Efficient Fine-Grained Data Sharing based on Proxy Re-encryption in IIoT

With the development of the industrial Internet of Things (IIoT), the amount of data generated by industrial manufacturing equipment will increase. To reduce the cost of data management while achieving secure data sharing, data owners generally upload the resulting ciphertexts to a cloud server after encrypting their data. Attribute-based encryption (ABE) is a valuable technology that implements fine-grained access control over shared information; however, its computational complexity is not suitable for resource-constrained IIoT devices, making it difficult to apply directly to an IIoT environment. To address this problem, we design a fine-grained data sharing scheme based on proxy re-encryption in IIoT. In the proposed scheme, data files are encrypted through an identity-based encryption and a data owner can authorize a semi-trusted proxy server to transform the ciphertext into an ABE ciphertext. This realizes fine-grained access control and decreases a data owner's computational cost in data sharing. In addition, the computational burden is outsourced to a cloud server, and users only need to perform simple computing operations. A formal security proof indicates the proposed scheme's selective chosen-plaintext attack security. Theoretical and experimental analyses illustrate that our construction is more efficient than previous schemes.