Secure Physical Auctions for the Non-Expert

Abstract

An auction is a simple way of selling and buying goods. Modern auction protocols often rely on complex cryptographic operations to ensure manifold security properties, for instance bidder-anonymity or bid-privacy, non-repudiation, fairness or public veriability of the result. This makes them dicult to understand for users who are not experts in cryptography. We propose two physical auction protocols inspired by Sako's cryptographic auction protocol. In contrast to Sako's protocol, they donot rely on cryptographic operations, but on physical properties of the manipulated mechanical objects to ensure the desired security properties. The rst protocol only uses standard oce material, whereas the second uses a special wooden box. We validate the security of our solutions using ProVerif.