An intercept-resend eavesdropper measures a random fraction of the photons in a BB84…
PHYSICS · Subjective · Fermi University Physics · Quantum Information & Technology · Quantum information theory and communication · Quantum information theory and communication
Quantum Information and Technology, Ch Quantum key distribution and quantum networks
Problem
An intercept-resend eavesdropper measures a random fraction f of the photons in a BB84 transmission, each in a randomly chosen basis, and resends the result, leaving the rest untouched. This attack produces a measured sifted quantum bit error rate Q=3%. Find f, and the expected fraction of sifted bits whose value Eve knows with certainty.