Bounds on Information and the Security of Quantum Cryptography
Abstract
Description
Strong attacks against quantum key distribution use quantum memories and quantum gates to attack directly the final key. In this paper we extend a novel security result recently obtained, to demonstrate proofs of security against a wide class of such attacks. To reach this goal we calculate information-dependent reduced density matrices, we study the geometry of quantum mixed states, and we find bounds on the information leaked to an eavesdropper. Our result suggests that quantum cryptography is ultimately secure.
11 pages, LaTex, 1 figure. Submitted to Physical Review Letters. This new version is much different from the previous (conference) version. It contains explicit calculations of the maximal information obtained by various eavesdropping attacks on the final key, and suggests that quantum key distribution is ultimately secure
11 pages, LaTex, 1 figure. Submitted to Physical Review Letters. This new version is much different from the previous (conference) version. It contains explicit calculations of the maximal information obtained by various eavesdropping attacks on the final key, and suggests that quantum key distribution is ultimately secure