Research Of Proxy Signature Technology

Digital signature plays a important role in electronic commerce. Proxy signature, as a branch of digital signature, has been a hot research point as soon as it's appearance because it's significant function in many aspects, such as electronic commerce, mobile agent, etc. So the research for proxy signature technology has academic and apply value in a certain extent.This thesis first deals with the importance of information security and the significance of digital signature in information security. Secondly, we introduce the basic concepts and basic theories of cryptology, digital signature and proxy signature. Then presents several representative kinds schemes raised recently. In order to expand the application fields of proxy signature, the kind of number-limited proxy signature was raised in this paper based on the research of former schemes. The main method is combining the thought of forward signature with some proxy signature already been raised. Our research achievements are follows:1. Based on the Fiat-Shamire proxy signature schemes, modifying the scheme's parameters and protocol procedures in virtue of some references from the forward-security digital signature schemes raised by Bellare, we raise a number-limited proxy signature schemes with forward security property. The proxy secret key is forward security in this scheme.2. Second, we combine the main idea in first scheme with the discrete logarithm proxy signature schemes for the sake of efficiency. Then we raise a new number-limited proxy signature schemes based on discrete logarithm problem. It is obvious that the compute equations in this scheme are simpler then the former. So this scheme has high efficiency.