OFF-LINE ELECTRONIC CASH SYSTEMS BASED ON A SECURE COALITION-RESISTANT GROUP BLIND SIGNATURE SCHEME

Abstract. Secure and efficient electronic payment systems are sig-nificant for electronic commerce. Fangguo [9] proposed a fair elec-tronic cash system with multiple banks based on a group signature scheme of Camenisch [5] and the group blind signature scheme of Lysyanskaya [11]. Ateniese proved in [1] that these group signature schemes does not satisfy the property of coalition-resistance. In this paper we extend the electronic cash system of Fangguo by using a se-cure coalition-resistant group blind signature scheme. The main ben-efits of our off-line electronic cash system, compared to the scheme of Fangguo, relate to the underlying group signature scheme’s improved efficiency and provable security. 1.