Research On The Proxy Signature System

With the popularity of Internet, E-commerce and E-government, it brings about huge benefit to the the social economic development and also brings more serious situation. Due to the defect of network, such as immoral attack and the weak of laws, the network is always suffer from various attacks, which causes the loss of confidential data. Such problem can easily destroy company’s and government’s working system which makes the financial losses and even do harm to the social stability. Therefore, people become more and more aware of the seriousness of the information security. All of the word consider the information security as one of the most important problems of the people’s livelihood.Currently, the digital signature technology is a significant tool which serves for integrity of information and the identity verification. To adapt to different situations, a series of particular digital signature schemes have been emerged, such as group signature, ring signature, blind signature, agency signature, agency ring signature, etc. Since agency signature and ring signature are two special forms of digital signature, many scholars have been done a deeper research. Such projects become the most popular researches in recent years. Based on the different requirements, many new signatures emerge with the transformed form, such as agency ring signature, agency re-signature, agency blind signature. These new styles of digital signature as the new research filed have a good future on E-commerce, E-voting, etc. Therefore, the researches of these projects have high values on both theory and application. This paper focuses on the research of agency signature. This technology can apply to various situations such as anonymous E-voting, and E-auction, etc. To improve the security and efficiency problem in current agency ring signature technology, this paper proposes two new efficient and secure signature schemes, and analysis the safety and efficiency. The main work of this paper are as follows:1. Considering the problem of key escrow and security channel requirement for private key in identity-based agency ring signature, we propose a certification-based agency ring signature scheme and give a security proof and construct a safety model.2. Based on the security proof, we propose a certification-based agency ring signature scheme, and prove it has unforgeability in the random model. We use ring forking lemma to prove the scheme has unconditional anonymity and meets the requirements of correctness and indistinguishability. Comparing to the current scheme, the computing spending of the bilinear pairing is decrease from O(n) to O(1), the proposed scheme has higher efficiency.3. This paper proposes certificateless-based agency ring signature scheme. Such scheme has the advantage of both agency signature and ring signature. It can protect the agency signature customer’s unconditional anonymity. At the same time, this scheme can overcome the key escrow and have no use for certification. So the problem of key management in the traditional public key scheme has been solved. Our scheme also can meet the requirements of verifiability, unconditional anonymity, unforgeability, nonrepudiation, identifiability for agency ring signature. Comparing with the current scheme, the proposed scheme also has higher efficiency.