Security of Quantum Key Distribution against All Collective Attacks

Abstract. Security of quantum key distribution against sophisticated attacks is among the most important issues in quantum information theory. In this work we prove security against a very important class of attacks called collective attacks (under a compatible noise model) which use quantum memories and gates, and which are directed against the final key. This work was crucial for a full proof of security (against the joint attack) recently obtained by Biham, Boyer, Boykin, Mor, and Roychowdhury [1].