Quantum cryptography using any two nonorthogonal states
Abstract
Quantum techniques for key distribution-the classically impossible task of distributing secret information over an insecure channel whose transmissions are subject to inspection by an eavesdropper, between parties who share no secret initially-have been proposed using (a) four nonorthogonally polarized single-photon states or low-intensity light pulses, and (b) polarization-entangled or spacetime-entangled two-photon states. Here we show that in principle any two nonorthogonal quantum states suffice, and describe a practical interferometric realization using low-intensity coherent light pulses.
- Publication:
-
Physical Review Letters
- Pub Date:
- May 1992
- DOI:
- 10.1103/PhysRevLett.68.3121
- Bibcode:
- 1992PhRvL..68.3121B
- Keywords:
-
- 03.65.Bz;
- 42.50.Wm;
- 89.70.+c;
- Information theory and communication theory