@device(postscript) @libraryfile(Mathematics10) @libraryfile(Accents) @style(fontfamily=timesroman,fontscale=11) @pagefooting(immediate, left "@c", center "@c", right "@c") @heading(Atomicity in Electronic Commerce) @heading(CMU-CS-96-112) @center(@b(J. Doug Tygar)) @center(January 1996@foot.) @center(FTP: CMU-CS-96-112.ps) @blankspace(1) @begin(text) There is a tremendous demand for the ability to electronically buy and sell goods over networks. Electronic commerce has inspired a large variety of work. Unfortunately, much of that work ignores traditional transaction processing concerns @y(M) chiefly atomicity. This paper discusses the role of atomicity in electronic commerce. It then briefly surveys some major types of electronic commerce pointing out flaws in atomicity. We pay special attention to the atomicity problems of proposals for digital cash. The paper presents two examples of highly atomic electronic commerce systems: NetBill and Cryptographic Postage Indicia. @blankspace(2line) @begin(transparent,size=10) @b(Keywords:@ )@c @end(transparent) @blankspace(1line) @end(text) @flushright(@b[(23 pages)])