A scheme for analyzing electronic payment systems

The paper presents a scheme for the design, analysis and comparison of electronic payment systems. Three systems are described in detail through this scheme. PayWord is a micro payment system designed by R. Rivest and A. Shamir (1995). It is efficient for repeated payments to the same vendor, and is designed to reduce the use of public key algorithms through the use of hash functions and fast symmetric ciphers. Digicash´s E-cash is one of the most popular electronic payment systems in use today. It is an Internet based system with full user anonymity by the use of blind signatures (D. Chaum, 1982). The central authority must apply a signature on a blinded user generated token. The Internet Keyed Protocol was designed by IBM´s research labs. It is an adequate system for transactions using credit cards or account numbers on open networks, such as the Internet. iKP (P. Janson and M. Waidner, 1996) is in reality, a system that may be used to securely transmit account numbers on the Internet