Quantum cryptography with imperfect apparatus

D. Mayers, A. Yao
Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280)  
Quantum key distribution, first proposed by Bennett and Brassard, provides a possible key distribution scheme whose security depends only on the quantum laws of physics. So far the protocol has been proved secure even under channel noise and detector faults of the receiver, but is vulnerable if the photon source used is imperfect. In this paper we propose and give a concrete design for a new concept, self-checking source, which requires the manufacturer of the photon source to provide certain
more » ... sts; these tests are designed such that, if passed, the source is guaranteed to be adequate for the security of the quantum key distribution protocol, even though the testing devices may not be built to the original specification. The main mathematical result is a structural theorem which states that, for any state in a Hilbert space, if certain EPR-type equations are satisfied, the state must be essentially the orthogonal sum of EPR pairs.
doi:10.1109/sfcs.1998.743501 dblp:conf/focs/MayersY98 fatcat:y7ps6mgmxbd6lbkw4kbfyst7my