TOMIN: Trustworthy Mobile Cash with Expiration-date Attached

摘要

Online mobile payment systems based on mobilecash provide privacy to customers and are feasible for realpoint of sale, virtual point of sale, and person-to-personmobile commerce scenarios. The merchant does not performcomplex operations and the bank verifies the validity of themobile cash before the merchant delivers the product. Thebank must store the mobile cash spent in a database toprevent a double spending attack. In this paper, we proposean efficient mobile cash scheme in which the customerattaches the expiration date and deposit date. This propertyreduces the size of the bank’s database and the customermust spend the mobile cash before expiry. Moreover, thecustomer attaches the merchant’s identity into the mobilecash in the deposit phase. The scheme requires lowcomputational cost and is suitable for mobile devices.