A fully secure ciphertext-policy attribute-based encryption with a tree-based access structure

A new fully secure ciphertext-policy attributed based encryption (CP-ABE) scheme with high expressibity access policy is presented. Our CP-ABE scheme uses tree-based access structure which includes AND, OR, threshold and NOT gates which granted high degree of expressibility for encryptor to make an access policy. Moreover, our scheme achieves full security CP-ABE definition where any access structure can be chosen as the challenge ciphertext. The proposed CP-ABE uses composite bilinear groups and dual encryption paradigm to achieve full security CP-ABE definition. We argue that our CP-ABE scheme is secure and feasible.