Use of small-scale quantum computers in cryptography with many-qubit entangled states

  • K. V. Bayandin
  • G. B. Lesovik
Quantum Information Science


We propose a new cryptographic protocol. It is suggested to encode information in ordinary binary form into many-qubit entangled states with the help of a quantum computer. A state of qubits (realized, e.g., with photons) is transmitted through a quantum channel to the addressee, who applies a quantum computer tuned to realize the inverse unitary-transformation decoding of the message. Different ways of eavesdropping are considered, and an estimate of the time needed for determining the secret unitary transformation is given. It is shown that using even small quantum computers can serve as a basis for very efficient cryptographic protocols. For a suggested cryptographic protocol, the time scale on which communication can be considered secure is exponential in the number of qubits in the entangled states and in the number of gates used to construct the quantum network.

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  1. 1.
    R. Feynman, Int. J. Theor. Phys. 21, 467 (1982).MathSciNetGoogle Scholar
  2. 2.
    D. Deutsch, Proc. R. Soc. London, Ser. A 400, 97 (1985).ADSzbMATHMathSciNetGoogle Scholar
  3. 3.
    P. W. Shor, SIAM J. Comput. 26, 1484 (1997).CrossRefzbMATHMathSciNetGoogle Scholar
  4. 4.
    R. Rivest, A. Shamir, and L. Adleman, Technical Report MIT/LCS/TR-212 (MIT Laboratory for Computer Science, 1979).Google Scholar
  5. 5.
    The Physics of Quantum Information, Ed. by D. Bouwmeester, A. Ekert, and A. Zeilinger (Springer, Berlin, 2000; Postmarket, Moscow, 2002).Google Scholar
  6. 6.
    C. H. Bennet and G. Brassard, in Proceedings of IEEE International Conference on Computer Systems and Signal Processing (IEEE, New York, 1984).Google Scholar
  7. 7.
    C. H. Bennet et al., J. Cryptology 5, 3 (1992).Google Scholar
  8. 8.
    A. Muller, J. Breguet, and N. Gisin, Europhys. Lett. 23, 383 (1993).ADSGoogle Scholar
  9. 9.
    A. K. Ekert et al., Phys. Rev. Lett. 69, 1293 (1992).CrossRefADSGoogle Scholar
  10. 10.
    J. F. Clauser, M. A. Horne, A. Shimony, and R. A. Hol, Phys. Rev. Lett. 23, 880 (1969).CrossRefADSGoogle Scholar
  11. 11.
    G. M. D’Ariano, L. Maccone, and M. Paini, quant-ph/0210105.Google Scholar
  12. 12.
    W. H. Press, S. A. Teukolsky, W. T. Veterlingt, and B. P. Flannery, The Art of Scientific Computing (Cambridge Univ. Press, Cambridge, 1988–1992), Chaps. 7.6 and 7.8.Google Scholar
  13. 13.
    M. H. Devoret, A. Wallraff, and J. M. Martinis, cond-mat/0411174.Google Scholar
  14. 14.
    Cavity Quantum Electrodynamics, Advances in Atomic, Molecular and Optical Physics, Ed. by P. Berman (Academic, New York, 1994), Suppl. 2; S. Haroche, in Fundamental Systems in Quantum Optics: Les Houche Summer School Session LIII, Ed. by J. Dalibard, J. M. Raimond, and J. Zinn-Justin (North-Holland, Amsterdam, 1992).Google Scholar
  15. 15.
    J. I. Cirac and P. Zoller, Phys. Rev. Lett. 74, 4091 (1995); J. F. Poyatos, J. I. Cirac, and P. Zoller, Phys. Rev. Lett. 81, 1322 (1998).CrossRefADSGoogle Scholar
  16. 16.
    N. A. Gershenfeld and I. L. Chuang, Science 275, 350 (1997).CrossRefMathSciNetGoogle Scholar
  17. 17.
    A. Ekert and R. Jozsa, Rev. Mod. Phys. 68, 733 (1996).CrossRefADSMathSciNetGoogle Scholar
  18. 18.
    W. K. Wootters and W. H. Zurek, Nature 299, 802 (1982).CrossRefADSGoogle Scholar
  19. 19.
    S. N. Molotkov and S. S. Nazin, quant-ph/0106046.Google Scholar
  20. 20.
    R. J. Schoelkopf et al., Nature 431, 162 (2004).ADSGoogle Scholar
  21. 21.
    V. Cerletti, O. Gywat, and D. Loss, cond-mat/0411235.Google Scholar
  22. 22.
    E. Knill and R. Laflamme, Phys. Rev. A 55, 900 (1997).CrossRefADSMathSciNetGoogle Scholar

Copyright information

© Pleiades Publishing, Inc. 2005

Authors and Affiliations

  • K. V. Bayandin
    • 1
  • G. B. Lesovik
    • 1
  1. 1.Landau Institute for Theoretical PhysicsRussian Academy of SciencesMoscowRussia

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