On the composition of authenticated byzantine agreement

A fundamental problem of distributed computing is that of simulating a secure broadcast channel, within the setting of a point-to-point network. This problem is known as Byzantine Agreement (or Generals) and has been the focus of much research. Lamport et al. showed that in order to achieve Byzantine Agreement in the standard model, more than 2/3 of the participating parties must be honest. They further showed that by augmenting the network with a public-key infrastructure for digital signatures, it is possible to obtain protocols that are secure for any number of corrupted parties. The problem in this augmented model is called "authenticated Byzantine Agreement". In this paper we consider the question of concurrent, parallel and sequential composition of authenticated Byzantine Agreement protocols. We present surprising impossibility results showing that:

• Type: Conference
• Year: 2002
• Where: STOC
• Authors: Yehuda Lindell, Anna Lysyanskaya, Tal Rabin
• Keywords: Algorithms, Authenticated Byzantine Agreement, Byzantine Agreement, Secure Broadcast Channel, STOC 2002