Iterated group products and leakage resilience against NC1

  • Authors:
  • Eric Miles

  • Affiliations:
  • Northeastern University, Boston, MA, USA

  • Venue:
  • Proceedings of the 5th conference on Innovations in theoretical computer science
  • Year:
  • 2014

Quantified Score

Hi-index 0.00

Visualization

Abstract

We show that if NC1 ≠ L, then for every element α of the alternating group At, circuits of depth O(log t) cannot distinguish between a uniform vector over (At)t with product = α and one with product = identity. Combined with a recent construction by the author and Viola in the setting of leakage-resilient cryptography [STOC '13], this gives a compiler that produces circuits withstanding leakage from NC1 (assuming NC1 ≠ L). For context, leakage from NC1 breaks nearly all previous constructions, and security against leakage from P is impossible. We build on work by Cook and McKenzie [J. Algorithms '87] establishing the relationship between L = logarithmic space and the symmetric group St. Our techniques include a novel algorithmic use of commutators to manipulate the cycle structure of permutations in At.