Research On Broadcast Encryption Scheme Based On Chinese National Standard SM9 And Construction Of Simulation Platform

In the information industry,the protection for data security and personal privacy has been a longstanding and ongoing hot topic of concern,and the utilization of cryptographic techniques is one of the important ways to effectively ensure this issue is addressed.Broadcast encryption is a special encryption technology mainly used to achieve information broadcasting in a multi-recipient environment.The broadcast encryption technology not only ensures that the information can only be accessed by authorized recipients,but also avoids the repetitive labor and resource waste of multiple encryption,thereby improving efficiency.Due to the characteristic of one-to-many communication between broadcast encryption,it has applications of many fields such as multimedia,Internet of Things,and blockchain.Currently,various broadcast encryption schemes have been designed according to different practical needs.In recent years,with the formal implementation of the "Cryptography Law of the People’s Republic of China",there has been a lot of research on the localization of cryptographic algorithms in China.The identity-based cryptographic algorithm SM9 is a domestically designed cryptographic algorithm.Domestic researchers have designed many localizations cryptographic schemes based on the SM9 algorithm.However,research on broadcast encryption algorithms based on SM9 is not sufficient,and there is a lack of research on the chosen ciphertext attack indistinguishability,anonymity,and attribute-based schemes,which is not conducive to promoting China’s strategic requirements for independent and controllable cryptographic technology.This thesis mainly focuses on the research of the chosen ciphertext attack indistinguishability,anonymity,and attribute-based scheme for broadcast encryption based on the SM9 algorithm.The following research achievements have been made:(1)A chosen ciphertext attack security identity-based broadcast encryption scheme based on SM9,called SM9-CCA2-IBBE,has been designed using an internal verification method.This scheme achieves chosen ciphertext attack security under the random oracle model.The security and performance of the proposed scheme is analyzed.In the security analysis,the analysis method of Liu et al.be improved,and it is proven that the scheme satisfies IND-sIDCCA2 security under the random oracle model.In the performance analysis,the errors in Park et al.’s analysis of the Delerablee scheme is pointed out,and it is shown that the proposed scheme has certain desirable characteristics and is usable.(2)An anonymous identity-based broadcast encryption scheme based on SM9,called SM9-AIBBE,has been designed.This scheme achieves IND-nID-CCA2 security and ANOID-CCA2 security under the random oracle model based on SM9 for the first time.The anonymity of the scheme relies on reusing random numbers.A formal analysis process is provided for the security of the proposed scheme.Performance analysis shows that the scheme has good security and desirable characteristics,i.e.,the lengths and computation costs of the main public key,main private key,and receiver’s private key are constant,and the decryption computation cost is also constant.(3)A key-policy attribute-based broadcast encryption scheme based on SM9,called SM9KP-ABBE,has been designed.This scheme has the advantages of attribute-based encryption and can directly revoke legitimate receivers.The scheme uses a linear secret sharing scheme to construct an access structure,which can realize any access policy.The proposed scheme satisfies IND-selective-CPA security under the random oracle model,and a formal analysis process is provided.Performance analysis shows that the scheme has excellent performance and constant ciphertext length.(4)Finally,simulation platforms were built for the three encryption schemes,which could respectively to implement the encryption and decryption of plaintext information using the three encryption schemes and facilitate the statistical analysis of various performance data onto the encryption schemes,thus reflecting the practical value of the encryption schemes.This also enriched the CloudCrypto project led by Dr.Weiran Liu at Beihang University.