LWE-based multi-authority attribute-based encryption scheme with hidden policies

摘要

Most attribute-based encryption schemes are based on bilinear maps, which have large computational and storage overhead and cannot resist quantum attacks. In view of the above problems, a LWE-based multi-authority attribute-based encryption scheme with hidden policies is proposed. Firstly, the scheme uses the lattice theory to replace the previous bilinear maps, and supports multi-authority to manage different attribute sets. Secondly, the Shamir secret sharing mechanism is introduced to construct the access tree structure, which improves the flexibility of the system. Also, the access policies can be completely hidden so as to protect the privacy of users. Finally, the scheme is proved to be secure against the chosen plaintext attack under the standard model. Compared with the existing related schemes, the size of public parameters, master secret key, user's private key and cipher-text are all optimised in some degree. Therefore it is more suitable for data encryption in cloud environment.