Annual International Conference on the Theory and Applications of Cryptographic Techniques

EUROCRYPT 2005: Advances in Cryptology – EUROCRYPT 2005 pp 268-284

Computational Indistinguishability Between Quantum States and Its Cryptographic Application

  • Akinori Kawachi
  • Takeshi Koshiba
  • Harumichi Nishimura
  • Tomoyuki Yamakami
Conference paper

DOI: 10.1007/11426639_16

Volume 3494 of the book series Lecture Notes in Computer Science (LNCS)
Cite this paper as:
Kawachi A., Koshiba T., Nishimura H., Yamakami T. (2005) Computational Indistinguishability Between Quantum States and Its Cryptographic Application. In: Cramer R. (eds) Advances in Cryptology – EUROCRYPT 2005. EUROCRYPT 2005. Lecture Notes in Computer Science, vol 3494. Springer, Berlin, Heidelberg


We introduce a problem of distinguishing between two quantum states as a new underlying problem to build a computational cryptographic scheme that is ”secure” against quantum adversary. Our problem is a natural generalization of the distinguishability problem between two probability distributions, which are commonly used in computational cryptography. More precisely, our problem QSCDff is the computational distinguishability problem between two types of random coset states with a hidden permutation over the symmetric group. We show that (i) QSCDff has the trapdoor property; (ii) the average-case hardness of QSCDff coincides with its worst-case hardness; and (iii) QSCDff is at least as hard in the worst case as the graph automorphism problem. Moreover, we show that QSCDff cannot be efficiently solved by any quantum algorithm that naturally extends Shor’s factorization algorithm. These cryptographic properties of QSCDff enable us to construct a public-key cryptosystem, which is likely to withstand any attack of a polynomial-time quantum adversary.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Akinori Kawachi
    • 1
  • Takeshi Koshiba
    • 2
  • Harumichi Nishimura
    • 3
  • Tomoyuki Yamakami
    • 4
  1. 1.Graduate School of Information Science and EngineeringTokyo Institute of TechnologyTokyoJapan
  2. 2.Secure Computing LaboratoryFujitsu Laboratories Ltd.KawasakiJapan
  3. 3.ERATO Quantum Computation and Information ProjectJapan Science and Technology AgencyKyotoJapan
  4. 4.Computer Science ProgramTrent UniversityPeterboroughCanada