Efficient off-Line Electronic Cash System Based on the Representation Problem

摘要

An offline electronic cash system based entirely on discrete logarithms ispresented. Using the representation problem as a basic concept, some techniques are introduced that enable the construction of protocols for withdrawal and payment that do not use the cut and choose methodology of earlier systems. As a consequence, the cash system is much more efficient in both computation and communication complexity. The correctness of the system can be proven to a very great extent. The construction of an efficient cash system with security related to factoring or computation of RSA roots, in an analogous way to the discrete log based system, is discussed. The decision variant of the Diffie-Hellmann problem, that is strongly related to undeniable signatures, is discussed.