Research On Three Types Of Signature Schemes With Provable Security In The Standard Model

The rapid development of the Internet has made information security risks a serious problem facing humankind.Digital signature provides security services such as data integrity,authentication,and non-repudiation,which is a key technology for ensuring information security.To meet the security requirements of different application scenarios,researchers have proposed a series of digital signature schemes whose security depends on the ideal random oracle.However,when a random oracle is instantiated with a specific hash function,the corresponding digital signature scheme may not be secure.So designing a security provable signature scheme in the standard model has great practical significance.In addition,some existing signature schemes have some problems,such as the signature can not be transparently converted between the trustee and the agent,illegal users cannot be revoked normally,and the signature schemes have improved security while reducing signature efficiency,and so on.To solve these problems,three digital signature schemes with provable security in the standard model are proposed.(1)In view of the anonymity and controllability of blind proxy signature,borrow the design ideas of partial blind signature.The security definition of partial blind proxy resignature is introduced.Based on the improved Shao's scheme,a bidirectional blind proxy re-signature scheme in the standard model is constructed,which allows public information negotiated by the trustee and the agent to be added to the final re-signature.It not only realizes the transparent conversion of the signature from the trustee to the agent,protects the privacy of the re-signature information,but also prevents the trustee from illegally using the re-signature.The analysis results show that the new scheme meets the requirements of correctness,versatility,partial blindness and unforgeability,and its performance is more suitable for e-government data exchange and cross-domain identity authentication systems.(2)Aiming at the problem that the identity-based proxy re-signature scheme does not support user revocation and so on,the revocable identity-based proxy re-signature scheme is introduced,its security definition is given,and the specific implementation scheme is constructed.To further improve the performance of signature verification,the scheme is extended to a server-assisted verification identity-based proxy re-signature scheme,and the extension scheme is proved to be safe under adaptive selection message attacks and collusion attacks.The results show that both schemes support efficient user revocation.Compared with the similar schemes,the server-assisted authentication identity-based proxy re-signature scheme greatly reduces the computation cost of the verifier.(3)Aiming at the problem of the inefficiency of identity-based signature schemes,a new online/offline identity-based signature scheme is proposed.In the standard model,it is proved that the scheme satisfies strong unforgeability under adaptive identity selection and message attacks.Due to the pre-calculation work in the offline phase,it requires only one subtraction and one multiplication in the online phase,which can generate a legal signature in a very short time.