Protecting personal data has become a major issue of concern in the whole world. As per the General Data Protection Regulation (GDPR), Data Owners (DO) are given back control over their data, which is maintained by the Service Providers (SP). However, SP needs to be fully GDPR compliant. In the existing GDPR enforcement technologies, DO is severely facing the scalability issue considering it has to manage separate keys for different data. Clearly, it would be highly impractical to manage such a huge and proportionally increased amount of keys for resource constrained devices of DO. Furthermore, the integrity of the data received by the Data User (DU) is not addressed in the existing works. We propose a proxy re-encryption based secure protocol where DO has to manage only one key. We propose a threat model to analyze our proposed protocol. In this analysis, we use a random oracle model to assess security and privacy. We use Burrows-Abadi-Needham (BAN) logic to verify the correctness. Simulation through AVISPA and ProVerif, formal verification tools, also confirms the security and privacy of the proposed protocol. A testbed simulation is conducted to estimate the computational, communication, and storage requirements, ensuring the practicality of the proposed protocol.

In n-party Computation, data from different sources are integrated to achieve a common goal, which can be beneficial for different applications. However, this goal may be at risk due to the fact that this corresponding data can be the target of attacks from outside attackers as well as inside ones. On the other hand, in Secure n-party Computation, the data can be processed by preserving security and privacy in such a way that no party can know the data of the others. Several schemes have been proposed to address the issues regarding n-party computation. However, some of them are not efficient in terms of computation and communication, or some of them have used a Trusted Initializer (TI), a third party, which is considered as trusted, for communicating between different parties. Therefore, to address these issues, we propose an n-party secure computation protocol without using any Trusted Initializer (TI). We formally simulate our protocol using Automated Verification of Internet Security Protocols and Applications (AVISPA) as well as we elaborate on the formal and informal security analysis of our proposed protocol. Performance analysis of our proposed protocol is also carried out and it is observed our proposed protocol is secure and protects the privacy of the system.