Secure, Selective Group Broadcast in Vehicular Networks Using Dynamic Attribute Based Encryption
Ciphertext-Policy Attribute Based Encryption (CPABE) 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 current has. It is required for a user to keep his attributes up-to-date. 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.