Quantum Information-Flow Security: Noninterference and Access Control

TL;DR

This paper introduces a formal automata model for analyzing information-flow security in quantum systems, extending classical noninterference concepts to quantum computing and establishing security proofs for quantum access control.

Contribution

It develops a quantum automata model and unwinding proof technique for noninterference, enabling rigorous security analysis of quantum information flow and access control.

Findings

Developed a quantum automata model for security analysis

Extended noninterference to quantum systems

Proved security of quantum access control mechanisms

Abstract

Quantum cryptography has been extensively studied in the last twenty years, but information-flow security of quantum computing and communication systems has been almost untouched in the previous research. Duo to the essential difference between classical and quantum systems, formal methods developed for classical systems, including probabilistic systems, cannot be directly applied to quantum systems. This paper defines an automata model in which we can rigorously reason about information-flow security of quantum systems. The model is a quantum generalisation of Goguen and Meseguer's noninterference. The unwinding proof technique for quantum noninterference is developed, and a certain compositionality of security for quantum systems is established. The proposed formalism is then used to prove security of access control in quantum systems.