Construction method of strong anti-collision chameleon hash function

Abstract

The invention discloses a construction method of a strong anti-collision chameleon hash function, which comprises the following steps of S1, inputting a security parameter n, and generating public andprivate key pairs (PK, SK) by a system, the public key PK being capable of specifying a message space M, a random space R and a chameleon hash function range Y; and S2, inputting the public key PK generated by the KGen and a message m Epsilon M, Hash algorithm outputting Hash y Epsilon Y and random r Epsilon R; and S3, inputting a public key PK, and outputting b belongs to {0, 1} through a Hash Epsilon Y of the message m Epsilon M and a random vector r Epsilon R check algorithm, if b = 1, then (y, r) is a valid hash of the message m, otherwise is invalid; and S4, inputting a private key SK, amessage m Epsilon M and a corresponding Hash random pair (y, r), and a new message m' Epsilon M to output a random vector r' satisfying HCheck (PK, m', y, r ') = 1. The invention also discloses a verification method of the strong anti-collision chameleon hash function. The method can resist strong anti-collision attacks and can be well applied to the scene of a high-security chameleon hash function.

Description

technical field [0001] The invention relates to the technical field of information security, in particular to a construction method of a strong anti-collision chameleon hash function. Background technique [0002] The chameleon hash function is a special hash function. In addition to being used for ordinary hash functions, it can also adapt the message content of the hash function with a private key. Therefore, it is widely used in chameleon signatures, In the design of online and offline signatures and some advanced encryption schemes. The chameleon hash function with strong anti-collision is a more secure chameleon hash function. This kind of chameleon hash function cannot forge a legal new hash message pair after many hash message pairs are known by the adversary, so In addition to replacing the general chameleon hash function, it can also be applied to scenarios such as purifiable signatures and mutable blockchains. [0003] The existing strong anti-collision chameleon...

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Problems solved by technology

[0003] Existing strong anti-collision chameleon hash functions are based on traditional difficult problems such as large number decomposition and discrete logarithm, so they cannot resist the attack of quantum computers

Existing chameleon hash functions that can resist quantum computers, such as the literature "Cash, D., Hofheinz, D., Kiltz, E., & Peikert, C. (2012). Bonsai trees, or how to delegate a lattice basis. Journal of cryptology ,25(4),601-639."The proposed chameleon hash function cannot resist strong anti-collision attacks

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