Abstract: The present application provides a transaction-based electronic contract forensics method and system: when a user wants to perform forensics for an electronic contract in a blockchain digital deposit platform, initiating, by a present electronic contract platform, a forensics request for the electronic contract; obtaining, by the blockchain digital deposit platform, the forensics request and querying deposit information; obtaining a transaction hash value of the deposit information after the deposit information is queried; querying a deposit transaction corresponding to the deposit platform; obtaining a digest; decrypting the digest, to obtain a storage index table; verifying validity of a private-key signature of the deposit transaction; downloading transaction data of the deposit transaction according to a data index; decrypting the transaction data; and verifying validity, legitimacy, and integrity of the decrypted transaction data.

Abstract: The present application discloses a smart contract-based electronic contract deposit system, including an electronic contract platform, a blockchain deposit platform, and a transaction processing smart contract created by the electronic contract platform or the blockchain deposit platform, where the blockchain deposit platform includes a plurality of deposit nodes that provide deposit services for the electronic contract platform. In this way, the following problem may be resolved: regarding an existing manner of storing an electronic contract in a centralized way, during a subsequent process of invoking electronic contract data, the stored electronic contract data becomes untrustworthy because the contract data is at a risk of being easily tampered with and forged.

Abstract: This application provides a decentralized electronic contract attestation platform, where the attestation platform is connected to a user client through a deposit thread and a forensic thread that are established with an existing electronic contract platform; the attestation platform includes a deposit unit and a forensic unit; the deposit unit is configured to verify transaction data of a deposit transaction initiated by the user client, and if the verification is passed, upload and store the transaction data on a chain; and the forensic unit is configured to obtain, based on a forensic request sent by the user client, transaction data that corresponds to the forensic request and is stored in a blockchain, and send the transaction data to the user client. According to this application, deposit and forensic operations of an electronic contract are correspondingly completed by using the established deposit thread and forensic thread.