Abstract: Variety Cash is a new electronic money system which strikes a balance between functionality, security, and user privacy. The system can encompass both network and stored-value card based payment mechanisms, with transferability between them, hence the name.
Ref: Appears in Proceedings of the 3rd Usenix Workshop on Electronic Commerce, Usenix, 1998. Full paper available below.
Full paper: Available as compressed postscript, postscript, or pdf. ( Help if this doesn't work).