A post-event supervision method for blockchain based on variable transactions

Abstract

The present invention relates to the field of information security technology, and in particular to the field of future supervision based on blockchain. A post-supervision method for blockchain based on variable transactions is disclosed. It includes two supervision methods. The first supervision method is mainly aimed at transactions involving intermediate nodes. In blockchain transactions, the two parties to a transaction are often not direct buyers and sellers. There may be agents, obfuscators, service providers, oracles and other intermediate nodes. If the intermediate node maliciously delays the transaction, it will cause huge losses to the entire transaction. The supervisor should be able to accept short-term reports on the node after the transaction and quickly determine the responsibility. The second supervision method is mainly aimed at illegal transactions that have already occurred on the chain. In this case, how to specifically modify the transaction. The premise of realizing a blockchain with variable transactions is to require certain presets to be made before the transaction. Using the method of the present invention, innocent transactions do not need to be repeated, which is highly efficient.

Description

Technical Field

[0001] The present invention relates to the field of information security technology, and in particular to the field of future supervision based on blockchain. Background Art

[0002] Blockchain is an emerging technology that underpins blockchain-based transactions and digital currencies. In addition, a number of innovative applications have emerged using blockchain technology, including distributed timestamp services, distributed file storage, identity management solutions, and smart contracts. Blockchain is a distributed database that maintains an ever-growing, immutable list of data. This ensures consensus among all parties and confidence in the integrity of the data stored on the blockchain. The immutable blockchain can be used as a data store for official documents, such as diplomas and certificates. Businesses and governments can record customer and citizen information. Individuals can keep records, such as diaries and work histories. However, when blockchain is used as a public platform, its tamper-proof nature can pose obstacles. For example, blockchains do not operate in isolation, and real-world needs may require the revocation of existing contracts and transactions. Furthermore, on-chain data may contain illegal content, such as illegal images and messages. Therefore, regulation of on-chain data is essential.

[0003] This research focuses on blockchain modification technology. Existing blockchain regulatory solutions include Chameleon hashing with a trapdoor, but this approach suffers from two drawbacks. First, anyone with the trapdoor has the power to modify the blockchain at will, which again poses a centralization challenge. Second, Chameleon hashing is limited to block-level modifications. It's quite possible that only a portion of a block may be illegal, requiring the re-run of many innocent transactions, impacting efficiency. Another approach, based on dual-hash chain technology, aims to achieve consensus blockchain modification, but this fundamentally alters the existing blockchain structure, making it challenging to implement. Summary of the Invention

[0004] The purpose of the present invention is to avoid the problems in the background technology and propose a post-supervision method for blockchain based on variable transactions. The post-supervision can be divided into 1) supervision by the supervisory party when accepting reports to lock transactions and 2) supervision by the supervisory party when discovering illegal transactions and hiding specific transactions.

[0005] The first type of regulation primarily targets transactions involving intermediary nodes. In blockchain transactions, the two parties are often not direct buyers and sellers; intermediaries such as agents, obfuscators, service providers, and oracles may be involved. If an intermediary node maliciously delays the transaction, it can cause significant losses to the entire transaction. Regulators should be able to accept short-term reports on intermediary nodes after the transaction to quickly determine responsibility. The preventive regulatory process before harm occurs specifically includes the following steps:

[0006] When a user needs to request an intermediate node service, he sends a service request M and a time limit T to the intermediate node;

[0007] (1) If the intermediate node accepts the service, it responds with a commitment to the user. The commitment is a signature V = {nonce, T, M, sign {M || T || nonce}} for the service request M and the time limit T, where nonce is a random number to prevent repeated transmission.

[0008] (2) After receiving the commitment, the user initiates transaction 1 to the intermediate node address. The intermediate node accepts transaction 1 and executes transaction 2.

[0009] (3) If the intermediate node maliciously extends the time of transaction 2, the user will report it to the regulator afterwards; after accepting the report, the regulator will query the two transactions on the chain and check whether the time difference between the two transactions exceeds the limit time T in the previous commitment. If transaction 2 has not yet occurred, the regulator will check the time difference between the time of accepting the report and the time of transaction 1, and make an arbitration decision;

[0010] The second type of regulation focuses on illegal transactions that have already occurred on the blockchain, and how to modify these transactions. The prerequisite for implementing a blockchain with variable transactions is to make certain assumptions before a transaction occurs. The remedial regulatory process for issues that have already occurred includes the following steps:

[0011] (5) The initiator of the transaction initiates a transaction and defines it as a mutable transaction. The transaction format includes a triple (S, i, Δt), where S represents a transaction set, i represents the active transaction, and Δt represents the effective time during which the transaction can be changed. The transaction set contains at least one valid transaction and one empty transaction, and all transactions are encrypted.

[0012] (6) It is discovered through real-world inquiries or preventive regulatory measures when no harm has occurred that the initiator of the transaction has initiated an illegal transaction;

[0013] (7) Within the specified time Δt, the regulator marks the active transaction in the illegal transaction as an empty transaction, making the previous transaction invalid; if the active transaction changes, no one can access the original active transaction.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] By adopting the method of the present invention, innocent transactions do not need to be repeated, and the efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram of the post-supervision model of the blockchain of the present invention;

[0017] Figure 2 This is a merkle hash tree structure diagram of the transaction that can be modified in the present invention. DETAILED DESCRIPTION

[0018] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0019] The entities involved in this solution include users: the two parties executing transactions on the blockchain, who may request intermediary nodes to complete their transactions. They may engage in illegal transactions and transfer illegal data for profit, exploiting the blockchain's immutability to ensure data retention. Intermediary nodes: service nodes, providing services to various users, such as asset transfers, identity obfuscation, and data retrieval. While they will serve users according to regulations, they may maliciously delay services, resulting in poor service quality. Regulators: trusted third-party organizations, such as government agencies, are responsible for handling expired, erroneous, and illegal transactions.

[0020] To better illustrate our approach, we take a transaction that satisfies two regulatory scenarios, so that the entire approach can be implemented in one embodiment.

[0021] like Figure 1 As shown, a malicious user A needs to execute two transactions. The first involves finding an intermediary node P to transfer assets. The second transaction involves A sending illegal data to user B. The intermediary node is a maliciously stalling service node. Regulators are online, ready to investigate the illegal transaction.

[0022] (1) User A finds an intermediate node P and sends an asset transfer request to P, which includes the request content M (including the amount of assets to be transferred and the transfer object) and the time limit T for the transaction.

[0023] (2) After receiving the request, P agrees to it and sends a commitment V = {nonce, T, M, sign {M||T||nonce}} to A; where nonce is a random number to prevent repeated transmission;

[0024] (3) After receiving P's commitment, A constructs a mutable transaction (S, i, Δt), where S consists of three transactions: Transaction 1: Transferring digital currency from A's address to P's address; Transaction 2: Transferring illegal data from A's address to B's address; Transaction 3: An empty transaction. Active transactions are Transaction 1 and Transaction 2. The transaction can be changed within Δt.

[0025] (4) Transaction 1 and Transaction 2 are approved by the verification node in the blockchain, and user B and the intermediate node receive the transactions.

[0026] (5) However, due to delays at intermediate nodes, the asset transfer exceeds the previously agreed time. User A reports this to the regulator and sends a commitment A signed by P.

[0027] (6) The supervisor first verifies the authenticity of commitment A. After confirming its authenticity, the supervisor locks the completion time of transaction 1 and then locks the transaction in which node P transfers assets for A. The supervisor checks the time difference between the two transactions and finds that it exceeds time T. The supervisor determines that the intermediate node P is lazy, reduces its credit, and deducts part of its deposit.

[0028] (7) The regulator detects that the data in transaction 2 is illegal data and modifies the transaction, converting the original active transactions (transaction 1 and transaction 2) into transaction 1 and transaction 3 within Δt.

[0029] (8) The detector immediately prohibits any user from accessing the data in transaction 2, and only allows access to transaction 1 (delayed but legal) and transaction 3 (empty transaction). The supervision method for A ends.

[0030] This regulatory scheme does not change the overall structure of the blockchain, because it does not delete the transaction from the blockchain, but only changes the validator's access control to it, that is, everyone's view of the transaction. The Merkle hash tree representation of this mutable transaction is similar to that in the blockchain, such as Figure 2 shown.

Claims

1. A post-event supervision method for blockchain based on variable transactions, characterized in that: The preventive supervision process when no harm has occurred includes the following steps: (1) When a user needs to request a service from an intermediate node, he sends a service request M and a time limit T to the intermediate node; (2) If the intermediate node accepts the service, it responds with a commitment to the user. The commitment content is a signature V = {nonce, T, M, sign {M || T || nonce}} for the service request M and the time limit T, where nonce is a random number to prevent repeated transmission; (3) After receiving the commitment, the user initiates transaction 1 to the intermediate node address. The intermediate node accepts transaction 1 and executes transaction 2. (4) If the intermediate node maliciously extends the time of transaction 2, the user will report it to the regulator afterwards; after accepting the report, the regulator will query the two transactions on the chain and check whether the time difference between the two transactions exceeds the limit time T in the previous commitment. If transaction 2 has not yet occurred, the regulator will check the time difference between the time of accepting the report and the time of transaction 1, and make an arbitration decision; The remedial supervision process for problems that have already occurred includes the following steps: (5) The initiator of the transaction initiates a transaction and defines it as a mutable transaction. The transaction format includes a triple (S, i, Δt), where S represents a transaction set, i represents the active transaction, and Δt represents the effective time during which the transaction can be changed. The transaction set contains at least one valid transaction and one empty transaction, and all transactions are encrypted. (6) It is discovered through real-world inquiries or through preventive regulatory measures when no harm has occurred that the initiator of the transaction has initiated an illegal transaction; (7) The supervisor marks the active transactions in the illegal transaction as empty transactions within the specified time Δt, making the previous transactions invalid; If the active transaction changes, no one can access the original active transaction.

2. A post-supervision method for blockchain based on variable transactions according to claim 1, characterized in that: In step (5), the transaction set S contains multiple transactions, and the transaction types include traditional transactions, deployment transactions, and empty transactions. Traditional transactions are signed by the sender and sent to the receiver, and the transaction content is the cryptocurrency and related data fields. The deploy transaction is used to deploy a smart contract on the blockchain and contains the code to be deployed in the data field; An empty transaction has no sender or receiver, and the data field is empty.

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