Attribute-based Encryption Vehicle Network Information Transfer Program

In today's vehicular network security research, group communication is often used for information security. But traditional group communication has some disadvantages in VANETs because of the high mobility in vehicles. One on side, it would be huge cost to maintain group member management, and become unrealistic in real usage. On the other side, the formation of a group is restricted by many factors and lack of complex access control policies.Ciphcrtext-policy attribute-based encryption (CP-ABE) provides an encrypted access control mechanism for broadcasting messages. Basically, a sender encrypts a message with an access control policy tree which is logically composed of attributes; receivers are able to decrypt the message when their attributes satisfy the policy tree. A user's attributes stand for the properties that he currently owns. However, this is not easy in CP-ABE because whenever one attribute changes, the entire private key, which is based on all the attributes, must be changed.In this paper, firstly we separate dynamic attributes and static attributes in order to prove management. Secondly we introduce fading function, which renders attributes dynamic and allows users to update each attribute separately. At last, we study how choosing fading rate for fading function affects the efficiency and security. We also compare our design with CP-ABE and find our scheme performs significantly better under certain circumstance. Our scheme can provide a secure, reliable, flexible and efficient way to solve the communication problem in VANETs.