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Calling Out Cheaters: Covert Security with Public Verifiability

  • Gilad Asharov
  • Claudio Orlandi
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7658)

Abstract

We introduce the notion of covert security with public verifiability, building on the covert security model introduced by Aumann and Lindell (TCC 2007). Protocols that satisfy covert security guarantee that the honest parties involved in the protocol will notice any cheating attempt with some constant probability ε. The idea behind the model is that the fear of being caught cheating will be enough of a deterrent to prevent any cheating attempt. However, in the basic covert security model, the honest parties are not able to persuade any third party (say, a judge) that a cheating occurred.

We propose (and formally define) an extension of the model where, when an honest party detects cheating, it also receives a certificate that can be published and used to persuade other parties, without revealing any information about the honest party’s input. In addition, malicious parties cannot create fake certificates in the attempt of framing innocents.

Finally, we construct a secure two-party computation protocol for any functionality f that satisfies our definition, and our protocol is almost as efficient as the one of Aumann and Lindell. We believe that the fear of a public humiliation or even legal consequences vastly exceeds the deterrent given by standard covert security. Therefore, even a small value of the deterrent factor ε will suffice in discouraging any cheating attempt.

Keywords

Signature Scheme Commitment Scheme Oblivious Transfer Honest Party Malicious Adversary 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. [AL07]
    Aumann, Y., Lindell, Y.: Security Against Covert Adversaries: Efficient Protocols for Realistic Adversaries. In: Vadhan, S.P. (ed.) TCC 2007. LNCS, vol. 4392, pp. 137–156. Springer, Heidelberg (2007)CrossRefGoogle Scholar
  2. [BCNP04]
    Barak, B., Canetti, R., Nielsen, J.B., Pass, R.: Universally composable protocols with relaxed set-up assumptions. In: FOCS, pp. 186–195. IEEE Computer Society (2004)Google Scholar
  3. [Can00]
    Canetti, R.: Security and composition of multiparty cryptographic protocols. J. Cryptology 13(1), 143–202 (2000)MathSciNetzbMATHCrossRefGoogle Scholar
  4. [DGN10]
    Damgård, I., Geisler, M., Nielsen, J.B.: From Passive to Covert Security at Low Cost. In: Micciancio, D. (ed.) TCC 2010. LNCS, vol. 5978, pp. 128–145. Springer, Heidelberg (2010)CrossRefGoogle Scholar
  5. [FY92]
    Franklin, M.K., Yung, M.: Communication complexity of secure computation (extended abstract). In: STOC, pp. 699–710 (1992)Google Scholar
  6. [GMS08]
    Goyal, V., Mohassel, P., Smith, A.: Efficient Two Party and Multi Party Computation Against Covert Adversaries. In: Smart, N.P. (ed.) EUROCRYPT 2008. LNCS, vol. 4965, pp. 289–306. Springer, Heidelberg (2008)CrossRefGoogle Scholar
  7. [Gol04]
    Goldreich, O.: Foundations of Cryptography, Basic Applications, vol. 2. Cambridge University Press (2004)Google Scholar
  8. [HL08]
    Hazay, C., Lindell, Y.: Efficient Protocols for Set Intersection and Pattern Matching with Security Against Malicious and Covert Adversaries. In: Canetti, R. (ed.) TCC 2008. LNCS, vol. 4948, pp. 155–175. Springer, Heidelberg (2008)CrossRefGoogle Scholar
  9. [HL10]
    Hazay, C., Lindell, Y.: Efficient secure two-party protocols: Techniques and constructions. Springer (2010)Google Scholar
  10. [IKNP03]
    Ishai, Y., Kilian, J., Nissim, K., Petrank, E.: Extending Oblivious Transfers Efficiently. In: Boneh, D. (ed.) CRYPTO 2003. LNCS, vol. 2729, pp. 145–161. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  11. [LP09]
    Lindell, Y., Pinkas, B.: A proof of security of yao’s protocol for two-party computation. J. Cryptology 22(2), 161–188 (2009)MathSciNetzbMATHCrossRefGoogle Scholar
  12. [MNPS04]
    Malkhi, D., Nisan, N., Pinkas, B., Sella, Y.: Fairplay - secure two-party computation system. In: USENIX Security Symposium, pp. 287–302 (2004)Google Scholar
  13. [PVW08]
    Peikert, C., Vaikuntanathan, V., Waters, B.: A Framework for Efficient and Composable Oblivious Transfer. In: Wagner, D. (ed.) CRYPTO 2008. LNCS, vol. 5157, pp. 554–571. Springer, Heidelberg (2008)Google Scholar

Copyright information

© International Association for Cryptologic Research 2012

Authors and Affiliations

  • Gilad Asharov
    • 1
  • Claudio Orlandi
    • 2
  1. 1.Department of Computer ScienceBar-Ilan UniversityIsrael
  2. 2.Department of Computer ScienceAarhus UniversityDenmark

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