The Cocaine Auction Protocol:

On the Power of Anonymous Broadcast

Frank Stajano and Ross Anderson

Traditionally, cryptographic protocols are described as a sequence of steps, in each of which one principal sends a message to another. It is implicitly assumed that the fundamental communication primitive is necessarily one-to-one, and protocols addressing anonymity tend to resort to the composition of multiple elementary transmissions in order to frustrate traffic analysis.

This paper builds on a case study, of an anonymous auction between mistrustful principals with no trusted arbitrator, to introduce "anonymous broadcast" as a new protocol building block. This primitive is, in many interesting cases, a more accurate model of what actually happens during transmission. With certain restrictions it can give a particularly efficient implementation technique for many anonymity-related protocols.

Frank gave (an evolving version of) the Cocaine Auction talk on the following occasions:

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validated (recheck)