business chains can be connected to business applications. For example, the public security business chain can be connected to public security system applications, and the market supervision business chain can be connected to tax system applications. The aforementioned business applications can be developed based on the corresponding business chain's software development kit (SDK) or application programming interface (API). The business chain is deployed with business contracts, specifically business-related smart contracts. At least one node in the business chain is deployed with cross-chain components and cross-chain contracts. Among them, cross-chain components include agents, such as cross-chain agents, which are used to communicate with cross-chain components deployed on nodes of other business chains, or communicate with the relay chain, for example, communicating with the relay chain through the relay chain's cross-chain components.

[0135] After deploying cross-chain components and cross-chain contracts, nodes on the business chain can register the business chain's chain information and cross-chain access rights information on the main blockchain network. The main blockchain network can maintain registration information (such as the chain information and cross-chain access rights information) and routing information, and perform permission management. Routing information can include the business chain's routing path or routing address.

[0136] In Figure 4, different types of blockchain networks have no shared nodes, and all message interactions can be implemented through cross-chain components. For example, message interactions between business chains or between a business chain and the relay chain can be implemented through cross-chain components (or their proxies, such as cross-chain proxies). The relay chain is deployed with cross-chain components, and each business chain adapts to the relay chain's deployed components and registers chain information with the relay chain to enable cross-chain component-based interactions. It should be noted that when cross-chain components or proxies interact with each other, they can also forward messages through a router. Furthermore, the router can be connected to the management plane to facilitate management of the cross-chain system.

[0137] It should be noted that the phrase "no shared nodes" between a sub-blockchain network and the main blockchain network in a cross-chain system refers to the fact that the sub-blockchain network and the main blockchain network share no shared nodes, and does not imply that the main blockchain network or the sub-blockchain network itself has no shared nodes. In some possible implementations, the main blockchain network or the sub-blockchain network may share nodes with other blockchain networks outside the cross-chain system.

[0138] For ease of understanding, the following example illustrates this. As shown in Figure 5, the main chain and subchains 1, 2, and 3 are deployed with cross-chain components and cross-chain contracts. Subchains 1 and 3 do not share nodes with the main chain, while subchain 2 does share nodes with the main chain. A cross-chain management system or service can register the chain information of subchains 1 and 3 on the main chain (e.g., the main chain's cross-chain component) based on configuration by a user (e.g., an administrator), thereby forming a cross-chain system. The cross-chain system includes the main chain, subchain 1, and subchain 3 described above. The cross-chain components of subchains 1 and 3 can also be configured with the main chain address and certificate. This certificate may include, but is not limited to, Transport Layer Security (TLS). TLS certificates protect internet connections by encrypting data sent between the browser, the website being visited, and the website server, ensuring that data is transmitted privately and cannot be modified, lost, or stolen.

[0139] In a cross-chain system, blockchain applications connected to subchains can initiate cross-chain transactions by calling cross-chain contracts through APIs. For example, a blockchain application connected to Subchain 1 can initiate a cross-chain transaction from Subchain 1 to Subchain 3 by calling a cross-chain contract through an API. Subchain 1's cross-chain component intercepts the cross-chain transaction request and routes it to the mainchain. The mainchain performs identity and permission verification on the cross-chain transaction request. Specifically, it verifies the legality of the identities of both parties to the transaction, such as whether they are registered on the mainchain, and verifies Subchain 1's permission to access Subchain 3. If verification is successful, the mainchain's cross-chain component transmits the cross-chain transaction request to the mainchain's nodes for consensus. Once the mainchain's nodes reach consensus on the cross-chain transaction, they record the cross-chain transaction information in the mainchain's ledger (blockchaining). The mainchain's cross-chain component can synchronize the execution status of the cross-chain transaction on the mainchain with the cross-chain component of Subchain 3, thereby notifying Mainchain 3 to record the cross-chain transaction information in the mainchain's ledger. Furthermore, sub-chain 3 successfully records the transaction information of the cross-chain transaction to the ledger of sub-chain 3, and can also notify sub-chain 1 to record the transaction information of the cross-chain transaction to the ledger of sub-chain 1.

[0140] It should be noted that if a blockchain network shares nodes with the aforementioned cross-chain system, it can also achieve cross-chain transactions. For example, Subchain 2 shares nodes with the main chain. The blockchain application connected to Subchain 2 can invoke a cross-chain contract via an API to initiate a cross-chain transaction from Subchain 2 to Subchain 3. Because Subchain 2 and the main chain share nodes, the shared node can receive the cross-chain transaction request, which is then forwarded to the main chain. The main chain's cross-chain component can authenticate and verify the cross-chain transaction request. Once verification is successful, the main chain's nodes can reach consensus on the cross-chain transaction. Once consensus is reached, the cross-chain transaction information can be recorded in the main chain's ledger. The main chain's cross-chain component can then notify Main Chain 3 to record the cross-chain transaction information in the main chain's ledger.

[0141] For blockchain networks with shared nodes, cross-chain can also be achieved through other methods, which are not limited in this embodiment.

[0142] Based on the above cross-chain system, this application also provides a cross-chain transaction method. The cross-chain transaction method of this application is introduced below with reference to the accompanying drawings.

[0143] Referring to the flowchart of a cross-chain transaction method shown in FIG6 , the method is applied to a cross-chain system, where the cross-chain system includes a first blockchain network, a second blockchain network, and a third blockchain network, where the second blockchain network and the third blockchain network are heterogeneous blockchain networks. The method includes the following steps:

[0144] S602: The cross-chain component of the second blockchain network monitors cross-chain transaction requests.

[0145] Cross-chain transactions refer to transactions across different blockchain networks, and cross-chain transactions refer to transactions between different blockchain networks. For example, a cross-chain transaction might involve transferring a first amount of digital assets from a banking business chain and a second amount of digital assets to a live streaming business chain. A cross-chain transaction request is used to request a cross-chain transaction, such as a cross-chain transaction from a second blockchain network to a third blockchain network. A cross-chain transaction request can be generated by a blockchain application invoking a cross-chain contract. The cross-chain transaction request may include transaction information, such as the source and destination addresses of the cross-chain transaction. The source address may be the address of the initiator of the cross-chain transaction, and the destination address may be the address of the counterparty to the initiator. For example, the source address may be an address on the second blockchain network, and the destination address may be an address on the third blockchain network.

[0146] In a specific implementation, the cross-chain component of the second blockchain network can obtain transaction information for all transactions synchronized with the second blockchain network. By identifying this information, it can identify cross-chain transaction requests. During runtime, the cross-chain node can load a cross-chain contract. This cross-chain contract supports hash locking of the current cross-chain transaction and marks any cross-chain transaction as a cross-chain type. Based on this, the cross-chain component can identify cross-chain transaction requests based on the cross-chain contract. Cross-chain transaction requests are generated by calling the cross-chain contract. The cross-chain component of the second blockchain network can identify cross-chain transaction requests by monitoring the contract information in the cross-chain transaction request. Alternatively, the cross-chain component of the second blockchain network can monitor the cross-chain contract call interface to listen for cross-chain contract requests.

[0147] Cross-chain components can include proxies, such as the cross-chain proxy. Acting as a proxy for users' heterogeneous blockchain networks, the cross-chain proxy encapsulates the interaction interfaces of heterogeneous blockchain networks based on a common interaction protocol, shielding the differences between different blockchain networks and thus enabling monitoring of heterogeneous blockchain networks.

[0148] S604. The cross-chain component of the second blockchain network routes the cross-chain transaction request to the cross-chain component of the first blockchain network according to the routing address.

[0149] Specifically, the cross-chain component of the second blockchain network can parse the cross-chain transaction request, obtain the routing address, and then route the cross-chain transaction request to the cross-chain component of the first blockchain network according to the routing address. Furthermore, the cross-chain component of the second blockchain network can also query the execution status of the cross-chain transaction, such as the execution status of the cross-chain transaction on the current blockchain network, trigger synchronization based on the execution status, and route the cross-chain transaction request to the cross-chain component of the first blockchain network.

[0150] It should be noted that the above S602 to S604 are one implementation method for the cross-chain component of the first blockchain network to obtain the cross-chain transaction request. In other possible implementation methods of the embodiment of the present application, the cross-chain component of the first blockchain network can also obtain the cross-chain transaction request through other methods. For example, when there is a shared node between the first blockchain network and other blockchain networks, the cross-chain transaction request can also be obtained through the shared node, as shown in Figure 5.

[0151] S606: The cross-chain component of the first blockchain network performs identity authentication and permission verification based on the cross-chain transaction request and obtains a verification result. If the verification result indicates that the verification is successful, S608 is executed.

[0152] Specifically, the cross-chain component of the first blockchain network listens to the cross-chain transaction request, can parse the cross-chain transaction request, and obtain the source address and destination address of the cross-chain transaction. The cross-chain component of the first blockchain network can compare the source address and / or destination address with the address in the registration information for identity verification. When the source address and destination address match in the registration information, it means that the identity verification is successful. When the source address or destination address does not match in the registration information, it means that the identity verification fails. Similarly, the cross-chain component of the first blockchain network can match the source address, destination address and the information of the contract authorized to access in the registration information (information of the distributed ledger). When the match is successful, it means that the two parties to the transaction have deployed the same cross-chain contract, and access can be made through the cross-chain contract, thereby determining that the permission verification is successful. When the match is unsuccessful, it means that the permission verification fails.

[0153] Specifically, the cross-chain component of the first blockchain network can store the chain information and cross-chain access permission information of the second blockchain network, as well as the chain information and cross-chain access permission information of the third blockchain network, when registering the second blockchain network and the third blockchain network. The chain information can be address information, such as an address in the blockchain network. It should be noted that the first blockchain network can record the chain information and cross-chain access permission information of the second blockchain network, as well as the chain information and cross-chain access permission information of the third blockchain network, in the ledger of the first blockchain network for auditing or querying the status (valid or invalid, or whether it has lost activity) or permission information of nodes (such as cross-chain nodes) in the registered blockchain networks.

[0154] S608. When the nodes of the first blockchain network reach a consensus on the cross-chain transaction, the cross-chain component of the first blockchain network records the transaction information of the cross-chain transaction in the ledger of the first blockchain network.

[0155] Specifically, the cross-chain component of the first blockchain network can identify the transaction type of the cross-chain transaction, which can include cross-chain query (such as cross-chain read) and cross-chain write (such as cross-chain data addition). Then, the cross-chain component of the first blockchain network can execute the cross-chain transaction based on the transaction type. When the transaction type is a cross-chain query, the cross-chain component of the first blockchain network forwards the cross-chain transaction request, for example, forwarding the cross-chain transaction request according to the destination address of the cross-chain transaction request, without performing a transaction record operation on the cross-chain transaction request (i.e., without the need for block placement). When the transaction type is a cross-chain write, the cross-chain component of the first blockchain network can perform a transaction record operation on the cross-chain transaction. The following describes the process by which the cross-chain component of the first blockchain network performs a transaction record operation on a cross-chain transaction.

[0156] Specifically, the cross-chain component of the first blockchain network can trigger consensus on a cross-chain transaction request on the first blockchain network. When the nodes of the first blockchain network reach consensus on the cross-chain transaction in the cross-chain transaction request, the transaction information of the cross-chain transaction can be recorded in the ledger of the first blockchain network. The transaction information recorded in the ledger of the first blockchain network can be complete. For example, a cross-chain transaction involves transferring a first amount of a first digital asset from account A on the second blockchain network and transferring a second amount of a second digital asset to account B on the third blockchain network. The ledger of the first blockchain network can then record the following transaction information: account A on the first blockchain network transfers the first amount of the first digital asset, and account B on the second blockchain network transfers the second amount of the second digital asset.

[0157] In some possible implementations, the cross-chain component of the first blockchain network may first query the execution status of the cross-chain transaction, for example, by communicating with the cross-chain component of the second blockchain network to obtain the execution status of the cross-chain transaction on the second blockchain network. The cross-chain component of the first blockchain network may then record the cross-chain transaction based on the execution status of the cross-chain transaction on the second blockchain network. For example, the cross-chain component of the first blockchain network may record the cross-chain transaction when the cross-chain transaction is locked on the second blockchain network.

[0158] In order to improve reliability, the first blockchain network can usually set up two or more cross-chain nodes. In this way, when one cross-chain node fails, the other cross-chain nodes can still execute cross-chain transactions.

[0159] S608. The cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0160] The cross-chain component of the first blockchain network can successfully record the transaction information of the cross-chain transaction in the ledger of the first blockchain network, and notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network, so as to achieve multi-chain data consistency.

[0161] The first blockchain network's successful recording of the cross-chain transaction information in its ledger indicates that the cross-chain transaction's execution status on the first blockchain network is complete or successful. The cross-chain component of the first blockchain network can send the execution status to the second blockchain network to notify the cross-chain component of the third blockchain network to record the cross-chain transaction information in the third blockchain network's ledger.

[0162] In some possible implementations, the cross-chain component of the first blockchain network, the second blockchain network component, and the third blockchain network component form a synchronous network. For example, the cross-chain components can form a synchronous network (or referred to as a gossip network) through the gossip protocol. The cross-chain component of the first blockchain network can broadcast a notification message through the synchronous network, which is used to notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network. In some examples, the notification message may include the execution status of the cross-chain transaction on the first blockchain network. In other examples, the notification message may include instruction information, which is used to instruct the recording of the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0163] In other possible implementations, a direct channel is established between the cross-chain component of the first blockchain network and the cross-chain component of the third blockchain network. For example, if an address is synchronized during a previous cross-chain transaction, a direct channel can be established between the cross-chain component of the first blockchain network and the cross-chain component of the third blockchain network based on the address. Accordingly, the cross-chain component of the first blockchain network can notify the cross-chain component of the third blockchain network through the direct channel to record the transaction information of the cross-chain transaction in the third blockchain network's ledger.

[0164] Considering that a blockchain network or a cross-chain node within a blockchain network may fail or become inactive, to ensure verification accuracy, the cross-chain component of the first blockchain network can also detect the activity of the third blockchain network based on the chain information of the blockchain network registered with the first blockchain network, such as the third blockchain network. Specifically, the cross-chain component of the first blockchain network can detect the status of the cross-chain component in the third blockchain network through heartbeat detection, thereby detecting the activity of the third blockchain network. If the third blockchain network becomes inactive or exhibits abnormal activity, the chain information and cross-chain access rights information of the sub-blockchain network can be deleted or removed from the first blockchain network. The cross-chain component of the first blockchain network can periodically detect the activity of the registered blockchain network and periodically update the chain information and cross-chain access rights information registered on the first blockchain network. When the third blockchain network is active, the cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the third blockchain network's ledger.

[0165] S610. The cross-chain component of the third blockchain network records the transaction information of the cross-chain transaction to the ledger of the third blockchain network.

[0166] Specifically, the cross-chain component of the third blockchain network can forward cross-chain transaction requests to the third blockchain network, and the nodes of the third blockchain network can record the transaction information of the cross-chain transaction in the third blockchain network's ledger. The third blockchain network can obtain the execution status of the cross-chain transaction on the first blockchain network, and the third blockchain network can trust the first blockchain network, thereby recording the transaction information of the cross-chain transaction in the third blockchain network's ledger.

[0167] In some possible implementations, the cross-chain component of the third blockchain network records transaction information related to the third blockchain network in the third blockchain network's ledger. Continuing with the example of a cross-chain transaction involving a transfer of a first amount of a first digital asset from account A on the second blockchain network and a transfer of a second amount of a second digital asset to account B on the third blockchain network, the cross-chain component of the third blockchain network may record the following transaction information: Account B transfers the second amount of the second digital asset.

[0168] S612. The cross-chain component of the third blockchain network notifies the cross-chain component of the second blockchain network to record the transaction information of the cross-chain transaction in the ledger of the second blockchain network.

[0169] Upon successfully recording the transaction information of the cross-chain transaction in the third blockchain network's ledger, the cross-chain component of the third blockchain network may notify the cross-chain component of the second blockchain network to record the transaction information in the second blockchain network's ledger. Successful recording of the cross-chain transaction information in the third blockchain network's ledger by the third blockchain network indicates that the execution status of the cross-chain transaction on the third blockchain network is complete or successful. The cross-chain component of the third blockchain network may send the execution status to the second blockchain network to notify the cross-chain component of the second blockchain network to record the transaction information in the third blockchain network's ledger.

[0170] Similar to the first blockchain network notifying the third blockchain network, the third blockchain network's cross-chain component can broadcast a notification message via the synchronization network. This notification message is used to notify the second blockchain network's cross-chain component to record the transaction information of the cross-chain transaction in the second blockchain network's ledger. Alternatively, the third blockchain network's cross-chain component can establish a direct channel between the third blockchain network's cross-chain component and the second blockchain network's cross-chain component, and through this direct channel, notify the second blockchain network's cross-chain component to record the transaction information of the cross-chain transaction in the second blockchain network's ledger.

[0171] The cross-chain component of the third blockchain network can first obtain the activity (or status) of the second blockchain network, for example, by querying the activity of the second blockchain network from the first blockchain network. If the second blockchain network has not lost activity or is in a valid state, the cross-chain component of the third blockchain network will notify the cross-chain component of the second blockchain network to record the transaction information of the cross-chain transaction in the ledger of the second blockchain network. The first blockchain network can use a similar method to detect the activity of the third blockchain network to check the activity of the second blockchain network and store the activity of the second blockchain network.

[0172] S614. The cross-chain component of the second blockchain network records the transaction information of the cross-chain transaction to the ledger of the second blockchain network.

[0173] Specifically, the cross-chain component of the second blockchain network can forward the cross-chain transaction request to the second blockchain network, and the nodes of the second blockchain network can record the transaction information of the cross-chain transaction in the ledger of the second blockchain network. The second blockchain network can obtain the execution status of the cross-chain transaction on the third blockchain network, and the third blockchain network can trust the second blockchain network, thereby recording the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0174] In some possible implementations, the cross-chain component of the second blockchain network records transaction information related to the second blockchain network in the cross-chain transaction in the second blockchain network's ledger. Continuing with the example of a cross-chain transaction involving a transfer of a first amount of a first digital asset from account A on the second blockchain network and a transfer of a second amount of a second digital asset to account B on the third blockchain network, the cross-chain component of the second blockchain network may record the following transaction information: Account A transfers the first amount of the first digital asset.

[0175] It should be noted that the above steps S610, S612, and S614 are optional steps in the embodiment of the present application. The cross-chain transaction method of the embodiment of the present application can also be executed without performing the above steps, or by other means. For example, the second blockchain network and the third blockchain network can also record the transaction information of the cross-chain transaction through a consensus algorithm.

[0176] Based on the above description, the cross-chain transaction method of this application improves the component model of heterogeneous chain cross-chain to construct a layer of node network based on any heterogeneous chain. Specifically, it is a cross-chain node network based on cross-chain components. By using the relay chain mode, efficient data synchronization between heterogeneous blockchain networks is achieved. This method uses cross-chain components on nodes and does not rely on third parties. It solves the problem that related cross-chain technologies rely on the endorsement of trusted third parties or require third-party relay chains to achieve cross-chain capabilities. It can meet business needs, especially the needs of transaction performance and transaction security.

[0177] Figure 6 describes the cross-chain transaction method from an interactive perspective. This cross-chain transaction method relies on a cross-chain system. This application also provides a method for constructing a cross-chain system. This method can be executed by a cross-chain management system. The following describes the cross-chain transaction method from the perspective of a cross-chain management system.

[0178] Referring to the flowchart of a cross-chain transaction method shown in FIG7 , the method is applied to a cross-chain system, the cross-chain system including a first blockchain network, a second blockchain network, and a third blockchain network, the second blockchain network and the third blockchain network being heterogeneous blockchain networks, and the method includes the following steps:

[0179] S702. The cross-chain management system deploys a cross-chain component on at least one node of the first blockchain network.

[0180] S703. The cross-chain management system configures the first blockchain network as the main blockchain network.

[0181] A cross-chain component is a component used to implement cross-chain functionality. A component encapsulates data and methods. Therefore, a cross-chain component can encapsulate chain information representing identity, cross-chain access rights information, and cross-chain methods. Furthermore, a cross-chain method can include a method for monitoring cross-chain requests. This method can be decoupled from other methods to form a proxy for the cross-chain component. As shown in Figure 2, when a cross-chain component includes a proxy, it also supports proxy management, such as configuring the proxy's monitoring period.

[0182] Specifically, the cross-chain management system may obtain the cross-chain component and then send the cross-chain component to at least one node of the first blockchain network, thereby remotely deploying the cross-chain component. In some examples, the cross-chain management system may also obtain the cross-chain component, send the cross-chain component to at least one node of the first blockchain network, and then the user may deploy the cross-chain component on the at least one node.

[0183] In some possible implementations, the cross-chain management system may also deploy a cross-chain contract on at least one node of the first blockchain network. A cross-chain contract is specifically a smart contract used to implement cross-chain transactions. Cross-chain contracts are often combined with business contracts to enable cross-chain transactions. For example, a blockchain application (a business blockchain application, referred to as a business application) can initiate a transaction through a business contract, which then calls a cross-chain contract to implement the cross-chain transaction.

[0184] Specifically, the cross-chain management system can receive node information of the first blockchain network configured by a user (e.g., a user of the first blockchain network). The node information is used to identify the nodes in the first blockchain network that participate in the cross-chain operation, and deploy cross-chain contracts and cross-chain components on the corresponding nodes based on the node information. The cross-chain management system can pre-install cross-chain contracts and cross-chain components, or remotely download cross-chain contracts and cross-chain components, and then deploy the cross-chain contracts and cross-chain components on the nodes corresponding to the node information. Nodes with cross-chain contracts and cross-chain components deployed can be used as cross-chain nodes.

[0185] The cross-chain management system can also receive user-configured type information and configure the first blockchain network as the main blockchain network (also called the main chain or cross-chain main chain). The main blockchain network can serve as a registration center to register the chain information of other blockchain networks so that blockchain networks can discover each other.

[0186] The first blockchain network may be a consortium chain jointly managed by multiple organizations. Specifically, the cross-chain management system may first create an organization and then, based on the created organization, create the first blockchain network. For example, the cross-chain management system may use a blockchain service (BaaS) to create the first blockchain network. The blockchain service (or blockchain architecture) used to create the first blockchain network (or main chain) may be a default one or may be configured by the user as needed, and this embodiment does not impose any restrictions on this.

[0187] To address reliability concerns, the cross-chain management system can deploy cross-chain contracts and cross-chain components on multiple nodes. This prevents single points of failure in cross-chain nodes within the first blockchain network, which could lead to failure of the entire cross-chain system. Based on this, the cross-chain management system can also check the status of the cross-chain component deployed on at least one node within the first blockchain network. Specifically, the cross-chain management system can monitor the status of the cross-chain component through heartbeat detection. The cross-chain management system can count the number of nodes with a normal cross-chain component status. Accordingly, the cross-chain management system determines the availability (or liveness, validity) of the first blockchain network based on the number of nodes with a normal cross-chain component status. For example, if the number of nodes with a normal cross-chain component status is less than or equal to 1, the cross-chain capability of the first blockchain network is unavailable (inactive or inoperative). Furthermore, cross-chain capability is also affected by the node status of cross-chain nodes. Therefore, the cross-chain management system can also monitor the status of cross-chain nodes. Accordingly, the cross-chain management system can determine the availability of the first blockchain network based on the status of the cross-chain nodes and the status of the cross-chain components within the first blockchain network.

[0188] S704. The cross-chain management system deploys a cross-chain component on at least one node of the second blockchain network.

[0189] Specifically, the cross-chain management system can receive node information of the second blockchain network configured by a user (e.g., a user of the second blockchain network). This node information is used to identify the nodes in the second blockchain network that participate in the cross-chain process. The cross-chain contract and cross-chain components are then deployed on the corresponding nodes based on the node information. By deploying cross-chain components, cross-chain capabilities can be built or enhanced for the nodes, making them cross-chain nodes. The cross-chain management system can also deploy a cross-chain contract on at least one node of the second blockchain network. The deployment process can refer to the deployment process of the first blockchain network and will not be repeated here.

[0190] Similar to the first blockchain network, the second blockchain network can be a consortium chain managed by multiple organizations. Specifically, the cross-chain management system can first create an organization and then, based on the created organization, create the second blockchain network. The cross-chain management system can use BaaS (Blockchain as a Service) to create the second blockchain network. The blockchain service used to create the second blockchain network can be the default one or user-configured.

[0191] It should be noted that the main chain serves as a relay chain, enabling cross-chain transactions between different sub-chains (heterogeneous chains). This does not mean that the main chain and sub-chains are heterogeneous blockchain networks. The main chain and sub-chains can be homogeneous or heterogeneous blockchain networks. Accordingly, the blockchain service used to create the second blockchain network can be the same as or different from the blockchain service used to create the first blockchain network. In addition, when the cross-chain management system uses the blockchain service to create the second blockchain network, it can create a blockchain network unrelated to the main chain organization. In this way, the first and second blockchain networks have no shared nodes.

[0192] S706. The cross-chain management system deploys a cross-chain component on at least one node of the third blockchain network to obtain a second sub-blockchain network.

[0193] Specifically, the cross-chain management system can receive node information of a third blockchain network configured by a user (e.g., a user of the second blockchain network). This node information is used to identify nodes in the third blockchain network that participate in the cross-chain process and deploy cross-chain components on the corresponding nodes based on the node information. The cross-chain management system can also deploy cross-chain contracts on at least one node of the third blockchain network.

[0194] The third blockchain network and the second blockchain network are heterogeneous blockchain networks. The cross-chain management system can initialize nodes of the third blockchain network in different ways. In some possible implementations, the cross-chain management system can use a different blockchain service (blockchain architecture) than the blockchain service (blockchain architecture) used to create the second blockchain network to create the third blockchain network. For example, if the cross-chain management system uses the first blockchain service to create the second blockchain network, it can use the second blockchain service to create the third blockchain network. The first and second blockchain services are blockchain services with different architectures. In some possible implementations, the cross-chain management system can create the second blockchain network using the blockchain service and create the third blockchain network using a non-blockchain service.

[0195] Furthermore, when the third blockchain network and the first blockchain network are heterogeneous blockchain networks, the cross-chain management system may also first adapt the cross-chain component or cross-chain contract before deploying the cross-chain component or cross-chain contract. Specifically, the cross-chain management system may download the cross-chain component from the first blockchain network, adapt the cross-chain component to the third blockchain network, and then deploy and adapt the cross-chain component on at least one node of the third blockchain network. Similarly, the third blockchain network may download the cross-chain contract from the first blockchain network, adapt the cross-chain contract to the third blockchain network, and then deploy and adapt the cross-chain contract on at least one node of the third blockchain network.

[0196] The above S704 and S706 can be executed in parallel or in sequence according to the set order, and this embodiment of the application does not limit this. In addition, when the first blockchain network and the second blockchain network are created using the same blockchain service, the above S702 and S704 can be executed in parallel or in sequence according to the set order.

[0197] S708. The cross-chain management system registers the chain information and cross-chain access permission information of the first sub-blockchain network in the first blockchain network.

[0198] S710. The cross-chain management system registers the chain information and cross-chain access permission information of the second sub-blockchain network in the first blockchain network.

[0199] For a blockchain network, chain information may include the address of the blockchain network. Furthermore, chain information may include the certificates of sub-blockchain networks. Cross-chain access permission information includes information about the distributed ledgers to which access is authorized or information about the contracts to which access is authorized. For example, cross-chain access permission information may include the identifier of the contract to which access is authorized.

[0200] Specifically, the cross-chain management system can respond to a registration request from a user (e.g., a user of the second blockchain network) by sending the chain information and cross-chain access permission information of the second blockchain network to the first blockchain network, for example, to the cross-chain component of the first blockchain network, for registration. The registration process for the third blockchain network is similar to that of the second blockchain network and will not be further described here. Cross-chain nodes can perform registration discovery between different nodes based on the registration information (e.g., chain information) of the main chain.

[0201] In some possible implementations, the cross-chain management system may further construct a synchronization network based on the gossip protocol. The synchronization network includes a cross-chain component deployed on at least one node, and the synchronization network is used to implement cross-chain transactions between the first sub-blockchain network and the second sub-blockchain network. Specifically, the cross-chain management system may receive user-configured protocol information. This protocol information may include the protocol type used by the cross-chain component for interaction, such as the gossip protocol. Accordingly, the cross-chain management system may configure the communication protocol of the cross-chain component based on the protocol information, such as the gossip protocol, to construct the synchronization network.

[0202] Based on the above description, this application provides a method for building a cross-chain system. This method deploys cross-chain components and cross-chain contracts on at least one node in a blockchain network to build or enhance the node's cross-chain capabilities, thereby forming a cross-chain node. The cross-chain components of a cross-chain node can be constructed through a registration and discovery mechanism to form a synchronous network layer based on any heterogeneous blockchain network. This synchronous network can use the relay chain model to achieve efficient data synchronization across heterogeneous blockchain networks. This method uses cross-chain components on the node and does not rely on third parties. This solves the problem that related cross-chain technologies rely on the endorsement of trusted third parties or require third-party relay chains to achieve cross-chain capabilities. It can meet business needs, especially those for transaction performance and transaction security.

[0203] In order to make the technical solution of this application clearer and easier to understand, this application also provides an application scenario to illustrate the cross-chain system construction method and cross-chain transaction method.

[0204] Figure 8 shows a schematic diagram of a cross-chain system and an application scenario for implementing cross-chain transactions based on the cross-chain system. In this scenario, administrators of different blockchain networks can create a main blockchain network and sub-blockchain networks, and deploy cross-chain contracts and components to form cross-chain nodes. The more cross-chain nodes available, the higher the reliability. Furthermore, administrators can register sub-blockchain network chain information and cross-chain access permission information on the main blockchain network to support the discovery and broadcast of nodes from different sub-blockchain networks.

[0205] The main execution process of the cross-chain system construction is as follows:

[0206] 1. User A on the main chain creates an organization and a blockchain network jointly managed by multiple organizations. The user configures multiple nodes in the blockchain network to deploy cross-chain contracts and cross-chain components, and configures the current blockchain network as the main chain.

[0207] Creating organizations, creating blockchain networks, deploying cross-chain contracts and components, and configuring the main chain can all be accomplished through the blockchain as a service-domain controller (BaaS-DOMC). BaaS-DOMC provides cross-chain services. Specifically, BaaS-DOMC receives configuration information from users on the main chain A, creates organizations, establishes a blockchain network managed by multiple organizations, deploys cross-chain contracts and components, and configures the current blockchain network as the main chain.

[0208] 2. BaaS-DOMC checks the node status and the status of the cross-chain components running in the node to determine the availability of the main chain.

[0209] BaaS-DOMC can detect the node status and cross-chain component status through heartbeat detection. If the detection result indicates that the main chain has only one normally functioning cross-chain component, or no normally functioning cross-chain component, it means that the main chain's cross-chain capability is unavailable.

[0210] 3. Based on the same BaaS-DOMC, the user of sub-chain B builds sub-chain B that is independent of the main chain organization, deploys cross-chain components on sub-chain B, and registers the chain information and authorized access rights information of sub-chain B on the main chain A.

[0211] 4. The user of subchain C initializes the node of subchain C.

[0212] Subchain C is a blockchain network built using a different approach than BaaS-DOMC. Furthermore, compared to the nodes on Mainchain A and Subchain B, the nodes on Subchain C are heterogeneous. The architecture, protocols, and data structures of Subchain C differ from those of Mainchain A and Subchain B.

[0213] 5. The user of subchain C downloads the cross-chain components and cross-chain contracts from mainchain A, adapts the cross-chain components, cross-chain contracts and subchain C, completes the cross-chain contract deployment and cross-chain component deployment on the subchain C side, registers the chain information of subchain C on the mainchain A side and configures the cross-chain access permission information.

[0214] Among them, downloading cross-chain components and cross-chain contracts, cross-chain component / cross-chain contract adaptation and deployment, and sub-chain registration can also be achieved through BaaS-DOMC. The specific implementation process can be referred to the relevant content description above.

[0215] After building a cross-chain system, cross-chain transactions can be implemented based on the cross-chain system. Cross-chain transactions rely on cross-chain components. Cross-chain components include controllers and agents, such as the cross-chain controller (CC-controller) and the cross-chain agent (CC-agent).

[0216] The main function of the cross-chain controller is to ensure the execution of cross-chain processes, support the query or writing of inter-chain data, manage the transaction status of cross-chain transactions, and achieve multimodal network synchronization with other cross-chain components. Its main execution process includes:

[0217] 1. The main chain’s cross-chain controller receives the registration information of sub-chain B and sub-chain C and saves the registration information.

[0218] 2. The main chain’s cross-chain controller checks the activity of sub-chains B and C based on the registration information.

[0219] Registration information can include chain information and cross-chain access permission information. The main chain's cross-chain controller can write this registration information to the main chain A's ledger for audit purposes. Furthermore, the main chain's cross-chain controller can establish inter-chain component communication based on this chain information and periodically monitor the activity of registered sub-chains using heartbeat messages. The main chain's cross-chain controller can also query the permissions and status of cross-chain nodes in registered sub-chains.

[0220] 3. The cross-chain controller of the main chain monitors cross-chain transaction requests, communicates with the cross-chain agent to query the cross-chain transaction execution status, and processes the cross-chain transaction according to the cross-chain transaction execution status.

[0221] Among them, query-type cross-chain transactions are not recorded in the local ledger, but are directly forwarded to the sub-blockchain network identified by the destination address. The specific implementation of cross-chain write-type cross-chain transactions can be seen in the description of the embodiment in Figure 6.

[0222] As a proxy for different heterogeneous sub-chains, the cross-chain proxy supports encapsulating the interaction interface of heterogeneous chains based on a universal interaction protocol, shielding the differences between different heterogeneous chains, and supporting monitoring of heterogeneous chains. Its main execution process includes:

[0223] The cross-chain agents of sub-chain B and sub-chain C monitor all cross-chain transaction requests of the current chain, and after being triggered based on the status, they route the cross-chain transaction requests to the main chain A according to the routing address of the cross-chain transaction request.

[0224] Among them, the cross-chain agents of sub-chain B and sub-chain C simultaneously establish links with the cross-chain components of the cross-chain counterparts and the cross-chain components of the main chain. Cross-chain transactions can be directly transmitted through the above links, and cross-chain transactions can be stored in the main chain's ledger after hash operation for auditing.

[0225] Based on the above description, the cross-chain transaction method of the present application can achieve data interaction between different blockchain networks by deploying cross-chain components on nodes of the blockchain network (as a subchain) where cross-chain transactions are required, and deploying cross-chain components on nodes of other blockchain networks (as the main chain). Through the synchronous network between the cross-chain components, data interaction between different blockchain networks can be achieved. For example, cross-chain interoperability can be achieved through asset transfer between different blockchain networks, cross-chain payment settlement, decentralized transactions, cross-chain reading and verification of the status or value of other chains (such as cross-chain trusted evidence collection in judicial applications), etc. This method does not require the introduction of third-party centralized nodes, and provides trustworthy, reliable, and efficient protection through the synchronous network between cross-chain components. This method can also achieve the freezing or locking of data (on-chain data) in blockchain networks. Taking the financial scenario as an example, this method can provide the ability to freeze or lock certain on-chain data based on information on a specific chain. Furthermore, the locking and unlocking conditions of on-chain data (such as assets) can be set. The locking and unlocking conditions can be linked to events or behaviors on other chains.

[0226] In addition, this method can use a two-layer architecture to break through the performance and functional bottlenecks of the public chain. The transaction speed and performance can meet business needs, providing more optimized options and higher scalability.

[0227] Based on the aforementioned cross-chain transaction method and cross-chain system construction method, this application provides a cross-chain system and a cross-chain management system. The following describes the cross-chain system and cross-chain management system of the embodiment of this application in conjunction with the accompanying drawings.

[0228] Referring to the architectural diagram of a cross-chain system shown in FIG3 , the cross-chain system includes a first blockchain network (e.g., main chain A in FIG3 ), a second sub-blockchain network (e.g., sub-chain B in FIG3 ), and a third blockchain network (e.g., sub-chain C in FIG3 ). The second blockchain network and the third blockchain network are heterogeneous blockchain networks, and the first blockchain network, the second blockchain network, and the third blockchain network respectively deploy cross-chain components.

[0229] The cross-chain component of the first blockchain network is configured to obtain a cross-chain transaction request, wherein the cross-chain transaction request is used to request execution of a cross-chain transaction from the second blockchain network to the third blockchain network, perform identity authentication and permission verification based on the cross-chain transaction request, and obtain a verification result;

[0230] The cross-chain component of the first blockchain network is further configured to, when the verification result indicates that the verification is passed and the nodes of the first blockchain network reach a consensus on the cross-chain transaction, record the transaction information of the cross-chain transaction in the ledger of the first blockchain network, and notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0231] In some possible implementations, the cross-chain component of the first blockchain network, the second blockchain network component, and the third blockchain network component form a synchronous network, and the cross-chain component of the first blockchain network is specifically used to:

[0232] A notification message is broadcast through the synchronization network, where the notification message is used to notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0233] In some possible implementations, cross-chain components in the synchronization network synchronize messages through a gossip protocol.

[0234] In some possible implementations, a direct channel is established between the cross-chain component of the first blockchain network and the cross-chain component of the third blockchain network;

[0235] The cross-chain component of the first blockchain network is specifically used to:

[0236] Notify the cross-chain component of the third blockchain network through the direct channel to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0237] In some possible implementations, the cross-chain component of the first blockchain network is further used to:

[0238] Identify the transaction type of the cross-chain transaction;

[0239] The cross-chain component of the first blockchain network is specifically used to:

[0240] When the transaction type is cross-chain write, the transaction information of the cross-chain transaction is recorded in the ledger of the first blockchain network.

[0241] In some possible implementations, the cross-chain component of the third blockchain network is specifically used to:

[0242] When the transaction information of the cross-chain transaction is successfully recorded in the ledger of the third blockchain network, the cross-chain component of the second blockchain network is notified to record the transaction information of the cross-chain transaction in the ledger of the second blockchain network.

[0243] In some possible implementations, the cross-chain component of the first blockchain network is further configured to:

[0244] Receive the chain information and cross-chain access permission information of the second blockchain network and the chain information and the cross-chain access permission information of the third blockchain network, and record the chain information and cross-chain access permission information of the second blockchain network and the chain information and the cross-chain access permission information of the third blockchain network in the ledger of the first blockchain network.

[0245] In some possible implementations, the cross-chain component of the first blockchain network is further configured to:

[0246] Detecting the validity of the third blockchain network based on the chain information of the third blockchain network;

[0247] The cross-chain component of the first blockchain network is specifically used to:

[0248] When the third blockchain network is valid, notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

[0249] In some possible implementations, the cross-chain component of the first blockchain network is specifically used to:

[0250] Receive a cross-chain transaction request routed by the cross-chain component of the second blockchain network according to the routing address.

[0251] In some possible implementations, the cross-chain component includes an agent and a controller, wherein the agent encapsulates the interaction interface of the heterogeneous blockchain network based on a universal interaction protocol;

[0252] The cross-chain component of the second blockchain network is used to:

[0253] The cross-chain transaction request is monitored through the universal interaction protocol.

[0254] Next, referring to the schematic structural diagram of a cross-chain management system shown in FIG9 , the cross-chain management system 900 is used to build a cross-chain system. The cross-chain system includes a first blockchain network, a second sub-blockchain network, and a third sub-blockchain network. The second blockchain network and the third blockchain network are heterogeneous blockchain networks. The cross-chain management system 900 includes:

[0255] A deployment module 902 is configured to deploy a cross-chain component on at least one node of the first blockchain network, deploy the cross-chain component on at least one node of the second blockchain network, and deploy the cross-chain component on at least one node of the third blockchain network;

[0256] Registration module 904 is used to register the chain information and cross-chain access permission information of the second blockchain network in the first blockchain network, and to register the chain information and cross-chain access permission information of the third blockchain network in the first blockchain network. The chain information of the second blockchain network is used by the cross-chain component of the third blockchain network to discover the second blockchain network, and the chain information of the third blockchain network is used by the cross-chain component of the second blockchain network to discover the third blockchain network.

[0257] Exemplarily, the deployment module 902 and the registration module 904 may be implemented by hardware or software.

[0258] When implemented through software, the deployment module 902 and the registration module 904 are applications running on a computing device, such as a computing engine. Applications can be provided in the form of virtualization services. Virtualization services can include virtual machine (VM) services, bare metal server (BMS) services, and container services. Among them, VM services can be services that use virtualization technology to virtualize a virtual machine resource pool on multiple physical hosts to provide VMs for users to use on demand. BMS services are services that virtualize a BMS resource pool on multiple physical hosts to provide BMSs for users to use on demand. Container services are services that virtualize a container resource pool on multiple physical hosts to provide containers for users to use on demand. A VM is a simulated virtual computer, that is, a logical computer. BMS is a high-performance computing service that is elastically scalable and has computing performance no different from that of a traditional physical machine, with the characteristics of secure physical isolation. Containers are a kernel virtualization technology that can provide lightweight virtualization to achieve the purpose of isolating user space, processes, and resources. It should be understood that the VM service, BMS service and container service in the above-mentioned virtualization services are only specific examples. In actual applications, virtualization services can also be other lightweight or heavyweight virtualization services, which are not specifically limited here.

[0259] When implemented through hardware, the deployment module 902 and the registration module 904 may include at least one computing device, such as a server. Alternatively, the deployment module 902 and the registration module 904 may be implemented using an application-specific integrated circuit (ASIC) or a programmable logic device (PLD). The PLD may be a complex programmable logical device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0260] In some possible implementations, the deployment module 902 is specifically configured to:

[0261] Downloading the cross-chain component from the first blockchain network;

[0262] Adapting the cross-chain component to the third blockchain network;

[0263] Deploy the adapted cross-chain component on at least one node of the third blockchain network.

[0264] In some possible implementations, the system 900 further includes:

[0265] The status management module 906 is used to check the status of the cross-chain component deployed on at least one node in the first blockchain network, and determine the availability of the first blockchain network based on the number of nodes where the cross-chain component is in a normal state.

[0266] The state management module 906 may be implemented in hardware or software. When implemented in software, the state management module 906 may be an application running on a computing device, such as a computing engine. The application may be provided as a virtualized service, such as a VM or container service. When implemented in hardware, the state management module 906 may include at least one computing device, such as a server. Alternatively, the state management module 906 may be implemented using an application-specific integrated circuit (ASIC) or a programmable logic device (PLD).

[0267] In some possible implementations, the system 900 further includes:

[0268] Configuration module 908 is used to configure the first blockchain network as a main chain, and the main chain is used to relay cross-chain transactions between the second blockchain network and the third blockchain network.

[0269] The configuration module 908 may be implemented in hardware or software. When implemented in software, the configuration module 908 may be an application running on a computing device, such as a computing engine. The application may be provided as a virtualized service, such as a VM or container service. When implemented in hardware, the configuration module 908 may include at least one computing device, such as a server. Alternatively, the configuration module 908 may be implemented using an application-specific integrated circuit (ASIC) or a programmable logic device (PLD).

[0270] In some possible implementations, the system 900 further includes:

[0271] The creation module 909 is used to create the second blockchain network using the first blockchain service, and to create the third blockchain network using the second blockchain service, where the second blockchain network and the third blockchain network are heterogeneous blockchain networks.

[0272] The cross-chain management system 900 can be applied to cloud scenarios (or cloud architecture) or non-cloud scenarios (or non-cloud architecture). The following examples illustrate the application of the cross-chain management system 900 to cloud scenarios and non-cloud scenarios.

[0273] When applied in a cloud scenario, the cross-chain management system 900 can collaborate with blockchain services to build a cross-chain system. Specifically, the cross-chain management system 900 can also include a creation module 909, which is used to create a second blockchain network using the first blockchain service, and to create a third blockchain network using the second blockchain service, wherein the second blockchain network and the third blockchain network are heterogeneous blockchain networks. In a specific implementation, the first blockchain service can be a basic BaaS service (such as a BaaS service built into the system or platform), and the second blockchain service can be a third-party BaaS service.

[0274] Furthermore, the first blockchain service and the second blockchain service can provide standardized interfaces. Accordingly, the creation module 909 can call the first blockchain service through the standardized interface to create the second blockchain network, and use the standardized interface to call the second blockchain service to create the third blockchain network.

[0275] The aforementioned blockchain network can be a consortium chain between multiple organizations. A consortium chain can be considered a cluster of multiple private chains, a type of blockchain network jointly managed by multiple organizations (or institutions). Each organization manages one or more nodes, and data stored in the consortium chain is only accessible to the participating organizations. Each node in a consortium chain typically has a corresponding organization, and organizations can only join or exit the network after authorization. It should be noted that when creating a first or second blockchain network, it is possible to create a blockchain network independent of the organization of the primary blockchain network. This means that the first and second blockchain networks share no nodes with the primary blockchain network.

[0276] When applied to non-cloud scenarios, the cross-chain management system can deploy cross-chain contracts and cross-chain components for the created blockchain network, configure one of the blockchain networks as the main blockchain network, and register the chain information and cross-chain access permission information of other blockchain networks (sub-blockchain networks) to the cross-chain components of the main blockchain network.

[0277] In some possible implementations, the first blockchain service and the second blockchain service provide standardized interfaces, and the creation module 909 is specifically configured to:

[0278] The first blockchain service is called through the standardized interface to create the second blockchain network, and the second blockchain service is called through the standardized interface to create the third blockchain network.

[0279] In some possible implementations, the creation module 909 is specifically configured to:

[0280] The second blockchain network is created using the first blockchain service, independent of the organization of the first blockchain network.

[0281] This application also provides a computing device 1000. As shown in Figure 10, computing device 1000 includes a bus 1002, a processor 1004, a memory 1006, and a communication interface 1008. Processor 1004, memory 1006, and communication interface 1008 communicate with each other via bus 1002. Computing device 1000 can be a server or a terminal device. It should be understood that this application does not limit the number of processors and memories in computing device 1000.

[0282] Bus 1002 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, among others. Buses may be classified as address buses, data buses, control buses, and the like. For ease of illustration, FIG10 illustrates a single bus line, but this does not imply a single bus or type of bus. Bus 1002 may include a path for transmitting information between various components of computing device 1000 (e.g., memory 1006, processor 1004, and communication interface 1008).

[0283] The processor 1004 may include any one or more processors such as a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor (MP), or a digital signal processor (DSP).

[0284] The memory 1006 may include volatile memory, such as random access memory (RAM). The memory 1006 may also include non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid state drive (SSD).

[0285] Memory 1006 stores executable program code, and processor 1004 executes the executable program code to implement the aforementioned cross-chain transaction method. Specifically, memory 1006 stores instructions for the cross-chain system to execute the cross-chain transaction method. For example, memory 1006 may store instructions for the cross-chain component of the first blockchain network in the cross-chain system to execute the cross-chain transaction method, or may store instructions for the cross-chain component of the second blockchain network or the third blockchain network in the cross-chain system to execute the cross-chain transaction method.

[0286] The communication interface 1008 uses a transceiver module such as, but not limited to, a network interface card or a transceiver to implement communication between the computing device 1000 and other devices or a communication network.

[0287] This application also provides another computing device. As shown in Figure 11, the difference between this computing device and Figure 10 lies in the memory. The memory 1006 of the computing device in Figure 11 can also store instructions for the cross-chain management system 900 to execute the cross-chain system construction method, such as the instructions for the deployment module 902 and the registration module 904. Furthermore, the memory 1006 can also store instructions for the state management module 906, the configuration module 908, and the creation module 909.

[0288] Embodiments of the present application also provide a computing device cluster. The computing device cluster includes at least one computing device. The computing device can be a server, such as a central server, an edge server, or a local server in a local data center. In some embodiments, the computing device can also be a terminal device such as a desktop computer, a laptop computer, or a smartphone.

[0289] As shown in Figure 12, the computing device cluster includes multiple computing devices 1000. The memory 1006 of the computing devices 1000 in the computing device cluster can store the same cross-chain system instructions for executing the cross-chain transaction method. Among them, at least one computing device stores the cross-chain system instructions for executing the cross-chain transaction method to implement the functions of the first blockchain network, at least one computing device stores the cross-chain system instructions for executing the cross-chain transaction method to implement the functions of the first blockchain network, and at least one computing device stores the cross-chain system instructions for executing the cross-chain transaction method.

[0290] In some possible implementations, one or more computing devices 1000 in the computing device cluster can also be used to execute some of the instructions of the cross-chain system for executing the cross-chain transaction method. In other words, the combination of one or more computing devices 1000 can jointly execute the instructions of the cross-chain system for executing the cross-chain transaction method.

[0291] As shown in Figure 13, the computing device cluster includes multiple computing devices 1000. The memory 1006 in the computing device 1000 in the computing device cluster may store the same cross-chain management system 900 for executing instructions of the cross-chain system construction method.

[0292] It should be noted that the memory 1006 in different computing devices 1000 in the computing device cluster can store different instructions for executing part of the functions of the cross-chain management system 900.

[0293] Figure 14 shows a possible implementation. As shown in Figure 14, two computing devices 1000A and 1000B are connected via a communication interface 1008. The memory in computing device 1000A stores instructions for executing the functions of deployment module 902. The memory in computing device 1000B stores instructions for executing the functions of registration module 904. In other words, the memories 1006 of computing devices 1000A and 1000B jointly store instructions for the cross-chain management system 900 to execute the cross-chain system construction method. Furthermore, computing device 1000A can also store instructions for the functions of state management module 906 and configuration module 908, and computing device 1000B can also store instructions for the functions of creation module 909.

[0294] The connection method between the computing device clusters shown in Figure 14 can be considered to take into account that the cross-chain system construction method provided in this application requires the deployment of cross-chain components for a large number of nodes. Therefore, it is considered to delegate the functions implemented by the deployment module 902 and the registration module 904 to different computing devices.

[0295] It should be understood that the functions of the computing device 1000A shown in FIG14 may also be completed by multiple computing devices 1000. Similarly, the functions of the computing device 1000B may also be completed by multiple computing devices 1000.

[0296] In some possible implementations, one or more computing devices in a computing device cluster may be connected via a network. The network may be a wide area network or a local area network, etc. FIG15 shows a possible implementation. As shown in FIG15 , two computing devices 1000C and 1000D are connected via a network. Specifically, the network is connected via a communication interface in each computing device. In this type of possible implementation, the memory 1006 in the computing device 1000C stores instructions for executing the functions of the deployment module 902. At the same time, the memory 1006 in the computing device 1000D stores instructions for executing the functions of the registration module 904. Furthermore, the computing device 1000A may also store instructions for the functions of the state management module 906 and the configuration module 908, and the computing device 1000B may also store instructions for the functions of the creation module 909.

[0297] It should be understood that the functions of the computing device 1000C shown in FIG15 may also be completed by multiple computing devices 1000. Similarly, the functions of the computing device 1000D may also be completed by multiple computing devices 1000.

[0298] The embodiment of the present application also provides a computer-readable storage medium. The computer-readable storage medium can be any available medium that can be stored by a computing device or a data storage device such as a data center that contains one or more available media. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid-state drive). The computer-readable storage medium includes instructions that instruct the computing device to execute the above-mentioned method for executing a cross-chain transaction in a cross-chain system. The embodiment of the present application also provides another computer-readable storage medium. The computer-readable storage medium includes instructions that instruct the computing device to execute the above-mentioned method for executing a cross-chain system construction in a cross-chain management system.

[0299] The present application also provides a computer program product containing instructions. This computer program product can be software or a program product containing instructions that can be run on a computing device or stored in any available medium. When the computer program product is run on at least one computing device, it causes the at least one computing device to execute the cross-chain transaction method described above. The present application also provides a computer program product containing instructions. When the computer program product is run on at least one computing device, it causes the at least one computing device to execute the cross-chain system construction method described above.

[0300] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the protection scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A cross-chain transaction method, characterized in that, Applied to a cross-chain system, the cross-chain system includes a first blockchain network, a second sub-blockchain network, and a third blockchain network. The second blockchain network and the third blockchain network are heterogeneous blockchain networks. Cross-chain components are respectively deployed in the first blockchain network, the second blockchain network, and the third blockchain network. The method includes: The cross-chain component of the first blockchain network obtains a cross-chain transaction request, which is used to request the execution of a cross-chain transaction from the second blockchain network to the third blockchain network; The cross-chain component of the first blockchain network performs identity verification and permission verification according to the cross-chain transaction request to obtain a verification result; When the verification result indicates that the verification is passed, when the cross-chain component of the first blockchain network reaches a consensus on the cross-chain transaction at the nodes of the first blockchain network, the transaction information of the cross-chain transaction is recorded in the ledger of the first blockchain network; The cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

2. The method according to claim 1, wherein The cross-chain components of the first blockchain network, the second blockchain network component, and the third blockchain network component form a synchronization network. The cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network, including: The cross-chain component of the first blockchain network broadcasts a notification message through the synchronization network. The notification message is used to notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

3. The method according to claim 2, characterized in that, The cross-chain components in the synchronization network perform message synchronization through the gossip protocol.

4. The method according to claim 1, wherein A direct connection channel is established between the cross-chain component of the first blockchain network and the cross-chain component of the third blockchain network; The cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network, including: The cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network through the direct connection channel.

5. The method according to any one of claims 1 to 4, characterized in that The method further includes: The cross-chain component of the first blockchain network identifies the transaction type of the cross-chain transaction; The cross-chain component of the first blockchain network records the transaction information of the cross-chain transaction in the ledger of the first blockchain network, including: When the transaction type is cross-chain write, the cross-chain component of the first blockchain network records the transaction information of the cross-chain transaction in the ledger of the first blockchain network.

6. The method according to any one of claims 1 to 5, characterized in that The method further includes: After the cross-chain component of the third blockchain network successfully records the transaction information of the cross-chain transaction in the ledger of the third blockchain network, it notifies the cross-chain component of the second blockchain network to record the transaction information of the cross-chain transaction in the ledger of the second blockchain network.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes: The cross-chain component of the first blockchain network receives the chain information and cross-chain access permission information of the second blockchain network, as well as the chain information and cross-chain access permission information of the third blockchain network, and records the chain information and cross-chain access permission information of the second blockchain network and the chain information and cross-chain access permission information of the third blockchain network into the ledger of the first blockchain network.

8. The method according to claim 7, wherein The method further includes: The cross-chain component of the first blockchain network detects the validity of the third blockchain network according to the chain information of the third blockchain network; The cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction into the ledger of the third blockchain network, including: When the third blockchain network is valid, the cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction into the ledger of the third blockchain network.

9. The method according to any one of claims 1 to 8, characterized in that, The cross-chain component of the first blockchain network obtains a cross-chain transaction request, including: The cross-chain component of the first blockchain network receives the cross-chain transaction request routed by the cross-chain component of the second blockchain network according to the routing address.

10. The method according to claim 9, wherein The cross-chain component includes an agent and a controller, and the agent encapsulates the interaction interfaces of the heterogeneous blockchain networks based on a general interaction protocol; The method further includes: The cross-chain component of the second blockchain network listens for the cross-chain transaction request through the general interaction protocol.

11. A method for constructing a cross-chain system, characterized in that, Applied to a cross-chain management system, the cross-chain management system is used to construct a cross-chain system, the cross-chain system includes a first blockchain network, a second sub-blockchain network, and a third sub-blockchain network, the second blockchain network and the third blockchain network are heterogeneous blockchain networks, and the method includes: Deploying cross-chain components on at least one node of the first blockchain network, and deploying the cross-chain components on at least one node of the second blockchain network and on at least one node of the third blockchain network; Registering the chain information and cross-chain access permission information of the second blockchain network in the first blockchain network, and registering the chain information and cross-chain access permission information of the third blockchain network in the first blockchain network, the chain information of the second blockchain network is used for the cross-chain component of the third blockchain network to discover the second blockchain network, and the chain information of the third blockchain network is used for the cross-chain component of the second blockchain network to discover the third blockchain network.

12. The method according to claim 11, characterized in that, The deploying the cross-chain component on at least one node of the third blockchain network includes: Downloading the cross-chain component from the first blockchain network; Adapting the cross-chain component to the third blockchain network; Deploying the adapted cross-chain component on at least one node of the third blockchain network.

13. The method according to claim 11 or 12, characterized in that, The method further includes: Checking the status of the cross-chain components deployed on at least one node in the first blockchain network; Determining the availability of the first blockchain network according to the number of nodes with normal status of the cross-chain components.

14. The method according to any one of claims 11 to 13, characterized in that The method further includes: Configure the first blockchain network as the main chain, and the main chain is used to relay cross-chain transactions between the second blockchain network and the third blockchain network.

15. The method according to any one of claims 11 to 14, characterized in that The method further includes: Create the second blockchain network using a first blockchain service, and create the third blockchain network using a second blockchain service. The second blockchain network and the third blockchain network are heterogeneous blockchain networks.

16. The method according to claim 15, wherein The first blockchain service and the second blockchain service provide standardized interfaces. Creating the second blockchain network using the first blockchain service and creating the second blockchain network using the second blockchain service include: Invoke the first blockchain service through the standardized interface to create the second blockchain network, and invoke the second blockchain service through the standardized interface to create the third blockchain network.

17. The method according to claim 15 or 16, characterized in that Creating the second blockchain network using the first blockchain service includes: Use the first blockchain service to create the second blockchain network that is independent of the organization of the first blockchain network.

18. A cross-chain system, characterized in that, The cross-chain system includes a first blockchain network, a second sub-blockchain network, and a third blockchain network. The second blockchain network and the third blockchain network are heterogeneous blockchain networks. Cross-chain components are respectively deployed on the first blockchain network, the second blockchain network, and the third blockchain network; The cross-chain component of the first blockchain network is used to obtain a cross-chain transaction request. The cross-chain transaction request is used to request the execution of a cross-chain transaction from the second blockchain network to the third blockchain network, and perform identity verification and permission verification according to the cross-chain transaction request to obtain a verification result; The cross-chain component of the first blockchain network is further used to, when the verification result indicates that the verification is passed and a consensus is reached on the cross-chain transaction at the nodes of the first blockchain network, record the transaction information of the cross-chain transaction in the ledger of the first blockchain network, Notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

19. The system according to claim 18, wherein The cross-chain component of the first blockchain network, the second blockchain network component, and the third blockchain network component form a synchronization network. The cross-chain component of the first blockchain network is specifically used for: Broadcast a notification message through the synchronization network. The notification message is used to notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

20. The system according to claim 18 or 19, characterized in that, The cross-chain components in the synchronization network perform message synchronization through a gossip protocol.

21. The system according to claim 18, wherein A direct connection channel is established between the cross-chain component of the first blockchain network and the cross-chain component of the third blockchain network; The cross-chain component of the first blockchain network is specifically used for: Notify the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network through the direct connection channel.

22. The system according to any one of claims 18 to 21, characterized in that, The cross-chain component of the first blockchain network is further used for: Identify the transaction type of the cross-chain transaction; The cross-chain component of the first blockchain network is specifically used for: When the transaction type is cross-chain write, record the transaction information of the cross-chain transaction in the ledger of the first blockchain network.

23. The system according to any one of claims 18 to 22, characterized in that The cross-chain component of the third blockchain network is specifically used for: When the transaction information of the cross-chain transaction is successfully recorded in the ledger of the third blockchain network, notify the cross-chain component of the second blockchain network to record the transaction information of the cross-chain transaction in the ledger of the second blockchain network.

24. The system according to any one of claims 18 to 23, characterized in that, The cross-chain component of the first blockchain network is further used for: Receive the chain information and cross-chain access permission information of the second blockchain network and the chain information and the cross-chain access permission information of the third blockchain network, and record the chain information and cross-chain access permission information of the second blockchain network and the chain information and the cross-chain access permission information of the third blockchain network in the ledger of the first blockchain network.

25. The system according to claim 24, wherein The cross-chain component of the first blockchain network is further used for: Detect the validity of the third blockchain network according to the chain information of the third blockchain network; The cross-chain component of the first blockchain network is specifically used for: When the third blockchain network is valid, the cross-chain component of the first blockchain network notifies the cross-chain component of the third blockchain network to record the transaction information of the cross-chain transaction in the ledger of the third blockchain network.

26. The system according to any one of claims 18 to 25, characterized in that, The cross-chain component of the first blockchain network is specifically used for: Receive the cross-chain transaction request routed by the cross-chain component of the second blockchain network according to the routing address.

27. The system according to claim 26, wherein The cross-chain component includes an agent and a controller, and the agent encapsulates the interaction interfaces of the heterogeneous blockchain networks based on the general interaction protocol; The cross-chain component of the second blockchain network is used for: Listen for the cross-chain transaction request through the general interaction protocol.

28. A cross-chain management system, characterized in that, The cross-chain management system is used to construct a cross-chain system, which includes a first blockchain network, a second sub-blockchain network, and a third sub-blockchain network. The second blockchain network and the third blockchain network are heterogeneous blockchain networks. The cross-chain management system includes: A deployment module, which is used to deploy cross-chain components on at least one node of the first blockchain network, and deploy the cross-chain components on at least one node of the second blockchain network, and deploy the cross-chain components on at least one node of the third blockchain network; A registration module, which is used to register the chain information and cross-chain access permission information of the second blockchain network in the first blockchain network, and register the chain information and cross-chain access permission information of the third blockchain network in the first blockchain network. The chain information of the second blockchain network is used for the cross-chain component of the third blockchain network to discover the second blockchain network, and the chain information of the third blockchain network Is used for the cross-chain component of the second blockchain network to discover the third blockchain network.

29. The system according to claim 28, wherein The deployment module is specifically used for: Download the cross-chain component from the first blockchain network; Adapt the cross-chain component to the third blockchain network; Deploy the adapted cross-chain component on at least one node of the third blockchain network.

30. The system according to claim 28 or 29, characterized in that, The system further includes: A status management module, configured to check the status of cross-chain components deployed on at least one node in the first blockchain network, and determine the availability of the first blockchain network according to the number of nodes with normal status of the cross-chain components.

31. The system according to any one of claims 28 to 30, characterized in that, The system further includes: A configuration module, configured to configure the first blockchain network as a main chain, and the main chain is used to relay cross-chain transactions between the second blockchain network and the third blockchain network.

32. The system according to any one of claims 28 to 31, characterized in that, The system further includes: A creation module, configured to create the second blockchain network using a first blockchain service and create the third blockchain network using a second blockchain service, and the second blockchain network and the third blockchain network are heterogeneous blockchain networks.

33. The system according to claim 32, characterized in that, The first blockchain service and the second blockchain service provide standardized interfaces, and specifically, the creation module is configured to: Call the first blockchain service through the standardized interface to create the second blockchain network, and call the second blockchain service through the standardized interface to create the third blockchain network.

34. The system according to claim 32 or 33, characterized in that, Specifically, the creation module is configured to: Use the first blockchain service to create the second blockchain network that is independent of the organization of the first blockchain network.

35. A cluster of computing devices, characterized in that, The computing device cluster includes at least one computing device, the at least one computing device includes at least one processor and at least one memory, and computer-readable instructions are stored in the at least one memory; the at least one processor executes the computer-readable instructions to cause the computing device cluster to execute the method according to any one of claims 1 to 17.

36. A computer-readable storage medium, characterized in that, Including computer-readable instructions; the computer-readable instructions are used to implement the method according to any one of claims 1 to 17.

37. A computer program product, characterized in that, Including computer-readable instructions; the computer-readable instructions are used to implement the method according to any one of claims 1 to 17.

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