Security Analysis Of Group (Blind) Signatures And Research On Its Applications To Electronic Cash

As holding advantages of both group signatures and blind signatures, group blind signature has played an important role in electronic commerce, electronic vote etc. Design and cryptanalysis on group (blind) signature is always the hotspot in the field of cryptography. The paper analyzed the security of Lee-Chang group signature and its derivatives, pointed out that they can all be universal forged and part of them are untraceable, and then proposed a secure group signature by improving the Xie-Yu Group signature witch was not coalition-resistant. Finally, using the idea of blind signature of knowledge proposed by A.Lysyanskaya and Z.Ramzan, presented a secure and efficient group blind signature scheme based the above-mentioned group signature, and analyzed its security. The scheme has met all security requirements of group blind signature.Electronic cash is the kernel and pivotal tache of electronic commerce. The paper researched on the basic model, relative characteristic and key technology, and reviewed the research course of E-cash systems, and then proposed a secure and practical off-line E-cash systems based on the above-mentioned group blind signature, finally analyzed its security.