An efficient and secure data sharing in Smart Grid: Ciphertext-policy attribute-based signcryption

With the development of modern power systems, Smart Grid as the intelligent generation of electricity networks, has been faced with a tremendous attention. The Smart Grid systems are made up of fine-grained power grid measurements to achieve a high stability and reliability. In these networks, the data security and privacy issues for secure data sharing among the components of the system have emerged as the basic requirement. Typically, a service provider securely shares the data/commands with the smart meters under an arbitrary policy which is determined by the service providers. As the smart grid components are considered to have constrained computational resources, we cannot directly use the common cryptographic primitives, such as attribute-based encryption schemes, for data sharing. In this paper, we consider a communications model in which a delegated third party as the storage center with a powerful computational ability is determined to partially decrypt the shared ciphertexts and finally the authorized end users can decrypt the received messages. Then we propose an efficient attribute-based signcryption scheme in which the number of the required pairing is independent to the number of the attributes. Complexity comparison of our proposed scheme with the existing work shows the efficiency of our proposal.