Digital cash references

I got asked what would be good survey articles on digital cash. Two good ones that are widely available are both by David Chaum: Scientific American, August 1992, p. 96; and Communications of the ACM, October 1985, p. 1030. Unfortunately, neither of these really describes the mathematics, instead discussing things in terms of analogies. To get more details you have to read the conference proceedings. Many of the recent Eurocrypt and Crypto conferences have discussed implementations of digital cash. Hal Finney hfinney@shell.portal.com