An Atomicity-Generating Layer for Anonymous Currencies

1* Atomicity is a necessary element for reliable transactions (Financial Service Technology Consortium, 1995; Camp, Sirbu and Tygar, 1995; Tygar, 1996). Anonymity is also an issue of great importance not only to designers of commerce systems, (Chaum, 1982; Chaum, 1989; Chaum, Fiat & Naor, 1988; Medvinski, 1993), but also to those concerned with the societal effects of information technologies (Branscomb 1994. Compaine 1985, National Research Council 1996, Neumann 1993, Poole 1983). Yet there has been a tradeoff between these two elements in commerce system design. Reliable systems, which provide highly atomic transactions, offer limited anonymity (Visa, 1995; Sirbu and Tygar, 1995; Mastercard, 1995, Low, Maxemchuk and Paul, 1993) . Anonymous systems (Chaum, 1985; Chaum 1989; Medvinski, 1993) do not offer reliable transactions as shown in Yee, 1994; Camp, 1999; and Tygar, 1996. This work illustrates that any electronic token currency can be made reliable with the addition of this atomicity-generating layer. 1 * This work was begun at Carnegie Mellon University with support from the US Postal Service, and an equipment grant from IBM. This work is the opinion of the author and does not necessarily reflect the opinion of any funding agency, employer, or the US Government. I would like to acknowledge Michael Harkavey, Marvin Sirbu, Doug Tygar, and Bennet Yee.