Multi-backup secure deletion method and system based on blockchain

Abstract

The invention discloses a multi-backup secure deletion method and system based on a blockchain, and the method comprises the following steps: setting a backup number and a corresponding backup addressthrough a cloud server after the initialization of the system and the generation of a secret key, transmitting the backup number and the corresponding backup address to a data owner, and generating apre-deletion sequence; encrypting a file by using different keys to generate a plurality of ciphertext backups, and generating an index according to keywords in the file; generating, by the data owner, preparatory integrity and delete evidences; in a ciphertext query stage, calculating, by a user, a trap door and uploading the trap door to a smart contract, and calculating, by the smart contract,a corresponding decryption key and querying a file number; sending, by the cloud server, a ciphertext backup to the user according to the file number, and decrypting, by the user, the ciphertext by using a decryption key; in a deleting stage, sending a deleting request to a cloud server, and deleting, by the cloud server, all backups of the corresponding file according to the request, generatingdeleting evidences, sending the evidences to the data owner and storing the evidences into the blockchain; and verifying, by the data owner, whether the cloud server deletes the evidences according tothe received evidences, and tracking the corresponding responsibility of the cloud server and the user according to the evidences of the evidence chain. According to the method, the requirements of cloud data sharing and safe deletion can be well met, and searchable encryption is provided for valid users.

Description

technical field [0001] The invention belongs to the technical field of information security, and relates to a searchable and encrypted multi-backup safe deletion method of a block chain, which can provide searchable encryption of cloud server ciphertext data, multi-backup verifiable safe deletion and traceable responsibility. Background technique [0002] As a new service model, cloud computing makes data storage and data sharing more convenient and economical. Users can access a shared pool of configurable computing and storage resources anytime, anywhere. Due to its low management overhead and instant access, more and more people are willing to store data in the cloud and enjoy the convenience brought by cloud services. However, there are still many new problems and challenges in the cloud environment, especially in terms of security and availability. [0003] First of all, due to natural disasters and uncertain failures of cloud storage devices, data owners back up data...

AI Technical Summary

Problems solved by technology

However, these solutions are based on the current encryption technology to ensure that the data outsourced to the cloud server cannot be recovered, but the ciphertext is still in the cloud. With the rapid development of various technologies, there is no guarantee that the data in the cloud will not be cracked in the future.

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