Gottesman and Chuang Quantum Digital Signature: Difference between revisions

** '''Key Distribution:''' The author suggests a few methods for key distribution. One of them is the assumption of a trusted third party who receives public keys from Sender, checks all the keys using [[SWAP Test]] and then if test is passed by each key sent, the trusted party distributes it to the recipients. A second method eliminates the requirement of a trusted third party and instead requires Sender to send two copies of each public key to each recipient, such that, in the end each recipient has 4M keys (2M public keys for each message bit). Both Buyer and Verifier perform Swap test on their supposedly identical copies of public keys. Then, if passed, Buyer sends one copy of his public key to the Verifier, who then performs the SWAP test between the received copy and his copy of public key.

*'''Messaging:''' Sender sends her message bit with the associated private keys to the Buyer. Buyer performs the map on the private key (quantum one way function takes the sent private key as input) and then compares the output thus generated with the public key received in the distribution stage. If the number of unmatched bits are below rejection threshold, the message is declared valid, else invalid. If the number of unmatched bits is below acceptance threshold, it is declared transferable, else not transferable.

==Properties==