Mobile, Divisible, and Safe E-Cash System

Mobile, divisible, and safe e-cash system adapts on mobile terminals for e-payment which can circulate in multiple banks. The usage of the divisible e-cash does not need pass bank, which the bank has not the bottleneck of e-business. The author’s thesis discusses on the withdrawal protocol, payment protocol, transferable protocol, deposit protocol, and update of e-cash, based on elliptic curve cryptography (ECC).The system is simple, efficient, secure, and fit for the mobile e-payment terminals in which storage, power, operand capacity, and network bandwidth supply are extraordinarily restricted. The system can protect from double spending, non-frameability, eavesdropping, tampering, and “perfect crime” effectively too. It can save from mis-identity attacks, two-layer anonymity attacks, and linking attacks.

An improved E-payment protocol based on quantum blind signature without entanglement

E-payment plays an important role in modern daily life, so the security problem of E-payment has been widely concerned by researchers. In a recent paper [Int. J. Theor. Phys. 57, 2657 (2018)], the authors presented a trusted third-party E-payment protocol based on quantum blind signature without entanglement. In this paper, we show that there is a serious security flaw in their E-payment protocol. That is, the partial keys will be disclosed by performing a simple attack strategy. Furthermore, we propose an improved E-payment protocol and analyze its security.