Lower Bounds For Concurrent Zero Knowledge*

We consider zero knowledge interactive proofs in a richer, more realistic communication environment. In this setting, one may simultaneously engage in many interactive proofs, and these proofs may take place in an asynchronous fashion. It is known that zero-knowledge is not necessarily preserved in such an environment; we show that for a large class of protocols, it cannot be preserved. Any 4 round (computational) zero-knowledge interactive proof (or argument) for a non-trivial language L is not black-box simulatable in the asynchronous setting.

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Correspondence to Joe Kilian.

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* An abridge version of this work has appeared in [24].

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Kilian, J., Rackoff, C. & Petrank, E. Lower Bounds For Concurrent Zero Knowledge*. Combinatorica 25, 217–249 (2005). https://doi.org/10.1007/s00493-005-0014-6

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Mathematics Subject Classification (2000):

  • 68Q17
  • 68Q10
  • 68Q85