Electronic Cash
- Paul Lorenz
As an increasing percentage of commerce occurs electonically, cash is becoming rare and may even someday no longer exist. While the electronic payment and money transfer mechansims of today have advantages over cash, such as convenience, it also has some issues. Though automated tracking of money movement, including source, destination and amount, may be convient at times, it also has serious privacy implications, be it for the possibility of governmental or corporate abuse. To address this, the notion of anonymous electronic cash has been introduced. The paper covers several basic techniques including blinding and cut-and-choose in the context of the original protocols by Chaum. It also covers an example of a new application of e-cash, micro-payments, using one-way function chains.
Paper is now available (.sxw) (.pdf)
References
[1] D. Chaum, "Blind Signatures for untraceable payments," In Advances in Cryptology-Proc. of CRYPTO '82, Plenum Press, 1983, pp. 199-203

[2] D. Chaum, A. Fiat, M. Noar, "Untraceable electronic cash", In Advances of Cryptology-Proc. of CRYPTO '88, LNCS 403, Springer-Verlag, 1988, pp. 319-327

[3] H. Peterson, G. Poupard, "Efficient scalable fair cash with off-line extortion prevention," (Technical Report, ENS, 33 pages, 1997), short version in Procceedings of International Conference on Information and Communication Security (ICICS' 97), LNCS 1334, Springer-Verlag, 1997, pp. 463-477

[4] R. Tracz, K. Wrona, "Fair Electronic Cash Withdrawal and Change Return for Wireless Networks", In Proceedings of the 1st ACM International Workshop on Mobile Commerce (Rome, Italy, July 2000), ACM, New York pp 14-19.