Paper 2001/095

Secure Vickrey Auctions without Threshold Trust

Helger Lipmaa and N. Asokan and Valtteri Niemi

Abstract

We argue that threshold trust is not an option in most of the real-life electronic auctions. We then propose two new cryptographic Vickrey auction schemes that involve, apart from the bidders and the seller $S$, an auction authority $A$ so that unless $S$ and $A$ collude the outcome of auctions will be correct, and moreover, $S$ will not get any information about the bids, while $A$ will learn bid statistics. Further extensions make it possible to decrease damage that colluding $S$ and $A$ can do, and to construct $(m+1)$st price auction schemes. The communication complexity between the $S$ and $A$ in medium-size auctions is at least one order of magnitude less than in the Naor-Pinkas-Sumner scheme.

Note: Final version, the changes are minor and mainly cosmetical. More information on this paper is available at http://www.tcs.hut.fi/~helger/papers/lan02