A Multivariable Proxy Re-Signature Method Against Collusion Attacks

Abstract

A multivariable-based proxy re-signature method capable of resisting conspiracy attacks comprises the steps of system generation, key generation, re-signature key generation, trustee A signature generation, agent re-signature generation, and re-signature correctness verification. As two random keys (H<*>A and H<*>B) used by a trustee A and a trustee B in proxy re-signature are generated by adopting a trusted third party, and are used for generating new re-signature keys respectively, an agent converts a signature of the trustee A to a certain message into a signature of the trustee B to the same message by using the corresponding new re-signature key, and the confidentiality of the random keys is high, whether the trustee B and the agent or the trustee A and the agent cannot conspire to acquire the private key of the other trustee, that is, the conspiracy attacks can be resisted effectively. The multivariable-based proxy re-signature method is high in efficiency, safe, reliable, and capable of resisting the conspiracy attacks of the trustee A and the agent or the agent and the trustee B, and can be used in proxy re-signature.

Description

technical field [0001] The invention belongs to the technical field of information security, relates to a multi-variable public key system and proxy authentication of messages, and in particular to a multi-variable proxy re-signature method which can resist collusion attacks. Background technique [0002] Proxy re-signature means that a semi-trusted agent (who has a re-signature key related to the information of trustee A and trustee B) is responsible for converting trustee A's signature on a message into trustee B's signature The signature of the same message, meanwhile, requires the agent to only have the re-signature key, and cannot learn the private keys of trustee A and trustee B, and cannot generate new signatures on behalf of trustee B or trustee A. [0003] The security of proxy re-signature is divided into internal security and external security. External Security: Illegal third parties cannot collude with signing parties. Internal security: the principal B and th...

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Problems solved by technology

[0007] Sun Changyi, Li Yifa, Si Xueming. Proxy re-signature scheme based on multivariable public key cryptosystem [J]. Computer Engineering, 2012, 38(17): 116-118. For the first time, a rainbow scheme based on multivariable system was proposed A proxy re-signature scheme, but unfortunately, as stated in Section 3.3 of the text, this scheme cannot resist collusion attacks "...the agent and the trustee conspire...the private key information of the principal will be leaked..."

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