The Security Analysis Of Quantum "SAGR04" Protocol In Collective-rotation Noise Channel

Twenty-first Century is the era of information explosion. With the vigorous development of the Internet, especially in recent years, the explosive development of mobile Internet, people's lives are more and more inseparable from the internet. The convenience of the Internet has brought people a lot of benefits, and make people's lives more exciting and rich.At the same time, Internet let people indulge in it and ignore the potential danger. A popular proverb on the Internet indicate the persent situation: the age of the Internet make all people "naked" in the network.In 2013, the "prism" of U.S. National Security Agency was reveal to the public, and also make the network security issues presented in front of people once again.On the one hand, When the network security is challenged,cryptography which determine the success or failure of network security has also been an unprecedented challenge. With the development of computing power, especially the development of quantum computers, the security of traditional cryptographic protocols is being challenged. On the other hand, with the development of quantum mechanics,the researchers found that some characteristics of quantum mechanics have unique advantages for secure communication. So quantum communication applications which is a cross discipline and formed by quantum mechanics and communication science emerges as the times require. The uncertainty principle and the non copy principle of quantum mechanics ensure that the security system based on quantum system has unconditional security. With the continuous efforts of researchers, there have been many new research achievements, such as quantum key distribution, quantum secure direct communication, quantum teleportation and quantum dense encoding which are relatively hot research topic in recent years.Quantum key distribution is mainly used to accomplish the task of generating secret key in secure communication. The One-time-pad has been proven to be absolutely secure for secure communication. For One-time-pad, the security of the key guarantees the security of the whole communication. Since the first quantum key distribution protocol was proposed in 1984, researchers have proposed many quantum key distribution protocols based on quantum mechanical properties and practical limitations. This paper studies the SAGR04 protocol which is one of the more prominents. Although the problem of eavesdropping has been fully considered in the SAGR04 protocol, it has neglected an important limitation in practical applications, which is the environmental noise. This paper chooses the joint rotation noise as the model, and focuses on the security of SAGR04 protocol in noisy environment. After our study, We found that the both sides of the SAGR04 protocol can effectively find Eve's eavesdropping by checking the error rate in the joint rotating noise environment. At the same time, in the premise of communication channel (which means the noise level less than 0.246),the communication can get absolute security through set the error rate threshold to 0.33 and below. In addition, this paper also studies the classical BB84 protocol and B92 protocol with the same noise processing method, and compares the results with the SAGR04 protocol. The results show that the SAGR04 protocol is better than both of them.