The Research On The Digital Signatures Based On The Zero-knowledge Proof

The cryptology is the branch of the information security and deploys the methods such as the message encipher/decrypt, the figure signature, the identity authority and key the exchange and so on to safeguard secure quality of message in the network communication. The authentication system is the first line of defence in the information security system. As the key technologies of the information security, the hash function, the zero knowledge proof and the digital signature are just the important embranchment studies of the research and application based on the cryptology. On the purpose of the researching and designing an authentication system with high secure level and reliable performance, it should start with the key technologies of the cryptography to design the scheme with the secure properties of availability, reliability and effectiveness, which causes the final security on the internet.In this paper, the hash function, the zero-knowledge proofs and the digital signatures are researched in detail, the main results are listed as following:1.It disclosed the weakness of hash function in MD structure, and restricts the security of the hash function used in this paper.2.The zero-knowledge proof schemes processing RSA digital signature (or DSA digital signature) are proposed which presents a new method to prevent RSA digital signature (or DSA digital signature) from propagating arbitrarily. In the schemes, the signer has not to give the signature of a message directly, but to provide a zero-knowledge proof to the digital signature of the message. These schemes, which are the combination of a zero-knowledge and digital signature, can be widely used to protect the copyright of information product.3. Based on the RSA, DSA and zero-knowledge, a confirmer signature is proposed. As an improved scheme of the undeniable signature, this scheme not only prevents the signatures from propagating arbitrarily, but also eliminates the disadvantage of the undeniable signature, which means, that when the signer doesn't want to cooperate to confirm his valid signature subjectively, or cannot cooperate objectively, then his signature cannot be verified. With the security properties of the zero-knowledge, the non-transferability and the invisibility, the confirmer is able to transfer a confirmer signature into a general signature that can be verified by anyone if he or she can obtain it.