A Fair Protocol for Signing Contracts (Extended Abstract).

Michael Ben-Or Oded Goldreich Silvio Micali Ronald L. Rivest A Fair Protocol for Signing Contracts (Extended Abstract). 43-52 1985 conf/icalp/1985 ICALP db/conf/icalp/icalp85.html#Ben-OrGMR85 http://dx.doi.org/10.1007/BFb0015729