## Cryptology ePrint Archive: Report 2010/484

Automata Evaluation and Text Search Protocols with Simulation Based Security

Rosario Gennaro and Carmit Hazay and Jeffrey S. Sorensen

Abstract: This paper presents efficient protocols for securely computing the following two problems:

1) The fundamental problem of pattern matching. This problem is defined in the two-party setting, where party $P_1$ holds a pattern and party $P_2$ holds a text. The goal of $P_1$ is to learn where the pattern appears in the text, without revealing it to $P_2$ or learning anything else about $P_2$'s text. This problem has been widely studied for decades due to its broad applicability.

We present several protocols for several notions of security. We further generalize one of our solutions to solve additional pattern matching related problems of interest.

2) Our construction from above, in the malicious case, is based on a novel protocol for secure oblivious automata evaluation which is of independent interest. In this problem, party $P_1$ holds an automaton and party $P_2$ holds an input string, and they need to decide if the automaton accepts the input, without learning anything else.

Our protocol obtains full security in the face of malicious adversaries.

Category / Keywords: secure two-party computation, efficient protocols, full simulation-based security, text search

Publication Info: Full version of a PKC 2010 paper

Date: received 14 Sep 2010, last revised 6 Aug 2014

Contact author: carmit hazay at gmail com

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2010/484

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