Attribute-based data access control scheme with secure revocation in fog computing for smart grid

Smart grid requires sharing sensitive data to external researchers. Attribute encryption is a common technique used in data sharing. Unfortunately, existing revocation mechanisms do not consider the following two issues. One is that the revoked user may save intermediate values computed in the past to illegally decrypt the updated cipher text. The other is that the update parameters of keys can be leaked to the revoked user, which leads to revocation failure. To address the above issues, we propose a verifiable outsourcing decryption and data sharing scheme, in which we introduce version parameters of ciphertexts and keys, and associate the update parameters of keys with each user to achieve security-enhanced revocation. In addition, a formal security proof is given under the DBDH assumption. Finally, we evaluate the performance of the scheme and the results show that the proposed scheme is more effective than current schemes.