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Research On Threshold And Proxy Digital Signature Schemes

Posted on:2015-09-02Degree:DoctorType:Dissertation
Country:ChinaCandidate:D N LiuFull Text:PDF
GTID:1108330482955767Subject:Computer application technology
Abstract/Summary:PDF Full Text Request
The application of digital signature technology can prevent network transmission information from forgery, denial and tampering. This dissertation mainly discusses threshold signature, threshold proxy signature and multi-proxy multi-signature schemes. The main research work and innovation of this paper are listed as below.(1) Threshold signature technology is investigated. We propose a threshold signature scheme that members can be dynamically added and deleted. Then we propose anther threshold signature scheme that the members consult together to generate proxy secret share. ①We represent a novel threshold signature scheme based on the assumption of discrete logarithm problem difficulty. For the maintenance, the group members can be dynamically added and deleted. Comprehensive analysis of all the stages, the amount of calculation is less in the proposed scheme. ②Based on the difficulty of discrete logarithm problem and secret sharing method, a new threshold signature scheme without key distribution center is proposed. All the members consult together, and everyone generates his own secret share. Each member generates his partial signature and sends it to SC. SC verifies all the partial signatures that he received. If they are correct, SC combines the partial signatures to generate the final threshold signature. The analyses of correctness, security and efficiency show that the proposed scheme is secure and feasible.(2) Threshold proxy signature technology is investigated. A nonrepudiable threshold proxy signature scheme is proposed. In the initialization phase, the public key of signer is verified by the method of zero knowledge proof. The original signer only calculates a public proxy share and broadcasts it to the proxy group. The proxy signer generates his proxy partial signature by his own proxy secret share, which is derived from the original signer’s public proxy share. Then the proxy signers’signatures are combined to generate a final threshold proxy signature. In the verification stage, the final proxy signature is verified according to the public keys of the proxy signers. So each proxy signer cannot deny his own signature. According to the security model that the adversaries are classified into three types, the progresses that the adversaries forge the final proxy signature are simulated, and the proposed scheme is proved to be secure.(3) Multi-proxy multi-signature (MPMS) technology is investigated. We propose a MPMS scheme and a TMPMS scheme that original signers can appoint different proxy groups. ① We give a formal definition and security model of the MPMS schemes, and propose a MPMS scheme with different proxy groups. To prove the safety of the new scheme, we improve a security model to testify that the new one is secure based on the computational Diffie-Hellman assumption. ② We propose a new threshold multi-proxy multi-signature (TMPMS) scheme in which each original member can designate a proxy group in his own organization. Moreover, the threshold value of each proxy group is unique. We develop a security model to prove the high security and strong unforgeability of the proposed scheme. We analyze the security of our scheme based on the four types of adversaries tested in the security model. Compared with previous schemes, the new scheme offers higher security.(4) Digital signature is applied in mobile Ad Hoc networks. The core problem of security in mobile Ad Hoc networks is key management of network nodes. Because of the properties of no centralized control and dynamical topology in mobile Ad Hoc networks, we propose a new key management scheme without key management center and secure channel. Website nodes consult together to generate the initial keys and update the keys, without the help of key contribution center. For the secret transmitting information, nodes encrypt it, and then get the digital signature of the ciphertext, so that the secret information can be transmitted on the public channel.
Keywords/Search Tags:information security, cryptography, threshold signature, threshold proxy signature, multi-proxy multi-signature, mobile Ad Hoc networks
PDF Full Text Request
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