Quantum Cryptography with 3-State Systems
Helle Bechmann-Pasquinucci, Asher Peres · Physical Review Letters · 2000
We consider quantum cryptographic schemes where the carriers of information are 3-state particles. One protocol uses four mutually unbiased bases and appears to provide better security than obtainable with 2-state carriers. Another possible method allows quantum states to belong to more than one basis. Security is not better, but many curious features arise.