Analysis And Research Of Proxy Signature Protocols

With the rapid development of computer communication network, people hope to implement rapid and long-distance communication by means of electronic apparatus. As a result, digital signature, which is widely used in society nowadays, comes into being and has been playing a very important role in thefields of information security, identity authentication, data integrity; nonrepudiation and anonymity, etc. As a special digital signature scheme, proxy digital signature is a hot research subject in the field of digital signature schemes recent years. Through transfer the proxy keys, proxy signature allows original signer delegate his/her partial right to the credible proxy signers who can sign the message in behalf of the original signer. Therefore, proxy digital signature can be widely used in many fields, such as e-election, mobile communication, mobile agent, e-commerce activities and so on. Since the year of 1996 when Mambo, Usuda and Okamoto firstly advanced the concept of proxy signature, many proxy signature schemes have been raised, such as proxy mufti-signature scheme, threshold proxy signature scheme and proxy blind digital signature scheme, and also plenty of achievements have been made in the studies of proxy digital signature. However, most of the existing proxy signature schemes have some defects in security, efficiency and feasibility. At the same time, mostly these schemes are based on the discrete logarithm cryptosystems, while the RSA cryptosystem is now the de facto industrial standard and based on factorization; therefore, it is highly desirable to design secure, efficient and feasible proxy signature schemes based on the RSA cryptosystem. This paper made some meaningful attempts in the fields mentioned above.The main contributions of this paper:(1) The paper analyzes a RSA-based proxy signature scheme, and shows its low ability in resistance to forgery attack, and also proposes a new improved signature scheme.(2) The paper proposes two RSA-based proxy multi-signature schemes for each type of the first and second proxy multi-signature. Through analysis and comparison of the presented schemes and proxy multi-signature based on discrete logarithms, the simulation results demonstrate that the former is better than the latter both in security and efficiency performance.(3) The paper analyzes a RSA-based (t, n) threshold proxy signature scheme, and proposes a new improved scheme. Simulation results show that, as the computational and communicational overheads is not greatly raised, the improved scheme is better than the original scheme in security and feasibility.