A user centric group authentication scheme for secure communication

Group Authentication Schemes (GAS) are methodologies developed to verify the membership of multiple users simultaneously. Numerous GAS methods have been explored in the literature and can be classified into three generations based on their underlying mathematical principles. First-generation GASs rely on polynomial interpolation and the multiplicative subgroup of a finite field. Second-generation GASs also employ polynomial interpolation but distinguish themselves by using elliptic curves over finite fields. While third-generation GASs offer a promising solution for scalable environments, they have limitations in certain applications. Such applications typically require identifying users participating in the authentication process. In the third-generation GAS, users can verify their credentials while remaining anonymous. However, user identification is necessary in various applications. In this study, we propose an improved version of third-generation GAS that uses inner product spaces and polynomial interpolation to resolve this limitation. We address the issue of preventing malicious actions by legitimate group members. The current third-generation scheme allows members to share group credentials, which can jeopardize group confidentiality. Our proposed scheme mitigates this risk by preventing individual users from distributing valid credentials. However, a potential limitation of our scheme is its reliance on a central authority for authentication in certain scenarios.