Study On Proxy Signature And Its Applications In E-commerce

This thesis mainly discusses proxy signature and its applications in e-commerce. Firstly, we introduce digital signature, proxy signature, and e-commerce security simply. Next, we introduce some common digital signature schemes which are the base of proxy signature. And the security properties of them are discussed. Then, we introduce proxy signature systematically, including the notion and class of proxy signature as well as its security properties. Some typical proxy signature schemes are studied deeply. And their security properties are analyzed. Lastly, we study the applications of proxy signature in e-commerce. Then main results of this thesis are as follows:1). Based on the security properties, such as strong unforgeability, strong identifiability and prevention of misuse, which are needed by proxy signature, we present some terrible attacks on K.Zhang's proxy signature, designated-receiver proxy signature scheme and Shum and Wei's proxy signature scheme with proxy signer privacy protection, improved schemes on these schemes are proposed. The improved schemes can resist the serious attacks which we have discovered. The new schemes keep the merits of the original schemes, with the improved security and practicability.2). A secure e-payment protocol based on proxy signature is proposed. From this protocol, customers can make proxy search and buy special products or services on behalf of them.