Cash-like payments in electronic commerce and at the traditional point of sale are expected to be beneficial, e.g., because of privacy protection, low transaction costs, and irrevocability. Therefore, we discuss how to design electronic cash in a way that it both mirrors the most important characteristics of raditional cash, but also fulfils the expectations which arise towards electronic means of payment. We analyse the problems and trade-offs between the different characteristics to be implemented. This analysis is based on a user survey and a review of existing technologies for electronic payment systems. Finally we argue why existing systems do not fulfil the critical requirements, and point out future work towards electronic cash which will meet more requirements
