Oblivious NFA evaluation with an untrusted third party

• Main Author: Zhou, Haoran
• Other Authors: Tay Kian Boon
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Computer science and engineering::Data::Data encryption
• Online Access: https://hdl.handle.net/10356/162890
• Institution: Nanyang Technological University

Oblivious substring matching is a well-studied problem, with plentiful applications in scenarios with privacy-preservation requirements, e.g., genome matching, malicious code detection, etc. A natural generalization of oblivious substring matching is oblivious finite automata evaluation, which matches a wider collection of patterns than substrings. In this paper, we propose an efficient protocol for the oblivious evaluation of Non-deterministic finite Automata (NFA) with the help of an untrusted third party and extend the protocol to Non-deterministic Finite state transducers. We prove the security of the protocol against one corrupted party. We further experiment with such protocol on a pattern-matching task with its complexity.