Research Of Quantum Key Distribution Protocols And Quantum Random Number Generator Protocols

Information security is of great significance in modern society.It concerns many aspects of life,especially some important industries like military and finical systems.Classical cryptosystems such as RSA,DES and AES,their security are based on the complexity of solving complicated mathematical problems.Now the classical cryp-tosystems are challenged since the fast development of quantum computation.Quantum key distribution(QKD)is one of the most practical technologies in quan-tum information science.Its security is based on fundamental quantum theory,such as uncertainty relation,quantum non-cloning,and quantum measurement theory.On the other hand,the one-time-pad(OPT)cipher is proved to be secure.Their combination guarantees the unconditional security of communication.After 30 years' study since B-B84 protocol,QKD has achieved breakthrough progress both in theory and experiment.Although QKD technology has been put into practice,the study of new protocols should not be underestimated.Different protocols may have different advantages and disadvantages.Having different protocols allows us to choose a better one in different situations.Besides,new protocols help us to better understand the foundations of QKD and quantum theory.Another practical technology provided by quantum information is quantum ran-dom number generator(QRNG).QRNGs exploit the intrinsic randomness in quantum processing.The random number generation rate of many QRNG schemes can be com-pared with classical RNGs.In some QRNG protocols,few assumptions can be made to generate genuine randomness.This dissertation focuses on my major research results in quantum key distribution protocols and quantum random number generation,arranged as follows:1.Ping-Pong protocol is a typical two-way QKD protocol.However,its security in lossy channel has not been proved for a long time.We proposed a modified Ping-Pong protocol,and proved its security in noisy and lossy.After the theoret-ical work,we implemented a proof-of-principle experiment of the protocol using entanglement photon source.2.Round-robin differential phase shift(RRDPS)is new influential protocol in QKD study.Its security is totally different from conventional QKD protocols.We de-velop a theory to estimate Eve's information on raw key bits in a quite different way from the original paper.Its secret key rate and achievable distance are both improved.Besides,a long distance RRDPS experiment with simplest setup is demonstrated.3.We proposed a quantum random number generation protocol which works in prepare-and-measure scenario with independent devices.This work provides a practical approach to quantum randomness generation in a scenario of trusted but error-prone devices.High noise and loss can be tolerated in this scheme.We verified this protocol using heralded single photon source.