Lightweight multi-departmental data sharing scheme based on consortium blockchain

Epidemiologically investigating, such as COVID-19, means navigating through tight schedules, urgent tasking, and heavy workloads, hence the need for multi-department cooperation. However, a large amount of survey data contains private information which must also be shared among multiple departments. Therefore, it is necessary to ensure the confidentiality, integrity and availability of epidemiological data. To address the above problems, we propose a lightweight multi-departmental data sharing scheme by combining ciphertext-policy attribute-based encryption on elliptic curve, certificateless signature and consortium chain technology. In our scheme, elliptic curves are introduced into the ciphertext-policy attribute-based encryption to achieve fine-grained access control of shared data in multiple departments. Each department administrator generates an anonymous identity for each data owner to achieve identity conditional privacy. Furthermore, the data owner, during submission, generates a signature based on the certificateless technology, which safeguards the integrity of the shared survey data and avoids certificate management and key escrow problems along with a batch verification algorithm to improve the signature verification efficiency. Finally, it adopts consortium chain to store the signature information to prevent signature data tampering and enable public integrity auditing. Theoretical analysis and simulation experiments show its significant advantages over related ones in computation and storage overhead.