Simple quantum password checking
Juan Carlos García-Escartín, Pedro Chamorro‐Posada · Physical Review A · 2015
We present a quantum password checking protocol where secrecy is protected by the laws of quantum mechanics. The passwords are encoded in quantum systems that can be compared but have a dimension too small to allow reading the encoded bits. We study the protocol under different replay attacks and show it is robust even for poorly chosen passwords. We also describe a possible implementation with conventional optical elements.