Coherent-pulse implementations of quantum cryptography protocols resistant to photon-number-splitting attacks
- Group of Applied Physics, University of Geneva, 20, rue de l'Ecole-de-Medecine, CH-1211 Geneva 4 (Switzerland)
We propose a class of quantum cryptography protocols that are robust against photon-number-splitting attacks (PNS) in a weak coherent-pulse implementation. We give a quite exhaustive analysis of several eavesdropping attacks on these schemes. The honest parties (Alice and Bob) use present-day technology, in particular an attenuated laser as an approximation of a single-photon source. The idea of the protocols is to exploit the nonorthogonality of quantum states to decrease the information accessible to Eve due to the multiphoton pulses produced by the imperfect source. The distance at which the key distribution becomes insecure due to the PNS attack is significantly increased compared to the existing schemes. We also show that strong-pulse implementations, where a strong pulse is included as a reference, allow for key distribution robust against photon-number-splitting attacks.
- OSTI ID:
- 20640589
- Journal Information:
- Physical Review. A, Vol. 69, Issue 1; Other Information: DOI: 10.1103/PhysRevA.69.012309; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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