AB - 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. Due 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. © 2013 Authors, as per new IEEE copyright agreement. AU - Ying, M AU - Feng, Y AU - Yu, N DA - 2013/10/09 DO - 10.1109/CSF.2013.16 EP - 144 JO - Proceedings of the Computer Security Foundations Workshop PY - 2013/10/09 SP - 130 TI - Quantum information-flow security: Noninterference and access control Y1 - 2013/10/09 Y2 - 2026/08/10 ER -