ecash

For the anonymous bank operating through interfaces in the Tor network, see eCache.

Using cryptography, ecash was introduced by David Chaum as an anonymous electronic cash system. He used blind signatures to achieve unlinkability between withdrawal and spend transactions.^[1] Depending on the properties of the payment transactions, one distinguishes between on-line and off-line electronic cash. The first off-line e-cash system was proposed by Chaum and Naor.^[2] Like the first on-line method, it is based on RSA blind signatures.

In the United States, only one bank implemented ecash, the Mark Twain bank,^[3] and the system was dissolved in 1997 after the bank was purchased by Mercantile Bank, a large issuer of credit cards.^[4] Similar to credit cards, the system was free to purchasers, while merchants paid a transaction fee.

In Australia ecash was implemented by St.George Bank, but the transactions were not free to purchasers. In June 1998, ecash became available through Credit Suisse in Switzerland. It was also available from Deutsche Bank in Germany, Bank Austria, Finland's Merita Bank/Eunet, Sweden's Posten, and Den norske Bank of Norway.

"ecash" was a trademark of DigiCash, which went bankrupt in 1998, and was sold to eCash Technologies, which was acquired by InfoSpace in 2002.

See also

• Electronic money

References

1. ^ David Chaum, Blind signatures for untraceable payments, Advances in Cryptology - Crypto '82, Springer-Verlag (1983), 199-203. (PDF)
2. ^ Chaum, D., Fiat, A., and Naor, M. 1990. Untraceable electronic cash. In Proceedings on Advances in Cryptology (Santa Barbara, California, United States). S. Goldwasser, Ed. Springer-Verlag New York, New York, NY, 319-327. (PDF)
3. ^ Mark Twain Bank Launches Ecash
4. ^ DigiCash loses U.S. toehold

Literature

• Schneier, Bruce. Applied Cryptography, Second Edition, John Wiley & Sons, 1996. ISBN 0-471-11709-9 (Chapter 6.4)
• Richard A. Mollin: RSA and Public-key Cryptography. p. 143-148. 2002, ISBN 1584883383, 9781584883388.
• Goldwasser, S. and Bellare, M. "Lecture Notes on Cryptography". Summer course on cryptography, MIT, 1996-2001. pp. 233.

External links

• An introduction to ecash at the Wayback Machine (archived October 9, 1997)
• "Detecting Double-Spending" -(Hal Finney's introduction to Chaumian digital cash)