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

Ran Canetti; Joe Kilian; Erez Petrank; Alon Rosen

Paper 2001/051

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

Ran Canetti, Joe Kilian, Erez Petrank, and Alon Rosen

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 $\NP$.

Metadata

Available format(s): PS
Category: Cryptographic protocols
Publication info: Published elsewhere. An extended abstract to appear in STOC01
Keywords: zero-knowledge
Contact author(s): alon @ wisdom weizmann ac il
History: 2001-06-24: received
Short URL: https://ia.cr/2001/051
License: CC BY

BibTeX

@misc{cryptoeprint:2001/051,
      author = {Ran Canetti and Joe Kilian and Erez Petrank and Alon Rosen},
      title = {Black-Box Concurrent Zero-Knowledge Requires $\tilde\Omega(\log n)$ Rounds},
      howpublished = {Cryptology {ePrint} Archive, Paper 2001/051},
      year = {2001},
      url = {https://eprint.iacr.org/2001/051}
}