In the modern systems of information security, as the digital signatures can not only provides the data integrity and authentication, but also meets the demands of E-commerce and E-government, it became one of the key technologies to ensure the information security and played a very important role in the network communications.Designated verifier signature scheme and designated verifier proxy signature scheme are two types of special signatures.The designated verifier signature scheme enables the designated verifier to verify the validity of the signature, while the designated verifier proxy signature scheme allows a person called proxy signer, to sign on behalf of an original signer,and the designated verifier verify the validity of the proxy signature. The property and charateristics of these two types of signature make them widely used in electronic business and E-government. After research, we found that there were such kind of issues as low performance and imperfect security in the current designated-verifier signature. So it is important to design secure and efficient designated verifier signature schemes. In this paper, some explorations have been made and a new ID-based designated verifier signature scheme and a new efficient designated verifier proxy signature scheme are given respectively.What have been studied in this paper and the main results are as follows:Firstly, this paper presented the early prior knowledge and the conception and the definition of the designated verifier signature. Proposed a new ID-based designated verifier signature scheme based on the advantages of the existing schemes, listed the interrelated algorithm of the scheme. Carried on security analyzed and has given the theorem and certification in secure aspect, gave the cost of calculating amount to the scheme. The results showed that the new signature scheme proposed had meet the specific nature of the designated verifier signature.Secondly, combine the characteristic of the proxy signature and the designated verifier signature scheme, proposed a new efficient designated verifier proxy signature scheme which satisfied the special secure nature of the proxy signature and the designated verifier signature.And also given the interrelated algorithm of the scheme. Proved the security of the new scheme proposed. Compared with the existing schemes referd to the calculation while the results imply that the new scheme is more efficient and practical. |