International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Paper: Black-Box Concurrent Zero-Knowledge Requires $\tilde\Omega(\log n)$ Rounds

Authors:
Ran Canetti
Joe Kilian
Erez Petrank
Alon Rosen
Download:
URL: http://eprint.iacr.org/2001/051
Search ePrint
Search Google
Abstract: We show that any concurrent zero-knowledge protocol for a non-trivial language (i.e., for a language outside $\BPP$), whose security is proven via black-box simulation, must use at least $\tilde\Omega(\log n)$ rounds of interaction. This result achieves a substantial improvement over previous lower bounds, and is the first bound to rule out the possibility of constant-round concurrent zero-knowledge when proven via black-box simulation. Furthermore, the bound is polynomially related to the number of rounds in the best known concurrent zero-knowledge protocol for languages in $\NP$.
BibTeX
@misc{eprint-2001-11463,
  title={Black-Box Concurrent Zero-Knowledge Requires $\tilde\Omega(\log n)$ Rounds},
  booktitle={IACR Eprint archive},
  keywords={cryptographic protocols / zero-knowledge},
  url={http://eprint.iacr.org/2001/051},
  note={An extended abstract to appear in STOC01 alon@wisdom.weizmann.ac.il 11497 received 24 Jun 2001},
  author={Ran Canetti and Joe Kilian and Erez Petrank and Alon Rosen},
  year=2001
}