English

Round and Communication Balanced Protocols for Oblivious Evaluation of Finite State Machines

Cryptography and Security 2022-01-07 v2 Machine Learning

Abstract

We propose protocols for obliviously evaluating finite-state machines, i.e., the evaluation is shared between the provider of the finite-state machine and the provider of the input string in such a manner that neither party learns the other's input, and the states being visited are hidden from both. For alphabet size Σ|\Sigma|, number of states Q|Q|, and input length nn, previous solutions have either required a number of rounds linear in nn or communication Ω(nΣQlogQ)\Omega(n|\Sigma||Q|\log|Q|). Our solutions require 2 rounds with communication O(n(Σ+QlogQ))O(n(|\Sigma|+|Q|\log|Q|)). We present two different solutions to this problem, a two-party one and a setting with an untrusted but non-colluding helper.

Keywords

Cite

@article{arxiv.2103.11240,
  title  = {Round and Communication Balanced Protocols for Oblivious Evaluation of Finite State Machines},
  author = {Rafael Dowsley and Caleb Horst and Anderson C. A. Nascimento},
  journal= {arXiv preprint arXiv:2103.11240},
  year   = {2022}
}