Research On Attribute Based Encryption Scheme With Constant Cost Of Communication

The competition of cyberspaces has become sharper and more complicated with the boosting of the technology of computer network and the profound reform of the economic Globalization.Meanwhile,the demand of the application in new type of model of net also widely obtains attention of everybody,when the new form and service of network represented by mobile internet,internet of thing,cloud computing is prevailing.Now,the communication method of enterprises in cloud environment has been transformed from single user connected on the both sides into multi-users connected at least one side between the both communication sides.In practice life,many enterprises utilize third party cloud communication platform to hold a net meeting for drafting the plan of future task.However,as to these platform is open and transparent to service providers,while the third cloud communication is compromised,the attacker can arbitrarily eavesdrop the commercial confidential information of the enterprise,which uses the platform to communicate.At present,the implement of the most security communication adopts SSL/TKS protocols,which uses the method of encrypting the communication data to prevent it from being eavesdropped.However,the protocols with traditional encryption algorithm cannot solve the problem of security key distribution in high efficient way in network meeting.The main reason is that traditional encryption algorithm is the one to one encryption scheme,people need to repeatedly encrypt a session key by utilizing different public key of those man who want to get the session key to join the network meeting,if he wants to transfer the session key to others in security way.Furthermore,before encrypting the session key to others,these people should transfer their public key to the man,who executes encryption operation,thus will cause the cost of communication increasing.Aiming to the problem that how enterprise establishes security communication in an efficient method in cloud circumstance,this thesis exploits a new one to multi-user encryption algorithm to research depth,and achieves a new way of encrypting session key.The main contribution and innovation are constructed by following parties in this dissertation.1.Based on the framework of attribute based encryption algorithm,the dissertation proposes an attribute based encryption scheme with the constant cost of communication and revocation of permission of users.In comparison to the existed attribute based encryption,on the aspect of the cost of communication,the size of cipher-text,private key,system parameter is constant in our scheme,and on the aspect of administration of permission of users,we can revoke the permission of decryption session key of users.In addition,our scheme is based onattribute scoring system,which extends the ability that attribute based encryption algorithm tolerates information of users' identity.2.On the side of analysis of efficiency of communication and computation,we can get the conclusion that the efficiency of communication cost and computing cost of the scheme called attribute revocation in attribute based encryption with constant communication cost is lower than the most previous attribute based encryption scheme.3.Through the method of formal security proof model,the paper proves that our scheme contains two aspects of security ability,one is an indistinguishability against adaptive chosen ciphertext without random oracle model,and the other is a verification on permission of private key has unforgeability,no user posses the ability to forge a scoring group to deceive any node of subsidiary company of enterprise for an attribute set which contains a corresponding permission.4.In this dissertation,the scheme of the public key encryption on finite field has been implemented through basic mathematic knowledge of finite field in algebra,and the dissertation can fast encrypt session key trough utilizing the fast encryption scheme.