( Ciphertext Policy-Attribute Based Encryption with Non Monotonic Access Structures)

A ciphertext policy-attribute based encryption(CP-ABE) scheme can be used to realize access control mechanism without a trusted server. We propose an attribute-based access control mechanism by incorporating a CP-ABE scheme to ensure only authorized users can access the sensitive data. The idea of CP-ABE is to include access control policy in the ciphertexts, in which they can only be decrypted if a user possesses attributes that pass through the ciphertext's access structure. In this paper, we prove a secure CP-ABE scheme where the policy can be expressed in non-monotonic access structures. We further compare the performance of our scheme with the existing CP-ABE schemes