Computational resources for mobile E-wallet system with observers

The next generation of individual payment systems that will replace traditional smart cards will be mobile devices supplied with e-wallet functions. The spread of such e- wallet systems will depend on their security, functionality, ease of use and the effectiveness of realization. This paper proposes an effective realization of e-wallet system, providing e-cash divisibility, off-line payment and deposit options as well as purchaser's anonymity against the vendor and satisfying general electronic payment security requirements of double spending prevention, unforgeability as well as unclonability of purchaser's identity. The latter is achieved through the implementation of bank's tamper resistant hardware agent, known as observer, provided with physically unclonable function (PUF), capable of yielding a unique unclonable code (UUC), in user's mobile device. The estimation of the necessary computational resources in the usage of the proposed mobile e- wallet system is presented in order to determine whether the proposal is worth the computation cost.