Efficient Offline Electronic Checks (Extended Abstract).

David Chaum Bert den Boer Eugène van Heyst Stig Fr. Mjølsnes Adri Steenbeek Efficient Offline Electronic Checks (Extended Abstract). 294-301 http://link.springer.de/link/service/series/0558/bibs/0434/04340294.htm 1989 EUROCRYPT db/conf/eurocrypt/eurocrypt89.html#ChaumBHMS89