Unconditional and composable security using a single stateful tamper-proof hardware token

Abstract

Cryptographic assumptions regarding tamper proof hardware tokens have gained increasing attention. Even if the tamper-proof hardware is issued by one of the parties, and hence not necessarily trusted by the other, many tasks become possible: Tamper proof hardware is sufficient for universally composable protocols, for information-theoretically secure protocols, and even allow to create software which can only be used once (One-Time-Programs). However, all known protocols employing tamper-proof hardware are either indirect, i.e., additional computational assumptions must be used to obtain general two party computations or a large number of devices must be used. In this work we present the first protocol realizing universally composable two-party computations (and even trusted One-Time-Programs) with information-theoretic security using only one single tamper-proof device issued by one of the mutually distrusting parties. © 2011 International Association for Cryptologic Research.