DAPIS: A Secure Proxy Re-encryption Protocol for Delegated Authentication and Privacy Management

The protection of personal data and the management of delegated authentication are major issues in distributed and connected environments, such as the Cloud and the Internet of Things (IoT). Current solutions, such as federated authentication systems, do not guarantee total confidentiality of personal data, exposing users to the risk of information leakage. In this article, we present DAPIS (Delegated Authentication and Personal Information Self-management), an innovative protocol based on the Proxy Re-encryption (PRE), which jointly solves the problems of delegated authentication and secure management of personal information. DAPIS ensures that user data remains encrypted, even for the Identity Provider (IdP), while offering users granular control over the information shared with services. The protocol also enables asynchronous and disconnected authentication, making it particularly suitable for constrained environments such as the IoT. A JavaScript implementation shows that the use of Elliptic Curve Cryptography (ECC) significantly optimizes protocol performance, making DAPIS both efficient and secure for real-world deployments.