Helger Lipmaa N. Asokan Valtteri Niemi Secure Vickrey Auctions without Threshold Trust. 87-101 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2357&spage=87 2002 conf/fc/2002 Financial Cryptography db/conf/fc/fc2002.html#LipmaaAN02