An Off-line Electronic Cash Scheme Based on Proxy Blind Signature

Abstract

In a proxy signature scheme, the proxy signer generates a signature on a message. By the combination of a blind signature with a proxy signature, a proxy blind signature permits the proxy signer produce a blind signature on a message. In this paper, a proxy blind signature scheme based on bilinear pairings is proposed. The proxy blind signature scheme is proved secure upon the discrete logarithm assumptions, decisional bilinear Diffie–Hellman assumptions and Chosen-Target computational Diffie–Hellman assumptions in the Random Oracle Model. In the real world, the customers can withdraw and store money from all levels of the bank. On the basis of the new proxy blind signature, this manuscript proposed an electronic cash (e-cash) scheme. The e-cash scheme can provide unforgeability of e-cash, anonymity of honest customers and efficient traceability of double spending.