SECRECY CAPACITY IN THE BB84 PROTOCOL OF QUANTUM CRYPTOGRAPHY

摘要

I calculate the secrecy capacity of the BB84 protocol in the presence of an individual attack in which the eavesdropping probe is entangled with the signal states, and States of the probe become correlated with the states measured by the legitimate receiver. Emphasis is placed on information leakage to the eavesdropping probe. The calculation generalizes earlier work to include an arbitrary angle between the signal bases.