The Security Analysis of Quantum "SAGR04" Protocol in Collective-Rotation Noise Channel

Noise exists in the actual communication environment. It is necessary and significant to analyze the security of "SAGR04" protocol in the noise environment. An excellent model of collective rotation noise analysis is introduced and the discussing of the security of "SAGR04" protocol is based on the method of information theory. The eavesdropping can be detected for the increment of the qubit error rate and eavesdropper can maximally get about 50% of the keys. It can be concluded that the "SAGR04" protocol, used as quantum key distribution, is secure.