Approximate Two-Party Privacy-Preserving String Matching with Linear Complexity

TL;DR

This paper introduces a linear-complexity, non-interactive, privacy-preserving string matching system that provides deterministic approximate results, suitable for cloud computing, and resistant to certain differential attacks.

Contribution

It presents a novel efficient approximate string matching protocol that is deterministic, non-interactive, and extends security against differential attacks.

Findings

System achieves linear complexity in string comparison.

Performance is comparable or superior to existing privacy-preserving algorithms.

Protocol resists iterated differential attacks.

Abstract

Consider two parties who want to compare their strings, e.g., genomes, but do not want to reveal them to each other. We present a system for privacy-preserving matching of strings, which differs from existing systems by providing a deterministic approximation instead of an exact distance. It is efficient (linear complexity), non-interactive and does not involve a third party which makes it particularly suitable for cloud computing. We extend our protocol, such that it mitigates iterated differential attacks proposed by Goodrich. Further an implementation of the system is evaluated and compared against current privacy-preserving string matching algorithms.