Continuous-variable quantum authentication of physical unclonable keys: Security against an emulation attack
This work addresses security for quantum authentication systems, but it is incremental as it builds on a recently proposed protocol.
The paper tackles the security of a quantum authentication protocol using physical unclonable keys against emulation attacks, deriving a sufficient condition for security based on Holevo's bound and Fano's inequality, with results applicable to current technology parameters.
We consider a recently proposed entity authentication protocol, in which a physical unclonable key is interrogated by random coherent states of light, and the quadratures of the scattered light are analysed by means of a coarse-grained homodyne detection. We derive a sufficient condition for the protocol to be secure against an emulation attack, in which an adversary knows the challenge-response properties of the key, and moreover he can access the challenges during the verification. The security analysis relies on Holevo's bound and Fano's inequality, and suggests that the protocol is secure against the emulation attack for a broad range of physical parameters that are within reach of today's technology.