Encryption system and method for resisting re-encryption key leakage and capable of cancelling attributes

Abstract

The present invention provides an encryption system and method for resisting re-encryption key leakage and capable of cancelling attributes. The method comprises: 1, setting the parameters of an encryption system; 2, generating the main private key and the public key of the encryption system; 3, generating a user private key; 4, building a re-encryption key tree; 5, generating a cryptograph file; 6, cancelling attributes; 7, performing re-encryption agency; 8, accessing the cryptograph file; 9, determining whether the update position of the cryptograph file is 1 or not; 10, decrypting an un-updating cryptograph file; 11, updating the private key; 12, decrypting the update cryptograph file; and 13, quitting the encryption system. Through adoption of a dual-agency re-encryption server model, the encryption system and method for resisting re-encryption key leakage and capable of cancelling attributes can resist the leakage of the re-encryption key. When the attributes are cancelled, an attribute user group is employed to construct the re-encryption key tree so as to effectively, timely and accurately cancel the indirect attributes. When the encryption is performed, the secret is dispersed to resist the conspiracy attack.

Description

technical field [0001] The present invention belongs to the technical field of data encryption, and further relates to an attribute-reversible encryption system and method in the technical field of data security that resist re-encryption key leakage. The invention can be used to realize fine-grained access control and data protection in the cloud storage environment. Background technique [0002] The attribute-based encryption method is a new public key encryption method that supports the many-to-many mode, that is, the decryption object is no longer just a specific user, but a group that meets the decryption conditions. This feature enables attribute-based encryption methods to be used to implement fine-grained access control. Attribute-based encryption methods mainly include two types, which are ciphertext-policy attribute-based encryption methods and key-policy attribute-based encryption methods. In the ciphertext policy attribute-based encryption method, the access str...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to overcome above-mentioned prior art when carrying out proxy re-encryption, has adopted untrustworthy proxy re-encryption server to manage re-encryption key, can't solve the key leakage problem of proxy re-encryption server; , timely attribute revocation; embedding the attribute revocation list into the ciphertext may cause security problems; although it can resist the collusion attack between multiple illegal users, it cannot resist the collusion attack between the illegal user and the proxy re-encryption server , providing an attribute reversible encryption system and method against re-encryption key leakage

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