Patent attributes
In methods and systems to authenticate systems in a quantum key distribution environment based on limited disclosures and identical, re-usable, pre-provisioned authentication keys, each system constructs an encryption key based on a corresponding one of transmitted events and detected events. Basis-sifting, error detection, error correction, and/or privacy amplification (PA) may be performed on the encryption keys based on limited disclosures (e.g., detection interval information, basis-sifting information, associated detection basis information, and/or parity measures). The authenticated keys may be modified based on disclosed detection information. Error detection and/or PA may be performed with identical pre-provisioned algorithms and pseudo-random values generated from the authenticated keys or modified authenticated keys. Final authenticated encryption keys are selectively constructed depending upon an extent of detected errors. Construction of authenticated encryption keys indicates authentication of the systems. None of the pre-provisioned authentication keys or modified authentication keys is disclosed and may thus be reused.