Secure Quantum Key Distribution with an Uncharacterized Source

摘要: We prove the security of Bennett-Brassard (BB84) quantum key distribution protocol for an arbitrary source whose averaged states are basis independent, a condition that is automatically satisfied if suitably designed. The proof based on observation that, to adversary, extraction process equivalent measurement in sigma-hatx performed pure sigma-hatz-basis eigenstate. dependence achievable length bit error rate same as established by Shor and Preskill [Phys. Rev. Lett. 85, 441 (2000)] perfect source, indicating defects efficiently detected protocol.