A New Electronic Cash Protocol Using a Modified ElGamal and an Untraceable Signature Scheme

In this paper, a new transaction protocol based on electronic cash using a modified ElGamal signature and a secure blind signature scheme is proposed. With the extension of untraceable electronic cash, a fair transaction protocol is designed which can maintain anonymity and double spender detection and attaches expiration date to coins so that the banking system can manage its databases more efficiently. The security of the system is based on discrete logarithm problem and factoring problem.Also our protocol has better performance than similar protocols. So the new protocol is very efficient.