This paper presents a perfectly secure key distribution scheme for dynamic conferences, where a group of users can compute a common secure key without being compromised by coalitions of up to k users. The scheme is designed to be non-interactive, meaning users compute the key without any communication. The paper establishes a lower bound on the size of the information each user must hold, which is shown to be optimal. It also considers an interactive model where users can communicate to reduce the amount of information needed. The scheme is extended to handle network topologies with constraints and applied to various scenarios, including authentication and hierarchical key distribution. The paper also discusses the theoretical foundations of the scheme using information theory, including entropy and mutual information. The results show that the scheme is secure against coalitions of up to k users and can be adapted to different network structures. The paper concludes with applications of the scheme in authentication and master key generation, demonstrating its practical relevance.This paper presents a perfectly secure key distribution scheme for dynamic conferences, where a group of users can compute a common secure key without being compromised by coalitions of up to k users. The scheme is designed to be non-interactive, meaning users compute the key without any communication. The paper establishes a lower bound on the size of the information each user must hold, which is shown to be optimal. It also considers an interactive model where users can communicate to reduce the amount of information needed. The scheme is extended to handle network topologies with constraints and applied to various scenarios, including authentication and hierarchical key distribution. The paper also discusses the theoretical foundations of the scheme using information theory, including entropy and mutual information. The results show that the scheme is secure against coalitions of up to k users and can be adapted to different network structures. The paper concludes with applications of the scheme in authentication and master key generation, demonstrating its practical relevance.