Patent ID: 8391486

Claim:
A method for distributing a shared secure key between first and second parties (Alice and Bob), said first party having a mirror, said second party having an interferometer pair that includes first, second and third beam splitters, and first and second detectors, said first party possessing a transfer list of random binary values that constitutes a raw key, said method comprising: sending a plurality of photons from the second party (Bob) into the interferometer pair at the first beam splitter; performing a first weak measurement that incorporates a first coupling strength g 4 on each photon as |1 1| 1 being a first pointer result; incorporating said first pointer result into a first time-ordered list L 1 for said each photon; performing a second weak measurement that incorporates a second coupling strength g B by the first party (Alice) on said each photon that passes through the second beam splitter to the mirror as |1 1| 2 being a second pointer result; incorporating said second pointer result into a second time-ordered list L 2 for said each photon that passes through; recording identification as one of the first and second detectors at which said each photon arrives via the third beam splitter as respective first and second detector registrations; collecting said first and second detector registrations into a third time-ordered list F that correspond to said first time-ordered list L 1 as respective first and second detection lists B 1 and B 2 ; determining first and second averages of said respective first and second detection lists; and comparing said first and second averages to verify existence of a non-trivial difference that indicates secure key distribution status.