Multi-authority attribute-based encryption scheme from LWE problem

Most ABE schemes are based on bilinear maps, which leads to a high cost of storage and communication, and which cannot resist quantum attacks. Thus, we propose an LWE-based multi-authority attribute-based encryption scheme. In this scheme, there are different attribute authorities which can manage different attribute sets and generate privacy keys for the users. It can ensure the safety and improve the efficiency of the system. In addition, the Shamir secret-sharing schemes technology is introduced to construct the access tree structure which can support “and”, “or” and “threshold” operations of attributes with a high flexibility. Besides, we use the lattice theory and the basis delegation without a dimension increase algorithm in our scheme, which can not only increase the speed of encryption and decryption, but can also reduce the storage cost of the user′s private key and ciphertext. Lastly, the scheme is proved to be secure against the chosen plaintext attack under the standard model. Compared with the existing related schemes, our scheme can improve prominently the flexibility of the access policy, and it also can achieve a better system performance. Therefore, our scheme is more effective in the large scale distributed environment.