Research On Collaborative Generation Of SM9 Private Key And Collaborative Calculation Of Cryptography

With the rapid development of the information age,IBC cryptosystem is more and more widely used in mobile applications,Io T,edge computing,industrial networks,wireless sensor networks and other aspects.For the IBC cryptosystem and its related applications,the security of the system's master private key and user's private key is very important.The leakage of the private key will directly lead to the loss of the security of the whole system.Therefore,how to protect the master private key and user's private key is of great significance in enhancing the security of IBC system.SM9 is a class of IBC schemes based on bilinear mapping(pairing),published by the State Cryptography Administration of P.R.China.All the research work in this thesis is focused on the security protection of SM9 private key.The main research work includes the collaborative generation of SM9 private key and SM9 collaborative calculation of cryptography.Among them,the collaborative generation of SM9 private key method splits the system's master key,mainly aiming at the security protection of the system's master private key;while the related research of SM9 collaborative calculation of cryptography is based on the secret sharing technology to protect the user's private key.Because of its unique operation mode of SM9 algorithm,the common secret sharing mode is not suitable for SM9 algorithm,so a safe and effective secret sharing scheme suitable for SM9 algorithm is of great significance in SM9 key protection.In the thesis,the two research works are aimed at different needs and application scenarios,and both of them use homomorphic encryption technology,and the specific research work is as follows:(1)During the research of the collaborative generation of SM9 private key method,the process of KGC's generation of the master key and the risk of master key leakage were analyzed,and the method of further improving the security of the master key was researched by using homomorphic encryption technology.Two private key generators(PKGs)shares the master key,and the leakage of one PKG's secret will not lead to the leakage of the entire master key and achieve the purpose of spreading risks.At the same time,the generation algorithm of user's private key in SM9 algorithm is studied,and the possible needs for customers of public IBC service providers are analyzed: that is,customers do not want their private keys to be completely generated by the provider,but they can also participate in the generation process of private key.So a collaborative generation of SM9 private key method is proposed.(2)In the research process of SM9 collaborative calculation of cryptography,the generation process of user's SM9 private key and the risk of user's private key management are analyzed.Taking user's signature private key as an example,how to generate SM9 digital signature without directly using user's signature private key is studied.In order to solve the problem that the usual secret sharing scheme is not suitable for SM9 algorithm,a safe and effective scheme of SM9 digital signature collaborative generation is proposed.(3)The SM9 private key generation system is designed and implemented according to the proposed collaborative generation scheme of SM9 private key,and the SM9 collaborative cryptography calculation system is designed and implemented according to the proposed collaborative generation scheme of SM9 digital signature.The correctness and security of all schemes are derived and verified in detail.