An Attribute-Based Encryption Method Against Leakage of Key Continuous Auxiliary Input

Abstract

The invention provides an attribute-based encryption method for resisting continuous auxiliary input leakage of secret keys. The method comprises that a private key generation center inputs a system security parameter lambda and a legal attribute set U, constructs an m-dimensional vector and embeds the m-dimensional vector in a system public key PK and a system master secret key MSK; the private key generation center authenticates an attribute set omega own by a user and generates a user private key Skomega containing the m-dimensional vector by utilizing the system master secret key MSK and the system public key PK; an encryption party encrypts to-be-encrypted information by utilizing the system public key PK and a set access strategy, thus generating ciphertexts containing mn <1 >-dimensional vector; and a user can decrypt to obtain plaintexts only when the attribute of the user private key Skomega satisfies the access strategy of the ciphertexts. According to the method, the system master secret key MSK and the user private key Skomega can be continuously and limitlessly leaked; the compatibility of the user private key Skomega is improved; and on the premise of ensuring the security of the encryption information, the length of the system master key and the length of the user private key are reduced.

Description

technical field [0001] The invention relates to the technical field of cryptography, in particular to an attribute-based encryption method against key continuous auxiliary input leakage. Background technique [0002] As an important branch of modern cryptography, public key cryptography has developed rapidly in recent years. In the public key encryption mechanism, each legal user has a pair of different encryption key and decryption key, and it is computationally infeasible to deduce the decryption key from the known encryption key. The encryption key can be made public, and the decryption key must be kept secret by the user himself, that is, the user cannot disclose any bit of information to others, otherwise, the security of the system will be destroyed. Therefore, the security of the public key encryption mechanism is based on the fact that the decryption key must be kept secret. [0003] Modern cryptography assumes that all attackers cannot obtain any information about...

AI Technical Summary

Problems solved by technology

However, so far, there are few studies on solving the key disclosure problem under side-channel attacks in ABE.

[0006] Aiming at the problem of key leakage under side channel attack in ABE, Lewko et al. [12] At the TCC annual meeting, the dual-system encryption and the bounded leakage model were combined to propose an adaptive security ABE scheme against continuous memory leakage, which supports the leakage of the master key and user attribute private key, but only the key is allowed Bounded leakage of , requires that the old version of the key must be completely cleared from memory, and this scheme cannot be used in combination with other cryptographic schemes

However, in practical applications, due to the wide variety of ABE key construction methods, it is easier to use ABE in combination with other cryptosystems. In particular, the old version of the key often retains some information in the memory after the update

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