Cross-chain resource transfer method, system and device in cross-chain system

Abstract

The invention provides a cross-chain resource transfer method, system and device in a cross-chain system. The cross-chain system comprises a first block chain and a second block chain. A first resource contract, a first transition contract and a first cross-chain contract are deployed in the first block chain; a second resource contract, a second transition contract and a second cross-chain contract are deployed in the second block chain; the method is executed by a node of a first block chain. The method comprises the following steps: receiving a first transaction calling a first resource contract; the first transaction instructs to transfer a first resource from a first account of the first block chain to a second account of the second block chain; based on the first transaction, transferring the first resource from the first account to the first transition contract, calling a sending interface of the first cross-chain contract through the first transition contract, and transmitting a cross-chain message to the second block chain; the cross-chain message is used for indicating that the first resource is transferred to the second account through the second resource contract and the second transition contract.

Description

Technical Field

[0001] One or more embodiments of this specification relate to the field of blockchain technology, and in particular, to a method, system, and device for cross-chain resource transfer in a cross-chain system. Background Art

[0002] Blockchain is a new application model of computer technologies such as distributed data storage, peer-to-peer transmission, consensus mechanism, encryption algorithm, etc. In the blockchain, data blocks are combined into a chain data structure in a sequential manner according to time order, and cryptography is used to ensure that the data blocks cannot be tampered with or forged. Due to the characteristics of blockchain such as decentralization, information cannot be tampered with, and autonomy, blockchain has also received more and more attention and application. At present, a solution for cross-chain transfer of resources in a cross-chain system is needed. Summary of the invention

[0003] One or more embodiments of this specification provide a method, system, and device for cross-chain resource transfer in a cross-chain system.

[0004] According to a first aspect, a method for cross-chain resource transfer in a cross-chain system is provided, wherein the cross-chain system includes a first blockchain and a second blockchain; the first blockchain is deployed with a first resource contract, a first transition contract and a first cross-chain contract; the second blockchain is deployed with a second resource contract, a second transition contract and a second cross-chain contract; the method is executed by a node of the first blockchain; the method includes:

[0005] Receiving a first transaction that calls the first resource contract; the first transaction indicates a transfer of a first resource from a first account on the first blockchain to a second account on the second blockchain;

[0006] Based on the first transaction, the first resource is transferred from the first account to the first transition contract, and the sending interface of the first cross-chain contract is called through the first transition contract to transmit a cross-chain message to the second blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract.

[0007] According to a second aspect, a method for cross-chain resource transfer in a cross-chain system is provided, wherein the cross-chain system includes a first blockchain and a second blockchain; a second resource contract, a second transition contract and a second cross-chain contract are deployed in the second blockchain; the method is executed by a node of the second blockchain; the method includes:

[0008] receiving a cross-chain transfer transaction that calls the second cross-chain contract; the cross-chain transfer transaction includes a cross-chain message from the first blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract;

[0009] Run the second cross-chain contract, trigger the second transition contract to call the second resource contract to update the resources in the second account based on the cross-chain message, so as to perform a cross-chain transfer operation.

[0010] According to a third aspect, a cross-chain system is provided, the cross-chain system comprising a first blockchain and a second blockchain; the first blockchain is deployed with a first resource contract, a first transition contract and a first cross-chain contract; the second blockchain is deployed with a second resource contract, a second transition contract and a second cross-chain contract;

[0011] The node of the first blockchain is used to receive a first transaction that calls the first resource contract; the first transaction indicates the transfer of the first resource from the first account of the first blockchain to the second account of the second blockchain; based on the first transaction, the first resource is transferred from the first account to the first transition contract, and the sending interface of the first cross-chain contract is called through the first transition contract to transmit a cross-chain message to the second blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract;

[0012] The node of the second blockchain is used to perform a cross-chain transfer operation based on the cross-chain message.

[0013] According to a fourth aspect, a device for cross-chain resource transfer in a cross-chain system is provided, the cross-chain system comprising a first blockchain and a second blockchain; the first blockchain is deployed with a first resource contract, a first transition contract and a first cross-chain contract; the second blockchain is deployed with a second resource contract, a second transition contract and a second cross-chain contract; the device is deployed on a node of the first blockchain; the device comprises:

[0014] A receiving module, configured to receive a first transaction for invoking the first resource contract; the first transaction indicates a transfer of a first resource from a first account of the first blockchain to a second account of the second blockchain;

[0015] An execution module is used to transfer the first resource from the first account to the first transition contract based on the first transaction, and call the sending interface of the first cross-chain contract through the first transition contract to transmit a cross-chain message to the second blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract.

[0016] According to a fifth aspect, a device for cross-chain resource transfer in a cross-chain system is provided, wherein the cross-chain system includes a first blockchain and a second blockchain; a second resource contract, a second transition contract and a second cross-chain contract are deployed in the second blockchain; the device is deployed on a node of the second blockchain for execution; and the method includes:

[0017] A receiving module, configured to receive a cross-chain transfer transaction that calls the second cross-chain contract; the cross-chain transfer transaction includes a cross-chain message from the first blockchain; the cross-chain message is used to indicate that the first resource is transferred to the second account through the second resource contract and the second transition contract;

[0018] The transfer module is used to run the second cross-chain contract, trigger the second transition contract to call the second resource contract to update the resources in the second account based on the cross-chain message, so as to perform a cross-chain transfer operation.

[0019] According to a sixth aspect, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the method described in any one of the first aspect or the second aspect is implemented.

[0020] According to the seventh aspect, a computing device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method described in any one of the first aspect or the second aspect is implemented.

[0021] The technical solutions provided by the embodiments of this specification may have the following beneficial effects:

[0022] The method and device for cross-chain resource transfer in a cross-chain system provided by the embodiments of this specification are implemented by deploying a first resource contract, a first transition contract and a first cross-chain contract in the first blockchain in the cross-chain system, and deploying a second resource contract, a second transition contract and a second cross-chain contract in the second blockchain. After receiving a first transaction indicating the transfer of a first resource from a first account of the first blockchain to a second account of the second blockchain, the node of the first blockchain transfers the first resource from the first account to the first transition contract based on the first transaction, and calls the sending interface of the first cross-chain contract through the first transition contract to transmit a cross-chain message to the second blockchain, the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract, and the node of the second blockchain performs a cross-chain transfer operation based on the cross-chain message. Thus, digital resources can be managed and cross-chain transfers can be performed through multiple smart contracts deployed in the blockchain system.

[0023] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 This is an architecture diagram of a blockchain system shown in this specification according to an exemplary embodiment;

[0026] Figure 2 This is an interactive flow chart of a method for transferring resources across chains in a cross-chain system according to an exemplary embodiment of this specification;

[0027] Figure 3a is a message body schematic diagram of a cross-chain message according to an exemplary embodiment of this specification;

[0028] Figure 3b This is a schematic diagram of a scenario of cross-chain resource transfer in a cross-chain system according to an exemplary embodiment of this specification;

[0029] Figure 3c This is a schematic diagram of another cross-chain resource transfer scenario in a cross-chain system according to an exemplary embodiment of this specification; Figure 4 is a block diagram of a cross-chain resource transfer device in a cross-chain system according to an exemplary embodiment of the present specification; Figure 5 It is a block diagram of another cross-chain resource transfer device in a cross-chain system shown in this specification according to an exemplary embodiment. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0031] Figure 1 FIG. 1 shows an architecture diagram of a blockchain system in an embodiment. Figure 1 As shown, the blockchain system includes N nodes. Figure 1Nodes 1 to 8 are schematically shown in FIG. The lines between the nodes schematically represent the connection between the nodes, which is used to transmit data between the nodes. These nodes can store the full amount of ledgers, that is, store the status of all blocks and all accounts. Among them, each node in the blockchain system can generate the same state in the blockchain system by executing the same transaction, and each node in the blockchain system can store the same state database.

[0032] Transactions in the blockchain field can refer to task units executed and recorded in the blockchain system. Transactions usually include a send field (From), a receive field (To), and a data field (Data). Among them, in the case of a transfer transaction, the From field indicates the account address that initiates the transaction (i.e., initiates a transfer task to another account), the To field indicates the account address that receives the transaction (i.e., receives the transfer), and the Data field includes the transfer amount.

[0033] The blockchain system can provide the function of smart contracts. Smart contracts on the blockchain system are contracts that can be triggered and executed by transactions on the blockchain system. Smart contracts can be defined in the form of code. Calling a smart contract in the blockchain system is to initiate a transaction pointing to the smart contract address, so that each node in the blockchain system can run the smart contract code in a distributed manner.

[0034] In the scenario of deploying a contract, for example, Bob sends a transaction containing information about creating a smart contract (i.e. deploying a contract) to Figure 1 In the blockchain system shown, the data field of the transaction includes the code of the contract to be created (such as bytecode or machine code), and the to field of the transaction is empty to indicate that the transaction is used to deploy the contract. After the nodes reach an agreement through the consensus mechanism, the contract address "0x6f8ae93..." of the contract is determined, and each node adds a contract account corresponding to the contract address of the smart contract in the state database, allocates the state storage corresponding to the contract account, and stores the contract code, and saves the hash value of the contract code in the state storage of the contract, so that the contract is successfully created.

[0035] In the scenario of calling a contract, for example, Bob sends a transaction for calling a smart contract to Figure 1 In the blockchain system shown, the from field of the transaction is the address of the account of the transaction initiator (i.e., Bob), the to field is the above-mentioned "0x6f8ae93...", that is, the address of the smart contract being called, and the data field of the transaction includes the method and parameters for calling the smart contract. After the blockchain system reaches a consensus on the transaction, each node in the blockchain system can execute the transaction separately, thereby executing the contract separately, and updating the status database based on the execution of the contract.

[0036] At present, with the continuous development of the blockchain industry, more and more organizations or institutions use blockchain systems to carry business capabilities, many of which involve digital resources, and the expansion of business has brought about the need for cross-chain interaction, thus promoting the generation and improvement of cross-chain systems. A cross-chain system involving digital resources can include multiple blockchain systems, and digital resources can be transferred between different blockchain systems, thereby enhancing the liquidity of digital resources.

[0037] To this end, the embodiments of this specification provide a cross-chain transfer solution in a cross-chain system, which can manage digital resources and transfer cross-chain accounts through multiple smart contracts deployed in the blockchain system. When transferring digital resources from one blockchain to another, the uniqueness of the digital resources and the unchanged properties can be guaranteed, and the cross-chain transfer of digital resources maintains atomicity and consistency.

[0038] The solution provided in this specification will be described in detail below in conjunction with specific embodiments.

[0039] like Figure 2 As shown, Figure 2 This is an interactive flow chart of a cross-chain resource transfer method in a cross-chain system according to an exemplary embodiment. The cross-chain system includes a first blockchain and a second blockchain. The first blockchain and the second blockchain each include multiple nodes, and resource contracts, transition contracts and cross-chain contracts are deployed in the first blockchain and the second blockchain. For example, resource contracts C11, transition contracts C12 and cross-chain contracts C13 are deployed in the first blockchain, and resource contracts C21, transition contracts C22 and cross-chain contracts C23 are deployed in the second blockchain. The method includes the following steps:

[0040] In step 201, the user device sends a transaction TX1 to the node of the first blockchain to call the resource contract C11, and in step 203, the node of the first blockchain transfers the resource Z from account A to the transition contract C12 based on the transaction TX1, and calls the sending interface of the cross-chain contract C13 through the transition contract C12 to transmit the cross-chain message X to the node of the second blockchain.

[0041] Among them, resource contracts can be used to manage digital resources, store the balances of digital resources of multiple different accounts, and handle transfer transactions, etc. Cross-chain contracts can be used to provide a sending and receiving interface for cross-chain messages to send cross-chain messages to other blockchains, or receive cross-chain messages from other blockchains. Transition contracts can be used to maintain cross-chain reference information, which can include, for example, the association between the contract address of the resource contract deployed in this blockchain and the contract address of the same type of resource contract deployed in other blockchains, the cross-chain routing table, the contract address of the transition contract deployed in other blockchains, and record the data of each cross-chain transaction, etc. The sending interface of the cross-chain contract can also be called to send or receive cross-chain messages for the resource contract.

[0042] In this embodiment, taking the transfer of resource Z from account A to account B as an example, the user can send transaction TX1 to the node of the first blockchain through the user device, and transaction TX1 calls the resource contract C11. Transaction TX1 can indicate the transfer of resource Z from account A of the first blockchain to account B of the second blockchain. The node of the first blockchain can receive transaction TX1, and based on transaction TX1, transmit cross-chain message X to the node of the second blockchain. Among them, resource Z can be a digital resource, for example, it can be a non-homogeneous digital resource.

[0043] Specifically, transaction TX1 may include cross-chain transfer data, which may include the account identifier of account A that transfers out resources, the account identifier of account B that transfers in resources, the blockchain address of the second blockchain where account B is located, the contract address of the transition contract C22 deployed in the second blockchain, and the resource data of the resource Z to be transferred. The node of the first blockchain may first call the transfer interface in the resource contract C11 based on transaction TX1 to transfer resource Z from account A to the account of transition contract C12 (i.e., in the contract state of resource contract C11, resource Z is eliminated from account A, and in the contract state of transition contract C12, resource Z is added), and trigger the execution of the cross-chain process in transition contract C12. It should be noted that after transferring resource Z to the account of transition contract C12, resource Z needs to be locked so that resource Z always remains locked in the account of transition contract C12.

[0044] Next, the cross-chain process in the transition contract C12 is executed. The cross-chain transfer data can be obtained from the transaction TX1, and the cross-chain reference information can be obtained from the contract status of the transition contract C12. For example, the cross-chain reference information can include the binding relationship between the contract address A11 of the resource contract C11 and the contract address A21 of the resource contract C21, the cross-chain routing table, and the contract address A22 of the transition contract C22. Then, based on the cross-chain transfer data and the cross-chain reference information, the message content M is generated. Specifically, according to the cross-chain transfer data, the contract address A21 of the resource contract C21, the contract address A22 of the transition contract C22, and the routing information required to transfer the resource Z can be found from the cross-chain reference information, and then the message content M is generated based on the above information. Finally, by calling the sending interface of the cross-chain contract C13, a cross-chain message X containing the message content M is generated, and the operation of transmitting the cross-chain message X to the second blockchain is executed. In addition, the cross-chain event can also be recorded in the cross-chain event history data, where the cross-chain event history data is stored in the contract state of the cross-chain contract C13.

[0045] Figure 3a A schematic diagram of the message body of a cross-chain message is shown, such as Figure 3a As shown, taking the above embodiment of transferring resource Z from account A to account B as an example, the message body of cross-chain message X may include the following fields: version, sender_contract, target_domain, receiver_contract, sequence, and payload. Among them, the version field is used to record the version number of the message body of cross-chain message X; the sender_contract field is used to record the contract address A12 of the transition contract C12 in the first blockchain; the target_domain field is used to record the ID of the second blockchain in the cross-chain system (the cross-chain system configures a unique domain name for each blockchain as the ID of the blockchain); the receiver_contract field is used to record the contract address A22 of the transition contract C22 in the second blockchain; the sequence field is used to record the sequence number of the cross-chain message X (a message with a smaller sequence number is uploaded to the chain before a message with a larger sequence number), and the payload field is used to record the message content M.

[0046] The message content M may further include the following fields: sender_asset, receiver_asset, asset_type, raw_asset_info, status, error_msg, extension. The sender_asset field is used to record the contract address A11 of the resource contract C11 in the first blockchain; the receiver_asset field is used to record the contract address A12 of the resource contract C12 in the second blockchain; the asset_type field is used to record the type of resource Z; the status field is used to record the status of the asset cross-chain, corresponding to the asset cross-chain result, wherein, for example, status may indicate the sending status, the success status and the failure status, if the status indicates the sending status, it means that the cross-chain message X has been sent, if the status indicates the success status, it means that the cross-chain transfer is successful, if the status indicates the failure status, it means that the cross-chain transfer fails); the error_msg field is used to record the message content after the cross-chain transfer operation fails; the extension field is used to record the extended information, which can save additional resource attributes; the raw_asset_info field is used to record the resource transfer information. Resource transfer information may include the following fields: sender_account, token_ids, amounts, receiver_account. The sender_account field is used to record the account address of account A; the token_ids field is used to record the identifier of resource Z; the amounts field is used to record the amount of resource Z to be transferred; and the receiver_account field is used to record the account address of account B.

[0047] In this embodiment, when the node of the first blockchain performs the operation of transmitting the cross-chain message X to the second blockchain, the node of the first blockchain can directly send the transaction TX2 to the second blockchain, and the transaction TX2 includes the cross-chain message X. The node of the first blockchain can also send the cross-chain message X to other system devices, and the other system devices can send the transaction TX2 including the cross-chain message X to the second blockchain. For example, the cross-chain system can include a relay system and an endorsement system. The relay system can be used to transmit cross-chain messages between different blockchains, and the endorsement system can be used to verify the legitimacy of the cross-chain message and provide an endorsement certificate. Specifically, the endorsement system can obtain the block data of the first blockchain, and according to the block data of the first blockchain, find the cross-chain transfer event corresponding to the cross-chain message X in the block n with a block height of n. Obtain the consensus node signature and Merkle proof p corresponding to block n. Verify the proof p carried by the cross-chain message X. If the proof p is the same as the value in the block header, the endorsement system generates an endorsement proof. Since the endorsement system is used for verification, a large number of redundant signatures are not required, the number of signatures for cross-chain verification is reduced, and the system performance is improved.

[0048] like Figure 3b As shown, in some implementations, the node of the first blockchain can first send the cross-chain message X to the endorsement system through the relay system, and the endorsement system verifies the legitimacy of the cross-chain message X and generates signature data for proof. Then, the endorsement system can send the verification result and signature data to the relay system, and the relay system sends the transaction TX2 to the second blockchain, and the transaction TX2 carries the cross-chain message X, the verification result and the signature data.

[0049] like Figure 3c As shown, in other implementations, the cross-chain system may also include a third blockchain for auditing and storing evidence, and the third blockchain is deployed with resource contract C31, transition contract C32 and cross-chain contract C33. The node of the first blockchain can first send the cross-chain message X to the endorsement system through the relay system, and the endorsement system verifies the legitimacy of the cross-chain message X and generates signature data for proof. Then, the endorsement system can send the verification result and signature data to the relay system, and the relay system sends transaction TX3 to the third blockchain, and transaction TX3 carries cross-chain message X, verification result and signature data. After receiving transaction TX3, the node of the third blockchain can call resource contract C31, transition contract C32 and cross-chain contract C33, parse transaction TX3, obtain cross-chain message X, verification result and signature data, and audit and store evidence based on cross-chain message X, verification result and signature data. Then, the node of the third blockchain sends the cross-chain message X, verification result and signature data to the relay system, instructing the relay system to send transaction TX2 to the second blockchain, and transaction TX2 carries the cross-chain message X, verification result and signature data.

[0050] In step 205, a transaction TX2 including a cross-chain message X is obtained, and in step 207, the cross-chain contract C23 is run to trigger the transition contract C22 to call the resource contract C21 based on the cross-chain message X to update the resources in account B.

[0051] In this embodiment, the node of the second blockchain can receive the transaction TX2 carrying the cross-chain message X, the verification result and the signature data through the receiving interface of the cross-chain contract C23, and verify the verification result and the signature data through the cross-chain contract C23. After the verification is passed, the cross-chain message X can be obtained, the contract address A22 of the transition contract C22 in the second blockchain can be determined according to the cross-chain message X, and the transition contract C22 can be called according to the contract address A22. By calling the transition contract C22, the transfer information such as the contract address A11 of the resource contract C11 of the first blockchain, the contract address A21 of the resource contract C21 of the second blockchain, the account address of account B, the type of resource Z, and the amount of resources in the cross-chain message X can be extracted. Based on the above transfer information, by calling the interface of the resource contract C21, the resources of account B are updated using resource Z.

[0052] Specifically, some digital resources in a locked state can be stored in the contract state of the transition contract C22. These digital resources in a locked state may be pre-existing in the contract state of the transition contract C22, or may be transferred from the resource contract C21 through some transactions. This embodiment does not limit this aspect. In the process of updating the resources of Account B, it can be determined whether resource Z is stored in the contract state of the transition contract C22 based on the above transfer information. If resource Z does not exist, the transition contract C22 can instruct the resource contract C21 to cast resource Z, and add the cast resource Z to Account B in the contract state of the resource contract C21, thereby completing the update of Account B. If there is a resource Z in a locked state, the transition contract C22 unlocks the resource Z in the locked state, and adds the unlocked resource Z to Account B in the contract state of the resource contract C21, thereby completing the update of Account B.

[0053] In step 209, the node of the second blockchain returns the operation result of the cross-chain transfer operation to the first blockchain, and in step 210, calls the transition contract C22 to process the operation result.

[0054] In this embodiment, after completing the update of account B, the transition contract C22 can generate a return message, which may include but is not limited to the contract address A12 of the transition contract C12 of the first blockchain, the contract address A22 of the transition contract C22 of the second blockchain, the contract address A11 of the resource contract C11 of the first blockchain, the contract address A21 of the resource contract C21 of the second blockchain, the account address of account A, the account address of account B, the category of resource Z, the amount of resource Z to be transferred, and the operation result of the cross-chain transfer operation (i.e., whether the cross-chain transfer operation is successful). The node of the second blockchain can return the above return message to the node of the first blockchain by calling the sending interface of the cross-chain contract C23.

[0055] The node of the first blockchain receives the return message through the receiving interface of the cross-chain contract C13. And calls the transition contract C12 to process the operation result in the return message. Specifically, if the operation result indicates that the cross-chain transfer operation is successful, the transition contract C12 can record the operation result in the cross-chain event history data for evidence storage. If the operation result indicates that the cross-chain transfer operation fails, the resource Z in the locked state in the contract state of the transition contract C12 can be unlocked, and the unlocked resource Z is added to the account A in the contract state of the resource contract C11, and the resource Z in the contract state of the transition contract is eliminated.

[0056] The above-mentioned embodiments of this specification provide a method for cross-chain resource transfer in a cross-chain system, by deploying a first resource contract, a first transition contract and a first cross-chain contract in the first blockchain in the cross-chain system, and deploying a second resource contract, a second transition contract and a second cross-chain contract in the second blockchain. After receiving a first transaction indicating the transfer of a first resource from a first account of the first blockchain to a second account of the second blockchain, the node of the first blockchain transfers the first resource from the first account to the first transition contract based on the first transaction, and calls the sending interface of the first cross-chain contract through the first transition contract to transmit a cross-chain message to the second blockchain, the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract, and the node of the second blockchain performs a cross-chain transfer operation based on the cross-chain message. Thus, it is possible to manage digital resources and transfer cross-chain accounts through multiple smart contracts deployed in the blockchain system.

[0057] It should be noted that although the operations of the methods of the embodiments of this specification are described in a specific order in the above embodiments, this does not require or imply that the operations must be performed in this specific order, or that all the operations shown must be performed to achieve the desired results. On the contrary, the steps depicted in the flowchart can change the order of execution. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be decomposed into multiple steps for execution.

[0058] Corresponding to the aforementioned method embodiment of cross-chain resource transfer in a cross-chain system, this specification also provides an embodiment of an apparatus for cross-chain resource transfer in a cross-chain system.

[0059] like Figure 4 As shown, Figure 4 This is a block diagram of a device for transferring resources across chains in a cross-chain system according to an exemplary embodiment of the present specification. The cross-chain system includes a first blockchain and a second blockchain. The first blockchain is deployed with a first resource contract, a first transition contract and a first cross-chain contract. The second blockchain is deployed with a second resource contract, a second transition contract and a second cross-chain contract. The device is deployed on a node of the first blockchain. The device may include: a receiving module 401 and an execution module 402.

[0060] Among them, the receiving module 401 is used to receive a first transaction that calls the first resource contract; the first transaction indicates the transfer of a first resource from a first account in the first blockchain to a second account in the second blockchain.

[0061] An execution module 402 is used to transfer the first resource from the first account to the first transition contract based on the first transaction, and call the sending interface of the first cross-chain contract through the first transition contract to transmit a cross-chain message to the second blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract.

[0062] In some embodiments, the execution module 402 transfers the first resource from the first account to the first transition contract in the following manner: in the contract state of the first resource contract, the first resource is eliminated from the first account; in the contract state of the first transition contract, the first resource is added to put the first resource in a locked state.

[0063] In other embodiments, the first transaction includes cross-chain transfer data; the cross-chain transfer data includes information of the first resource, account information of the second account, and information of the second blockchain; wherein the contract state of the first transition contract stores cross-chain reference information; the cross-chain reference information includes a binding relationship between accounts in the first resource contract and the second resource contract, routing information for transferring the first resource to the second blockchain, and a contract address of the second transition contract deployed in the second blockchain.

[0064] In some other embodiments, the execution module 402 calls the sending interface of the first cross-chain contract through the first transition contract in the following manner: obtaining the cross-chain reference information from the contract state of the first transition contract; executing the sending interface of the first cross-chain contract based on the cross-chain transfer data and the cross-chain reference information, generating a cross-chain message to transmit the cross-chain message to the second blockchain; and recording the cross-chain event in the cross-chain event history data.

[0065] In some other embodiments, the cross-chain system also includes a relay system and an endorsement system; wherein the execution module 402 transmits a cross-chain message to the second blockchain in the following manner: instructing the relay node in the relay system to request the endorsement system to perform cross-chain transfer verification, so that the endorsement system performs the cross-chain transfer verification, and after the cross-chain transfer verification is passed, sending the verification result and signature data to the relay node, and the relay node requests the second blockchain to perform a cross-chain transfer based on the cross-chain message, the verification result and the signature data.

[0066] In other embodiments, the relay node requests the second blockchain to perform a cross-chain transfer based on the cross-chain message, the verification result and the signature data in the following manner: sending a cross-chain transfer transaction to the second blockchain; the cross-chain transfer transaction includes the cross-chain message, the verification result and the signature data.

[0067] In some other embodiments, the cross-chain system also includes a third blockchain; a third resource contract, a third cross-chain contract and a third system contract are deployed in the third blockchain; wherein the relay node requests the second blockchain to perform a cross-chain transfer based on the cross-chain message, the verification result and the signature data in the following manner: sending a second transaction to the third blockchain; the second transaction includes the cross-chain message, the verification result and the signature data; enabling the node of the third blockchain to perform audit and evidence based on the second transaction, through the third resource contract, the third cross-chain contract and the third system contract, based on the cross-chain message, the verification result and the signature data; under the instruction of the node of the third blockchain, sending a cross-chain transfer transaction to the node of the second blockchain; the cross-chain transfer transaction includes at least the cross-chain message.

[0068] In some other implementations, the device may further include: an acquisition module and a processing module (not shown in the figure).

[0069] The acquisition module is used to obtain the operation result of the cross-chain transfer operation returned by the second blockchain;

[0070] A processing module is used to receive the operation result through the receiving interface of the first cross-chain contract, and call the first transition contract to process the operation result; if the operation result indicates that the cross-chain transfer operation fails, unlock the first resource in a locked state from the contract state of the first transition contract, add the first resource to the second account in the contract state of the first resource contract, and eliminate the first resource in the contract state of the first transition contract.

[0071] like Figure 5 As shown, Figure 5 This is a block diagram of a device for transferring resources across chains in another cross-chain system according to an exemplary embodiment of the present specification, wherein the cross-chain system includes a first blockchain and a second blockchain. A second resource contract, a second transition contract, and a second cross-chain contract are deployed in the second blockchain, and the device is deployed on a node of the second blockchain. The device may include: a receiving module 501 and a transfer module 502.

[0072] The receiving module 501 is used to receive a cross-chain transfer transaction that calls the second cross-chain contract; the cross-chain transfer transaction includes a cross-chain message from the first blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract.

[0073] The transfer module 502 is used to run the second cross-chain contract, trigger the second transition contract to call the second resource contract to update the resources in the second account based on the cross-chain message, so as to perform a cross-chain transfer operation.

[0074] In other embodiments, the transfer module 502 calls the second resource contract to update the resources in the second account based on the cross-chain message in the following manner: based on the cross-chain message, determine whether the first resource exists in the contract state of the second transition contract; if the first resource does not exist, instruct the second resource contract to mint the first resource, and add the first resource to the second account in the contract state of the second resource contract; if there is a locked first resource, unlock the locked first resource, and add the unlocked first resource to the second account in the contract state of the second resource contract.

[0075] In some other embodiments, the device may further include: a return module (not shown in the figure).

[0076] Among them, the return module is used to return the operation result of the cross-chain transfer operation to the node of the first blockchain, so that the node of the first blockchain receives the operation result through the receiving interface of the first cross-chain contract, and calls the first transition contract to process the operation result.

[0077] It should be understood that the above device can be pre-set in the blockchain node, or loaded into the blockchain node by downloading, etc. The corresponding modules in the above device can cooperate with the modules in the blockchain node to implement the cross-chain resource transfer solution in the cross-chain system.

[0078] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can refer to the partial description of the method embodiments. The device embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of one or more embodiments of the present specification. A person of ordinary skill in the art can understand and implement them without creative work.

[0079] One or more embodiments of the present specification also provide a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 2 A method for cross-chain resource transfer in a cross-chain system provided in any embodiment.

[0080] One or more embodiments of the present specification further provide a computing device, including a memory and a processor, wherein the memory stores an executable code, and when the processor executes the executable code, the above-mentioned Figure 2 A method for cross-chain resource transfer in a cross-chain system provided in any embodiment.

[0081] In the 1990s, improvements to a technology could be clearly distinguished as hardware improvements (for example, improvements to the circuit structure of diodes, transistors, switches, etc.) or software improvements (improvements to the method flow). However, with the development of technology, many improvements to the method flow today can be regarded as direct improvements to the hardware circuit structure. Designers almost always obtain the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that an improvement in a method flow cannot be implemented using a hardware entity module. For example, a programmable logic device (PLD) (such as a field programmable gate array (FPGA)) is such an integrated circuit whose logical function is determined by the user's programming of the device. Designers can "integrate" a digital system on a PLD by programming it themselves, without having to ask a chip manufacturer to design and produce a dedicated integrated circuit chip. Moreover, nowadays, instead of manually making integrated circuit chips, this kind of programming is mostly implemented by "logic compiler" software, which is similar to the software compiler used when developing and writing programs, and the original code before compilation must also be written in a specific programming language, which is called hardware description language (HDL). There is not only one HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should also know that it is only necessary to program the method flow slightly in the above-mentioned hardware description languages ​​and program it into the integrated circuit, and then it is easy to obtain the hardware circuit that implements the logic method flow.

[0082] The controller can be implemented in any appropriate manner, for example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing a computer-readable program code (such as software or firmware) that can be executed by the (micro)processor, a logic gate, a switch, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in a purely computer-readable program code manner, the controller can be implemented in the form of a logic gate, a switch, an application-specific integrated circuit, a programmable logic controller, and an embedded microcontroller by logically programming the method steps. Therefore, this controller can be considered as a hardware component, and the devices included therein for implementing various functions can also be regarded as structures within the hardware component. Or even, the devices for implementing various functions can be regarded as both software modules for implementing the method and structures within the hardware component.

[0083] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a server system. Of course, the present application does not exclude that with the development of computer technology in the future, the computer that implements the functions of the above embodiments may be, for example, a personal computer, a laptop computer, a vehicle-mounted human-computer interaction device, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0084] Although one or more embodiments of the present specification provide method operation steps as described in the embodiments or flow charts, more or less operation steps may be included based on conventional or non-creative means. The order of steps listed in the embodiments is only one way of executing the order of many steps, and does not represent the only execution order. When the device or terminal product in practice is executed, it can be executed in sequence or in parallel according to the method shown in the embodiments or the drawings (for example, a parallel processor or a multi-threaded processing environment, or even a distributed data processing environment). The term "include", "include" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, product or equipment including a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such a process, method, product or equipment. In the absence of more restrictions, it is not excluded that there are other identical or equivalent elements in the process, method, product or equipment including the elements. For example, if the words first, second, etc. are used to represent the name, they do not represent any specific order.

[0085] For the convenience of description, the above devices are described in various modules according to their functions. Of course, when implementing one or more of the present specification, the functions of each module can be implemented in the same or more software and / or hardware, or the module implementing the same function can be implemented by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0086] The present invention is described with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0087] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0088] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0089] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0090] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0091] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage, graphene storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0092] It should be understood by those skilled in the art that one or more embodiments of the present specification may be provided as a method, system or computer program product. Therefore, one or more embodiments of the present specification may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, one or more embodiments of the present specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0093] One or more embodiments of this specification may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. One or more embodiments of this specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0094] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. In the description of this specification, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this specification. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0095] The above description is only an example of one or more embodiments of this specification and is not intended to limit one or more embodiments of this specification. For those skilled in the art, one or more embodiments of this specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification shall be included in the scope of the claims.

Claims

1. A method for cross-chain resource transfer in a cross-chain system, the cross-chain system comprising a first blockchain and a second blockchain; the first blockchain is deployed with a first resource contract, a first transition contract and a first cross-chain contract; the second blockchain is deployed with a second resource contract, a second transition contract and a second cross-chain contract; The method is performed by a node of the first blockchain; the method includes: Receiving a first transaction that calls the first resource contract; the first transaction indicates a transfer of a first resource from a first account of the first blockchain to a second account of the second blockchain; Based on the first transaction, the first resource is transferred from the first account to the first transition contract, and the sending interface of the first cross-chain contract is called through the first transition contract to transmit a cross-chain message to the second blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract.

2. The method according to claim 1, wherein: The transferring the first resource from the first account to the first transition contract includes: In the contract state of the first resource contract, eliminating the first resource from the first account; In the contract state of the first transition contract, the first resource is added to put the first resource in a locked state.

3. The method according to claim 1, wherein: The first transaction includes cross-chain transfer data; the cross-chain transfer data includes information about the first resource, account information about the second account, and information about the second blockchain; Among them, cross-chain reference information is stored in the contract state of the first transition contract; the cross-chain reference information includes the binding relationship between the accounts in the first resource contract and the second resource contract, routing information for transferring the first resource to the second blockchain, and the contract address of the second transition contract deployed in the second blockchain.

4. The method according to claim 3, wherein: The calling the sending interface of the first cross-chain contract through the first transition contract includes: Acquire the cross-chain reference information from the contract state of the first transition contract; Based on the cross-chain transfer data and the cross-chain reference information, execute the sending interface of the first cross-chain contract to generate a cross-chain message to transmit the cross-chain message to the second blockchain; and Record cross-chain events in cross-chain event history data.

5. The method according to claim 1, wherein: The cross-chain system also includes a relay system and an endorsement system; wherein the transmitting of the cross-chain message to the second blockchain includes: Instruct the relay node in the relay system to request the endorsement system to perform cross-chain transfer verification, so that the endorsement system performs the cross-chain transfer verification, and after the cross-chain transfer verification passes, send the verification result and signature data to the relay node, and the relay node requests the second blockchain to perform cross-chain transfer based on the cross-chain message, the verification result and the signature data.

6. The method according to claim 5, wherein: The relay node requests the second blockchain to perform a cross-chain transfer based on the cross-chain message, the verification result and the signature data in the following manner: Sending a cross-chain transfer transaction to the second blockchain; the cross-chain transfer transaction includes the cross-chain message, the verification result and the signature data.

7. The method according to claim 5, wherein: The cross-chain system also includes a third blockchain; a third resource contract, a third cross-chain contract and a third system contract are deployed in the third blockchain; wherein the relay node requests the second blockchain to perform a cross-chain transfer based on the cross-chain message, the verification result and the signature data in the following manner: Sending a second transaction to the third blockchain; the second transaction includes the cross-chain message, the verification result and the signature data; enabling the node of the third blockchain to perform audit and evidence based on the second transaction, through the third resource contract, the third cross-chain contract and the third system contract, based on the cross-chain message, the verification result and the signature data; Under the instruction of the node of the third blockchain, a cross-chain transfer transaction is sent to the node of the second blockchain; the cross-chain transfer transaction includes at least the cross-chain message.

8. The method according to claim 1, wherein: The method further comprises: Obtaining the operation result of the cross-chain transfer operation returned by the second blockchain; Receive the operation result through the receiving interface of the first cross-chain contract, and call the first transition contract to process the operation result; If the operation result indicates that the cross-chain transfer operation fails, the first resource in a locked state is unlocked from the contract state of the first transition contract, the first resource is added to the second account in the contract state of the first resource contract, and the first resource in the contract state of the first transition contract is eliminated.

9. A method for cross-chain resource transfer in a cross-chain system, the cross-chain system comprising a first blockchain and a second blockchain; a second resource contract, a second transition contract and a second cross-chain contract are deployed in the second blockchain; the method is executed by a node of the second blockchain; the method comprises: Receive a cross-chain transfer transaction that calls the second cross-chain contract; The cross-chain transfer transaction includes a cross-chain message from the first blockchain; The cross-chain message is used to instruct the transfer of the first resource to the second account through the second resource contract and the second transition contract; Run the second cross-chain contract, trigger the second transition contract to call the second resource contract to update the resources in the second account based on the cross-chain message, so as to perform a cross-chain transfer operation.

10. The method according to claim 9, wherein: The calling the second resource contract to update the resources in the second account based on the cross-chain message includes: Based on the cross-chain message, determining whether the first resource exists in the contract state of the second transition contract; If the first resource does not exist, instruct the second resource contract to mint the first resource, and in the contract state of the second resource contract, add the first resource to the second account; If there is a first resource in a locked state, unlock the first resource in the locked state, and add the unlocked first resource to the second account in the contract state of the second resource contract.

11. The method according to claim 8, wherein: The method further comprises: The operation result of the cross-chain transfer operation is returned to the node of the first blockchain, so that the node of the first blockchain receives the operation result through the receiving interface of the first cross-chain contract, and calls the first transition contract to process the operation result.

12. A cross-chain system, comprising a first blockchain and a second blockchain; the first blockchain is deployed with a first resource contract, a first transition contract and a first cross-chain contract; the second blockchain is deployed with a second resource contract, a second transition contract and a second cross-chain contract; The node of the first blockchain is used to receive a first transaction that calls the first resource contract; the first transaction indicates the transfer of the first resource from the first account of the first blockchain to the second account of the second blockchain; based on the first transaction, the first resource is transferred from the first account to the first transition contract, and the sending interface of the first cross-chain contract is called through the first transition contract to transmit a cross-chain message to the second blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract; The node of the second blockchain is used to perform a cross-chain transfer operation based on the cross-chain message.

13. A device for transferring resources across chains in a cross-chain system, the cross-chain system comprising a first blockchain and a second blockchain; the first blockchain is deployed with a first resource contract, a first transition contract and a first cross-chain contract; the second blockchain is deployed with a second resource contract, a second transition contract and a second cross-chain contract; The device is deployed on a node of the first blockchain; the device includes: A receiving module, configured to receive a first transaction for invoking the first resource contract; the first transaction indicates a transfer of a first resource from a first account of the first blockchain to a second account of the second blockchain; An execution module is used to transfer the first resource from the first account to the first transition contract based on the first transaction, and call the sending interface of the first cross-chain contract through the first transition contract to transmit a cross-chain message to the second blockchain; the cross-chain message is used to indicate the transfer of the first resource to the second account through the second resource contract and the second transition contract.

14. A device for transferring resources across chains in a cross-chain system, the cross-chain system comprising a first blockchain and a second blockchain; a second resource contract, a second transition contract and a second cross-chain contract are deployed in the second blockchain; The device is deployed on a node of the second blockchain for execution; the method includes: A receiving module, configured to receive a cross-chain transfer transaction that calls the second cross-chain contract; the cross-chain transfer transaction includes a cross-chain message from the first blockchain; the cross-chain message is used to indicate that the first resource is transferred to the second account through the second resource contract and the second transition contract; The transfer module is used to run the second cross-chain contract, trigger the second transition contract to call the second resource contract to update the resources in the second account based on the cross-chain message, so as to perform a cross-chain transfer operation.

15. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 11.

16. A computing device, comprising a memory and a processor, wherein the memory stores executable codes, and when the processor executes the executable codes, the method according to any one of claims 1 to 11 is implemented.

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