Scalable and Secure Group Key Agreement for Cloud Data Sharing Using Combinatorial Block Design

To ensure data security and access control for data sharing in the cloud, a secure and efficient group key agreement is necessary. This paper proposes an original block design-based key agreement scheme to support secure group data exchange. In a more technical sense, the protocol uses ideas from combinatorial block design to derive secure, collision-resistant key structures for group members with the property that only those who are supposed to possess the correct keys will be able to successfully decode shared information. It leverages the underlying algebraic properties of the associated large block designs to simplify key management and to alleviate the computational overhead in the context of dynamic group membership. The proposed method allows for fast addition/removal of members and minimal re-keying, making it more scalable and practical for large groups. The security analysis confirms the strength of the protocol toward common attacks like eavesdropping, and collusion attacks. The experimental results show that it is effective in reducing the complexity of key management and in improving the efficiency of data exchange within cloud systems. It offers a resilient and scalable approach for secure group collaboration in cloud environment.