Recovering keys in open networks

Abstract

Key recovery has been the subject of a lot of discussion, of much controversy and of extensive research. The widespread opinion of the research community, expressed in a technical report, written by well known experts, is that large-scale deployment of a key recovery system is essentially impossible. Despite this fact, key recovery might be needed at a corporate level, as a form of key management. The basic observation of the present paper is that cryptographic solutions that have been proposed so far, completely ignore the communication context. Surprisingly, static systems are put forward for key recovery at the network layer and solutions that require connections with a server are proposed at the application layer. We give two examples showing that it is possible to take advantage of the communication environment in order to design key recovery protocols that are better suited and more efficient.