Attribute-Based Online/Offline Encryption in Smart Grid

A smart grid is a modernized electrical grid that uses distribution networks to deliver electricity. It aims to gather and act on information, such as information about the behaviors of grid entities, in an automated fashion to improve the efficiency, security and reliability. It is important that the sensitive information should be shared securely among the grid entities. In smart grid, smart devices (e.g., smart meters) usually have limited computational capability. In this paper, we propose an online/offline attribute based encryption (ABE) scheme based J.Hur´s ABE scheme with hidden policy. In our scheme, the advantages of J.Hur´s scheme are kept. Thus, the data privacy and policy privacy are all preserved well. The computational overhead of encryptors are reduced by splitting the computation for encryption algorithm into two phases: online/offline. Most of the laborious decryption operations are delegated to the offline phase. The online phase can then rapidly assemble an ABE ciphertext when the message and the attribute control policy become known.