Efficient Ciphertext Policy Attribute Based Encryption under Decisional Linear Assumption

We propose a new Ciphertext Policy Attribute Based Encryption (CP-ABE) scheme where access structures are defined by AND-Gates with wildcards. One major difference between our scheme and the existing ones is that we can use a single element to represent one attribute, while the previous schemes require three different elements to represent the three possible values (namely positive, negative, and wildcard) of an attribute. Our proposed scheme also achieves both constant-size ciphertext and constant number of decryption operations, and is proven secure under the standard Decision Linear Assumption. Copyright is held by the owner/author(s).