A variant of BB84 Protocol based on quantum phase

One of the research focuses of quantum cryptography is the variants of BB84 protocol. This paper presents a variant of BB84 protocol based on quantum phase which employs two pairs of phase bases and four measurement operations. Then two different generation and measurement of quantum phases are discussed which lead to different shared keys and error probabilities introduced by the eavesdropper. The variant proposed by this paper is valuable to the research of quantum cryptography.