SHORT DISTANCE APPLICATIONS OF QUANTUM CRYPTOGRAPHY

We present an identification protocol based on quantum mechanics. The first user, Alice, needs to identify herself in front of a second user, Bob, by means of a password, known only to both. The safety requirement for Alice is that somebody impersonating Bob, who only pretended to know Alice's password, shall not be able to obtain information on the password from the exchange. This is an example of a potentially practical new application of quantum mechanics to cryptography.