Client secure deduplication method of ciphertext data in cloud storage

Abstract

The invention discloses a client secure deduplication method of ciphertext data in cloud storage. The method comprises the following steps of: (1) key generation; (2) file initialization; (3) data block initialization; (4) data block verification; (5) file storage; (6) challenge generation; (7) proof generation; (8) proof verification; and (9) file decryption. According to the method of the invention, a secure key generation protocol is constructed based on blind signature, and therefore, secondary encryption of convergence keys is realized, and the security of the keys can be ensured; and a signature-based ownership proving method is put forward based on the above encryption, and with the method adopted, it can be ensured that a user can prove his or her ownership of a certain file in the could storage to a could server in a safer and more efficient way, and file-level and block-level deduplication of a ciphertext file can be realized.

Description

technical field [0001] The invention relates to the technical field of cloud storage and information security, in particular to a client-side security deduplication method for ciphertext data in cloud storage. Background technique [0002] With the widespread use of cloud storage services, more and more enterprises and individuals outsource their data information to cloud service providers (Cloud Service Provider, CSP), which will generate a large amount of redundant data in the cloud. Therefore, a severe challenge that cloud service providers will face is how to efficiently manage the continuously increasing data. [0003] To this end, the researchers proposed a client-side data de-duplication technology, which enables the CSP to store the same file only once, and all users who own the file can only access the file through that unique copy. More specifically, CSP only executes the storage of data files when it receives the first user upload request; for subsequent upload r...

AI Technical Summary

Problems solved by technology

However, there is a big security problem in client data deduplication: an attacker may be able to obtain the download permission of the corresponding file from the cloud with a single file hash value

However, there are big security holes in convergent encryption, such as dictionary attack: for predictable files, attackers can easily derive the convergent key and detect whether the file exists in the cloud server

In addition, convergent encryption will generate a lot of convergent keys, which makes it very difficult for users to manage their own keys

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