No-cloning principal can alone provide security

Existing quantum key distribution schemes need the support of classical authentication scheme to ensure security. This is a conceptual drawback of quantum cryptography. It is pointed out that quantum cryptosystem does not need any support of classical cryptosystem to ensure security. No-cloning principal can alone provide security in communication. Even no-cloning principle itself can help to authenticate each bit of information. It implies that quantum password need not to be a secret password. Ones name can be ones quantum password. In classical cryptography, a key is needed to encrypt secret message. In 1949, Shannon proved [1] that one-time-pad [2] is an unbreakable cryptosystem provided key is not reused. Still, one-time-pad system is not popular because always new key is required. Around 1970, Wisner first realized [3] that quantum no-cloning principle [4] could ensure security of data, although no-cloning principle was discovered later. In 1984, after the delayed publication of Wisner’s seminal work [3], Bennett and Brassard discovered [5] a quantum key distribution (QKD) protocol where two distant users can generate secure key without secretly sharing any key. Since then many QKD protocols have been designed [6]. QKD system will completely break down [7], if eavesdropper impersonates legitimate receiver. To do so, eavesdropper has to intercept the transmitted quantum states. To foil this simple attack [7], Wegman-Carter classical authentication protocol [8], where classical laws of probability provide