Improvement of efficiency in (unconditional) anonymous transferable e-cash

Abstract. The practical advantage expected from transferable e-cash compare to non-transferable is the significant reduction of the interaction number between the bank and the users. However, this property is not fulfilled by anonymous transferable e-cash schemes of the state-of-the art. In this paper, we first present a transferable e-cash scheme with a reduced number of communications between the bank and the users that fulfils the computational anonymity property. Next, we present a transferable e-cash scheme with a reduced interaction number that fulfils the unconditional anonymity. This latter scheme is quite less efficient