Study On Certificateless Public Key Encryption And Its Application In Smart Grid AMI

Certificateless public key cryptography(CL-PKC)is a new type of public key cryptography,which is based on the identity-based cryptography(ID-PKC).CL-PKC hasn't have the key escrow problem and the need for public key certificate,which combines the advantages of ID-PKC and Certificate-based public key cryptography.In recent years,many certificateless public key encryption schemes have been published,but they neglect a more strong malicious KGC attack,the KGC maliciously generate the master public key and master private key pair at the beginning of system establishment,so that it may compromise the security of the certificateless cryptosystem.So how to design an effective CL-PKE scheme against the this malicious KGC attack become an important issue.This paper conducts the research on the certificateless public key encryption schemes,the main research works are as follows:1.Based on the Sakai-Kasahara IBE scheme,this paper propose an effective CL-PKE scheme against the malicious KGC attack,and prove the scheme's security in the random oracle model.The scheme includes 6 steps:System setup?User-key-generation?Partial-key-generation?Private-key-generation?Encrypt and Decrypt.In our scheme,polynomial user public key is an input of the Partial-key-generation,while it will be an important factor in Private-key-generation.Attacker eavesdrops the communication channel,intercepts the user partial key.However the random selected secret value(user secret holds)of user do not transmit via the communication channel,so the attacker cannot successfully calculate the user private key,also can not pretend to be legitimate users to decrypt ciphertext.If the KGC uses its malicious private key to decrypt user's ciphertext,user can provide its partial key and private key to prove malicious KGC attack,ensuring that the scheme can achieve the 3~rdd trust level(KGC and user have open communication channel).2.This paper applies our encryption scheme to key management of Smart Grid AMI(advanced metering infrastructure)and present a certificateless key management scheme.This paper first introduces the characteristics of AMI in the Smart Grid and the potential security risks,then introduces the research status of key management schemes in AMI,finally,applies the proposed CL-PKE to key management of Smart Grid AMI.We discuss the system initialization?the new node joining?private key update and node key revocation,analyze the security of the algorithm.This application effectively eliminates the key escrow problem and provides protection for the nodes'private key.It also overcomes the disadvantages of the dishonest nodes conspiring to get legal user's private key.The proposed key management scheme meets the security requirements of AMI and suits its system features,which is proved by performance analysis.This work means that our scheme applying to the Smart Grid AMI has practical significance.