Studies On The Applications Of Group Blind Signature In The E-cash System

Group blind signature schemes combine properties of group signatures and blind signatures, which is widely used in electronic commerce , electronic government,voting and bidding. This paper presents an efficient group blind signature scheme whose basic is G.Ateniese and J.Camenisch's provably secure coalition-resistant group signature scheme based on discrete logarithm problem and A.Lysyanskaya's blind signatures of knowledge,then, analyzes its security.The scheme overcomes the disadvantage of the C.Popescu's,and has the property of unlinkability.D.Boneh and X.Boyen proposed a group signature scheme based on bilinear pairings which can be found in Elliptic curve.but it doesn't have the exculpability property.This paper improved that scheme,and proposed a more efficient short group signature scheme whose length of signature is even shorter and satisfies the exculpability property.Furthermore,we blind that short group signature scheme,and made it suitable for practical e-cash system.E-cash payment is the kernel and pivotal tache in electronic commerce.This paper studies on the component of e-cash system and its security.Finally,combing the idea of marking and our two proposed group blind signature schemes,we successfully proposed two fair e-cash schemes which can prevent the blackmailing and double-spending.