Secure and efficient online data sharing scheme using broadcast encryption with personalised message system

In the healthcare industry, online data sharing has become increasingly important, but it also raises significant security concerns. To address these concerns, we propose a secure and efficient online data sharing scheme that uses a cryptographic primitive called broadcast encryption with personalised message system. This notion is applicable to many realistic broadcast services that supports IoT and cloud technology. Specifically, in our system, the data owner creates personalized data for each legitimate user in a group and then transmits a common encrypted data for the entire group in a way that completely hides the subscribed user set from outsiders. Only authorized users can recover personalised data, while all authorized consumers can decrypt the common data. Proposed scheme employs shamir secret sharing scheme to fairly distribute and reconstruct secret among various set up authority to prevent the insider attack from malicious setup authority.We highlight the security consideration in such a scenario and capture the security requirements in the security model. Subsequently, we present a concrete scheme, which is proven CPA secure under the decisional bilinear Diffie-Hellman exponent assumption. In addition, it uses asymmetric pairings whereas rest of the schemes used symmetric pairings, which in turn leads to the smaller and constant compact size ciphertext, constant decryption keys, reduced channel requirement, prevent fault attacks on symmetric bilinear map, and, enhanced performance.