Design of an Efficient and Secure Authentication Scheme for Cloud-Fog-Device Framework Using Key Agreement and Management

IoT and Smart devices are typically deployed for real-time applications that need to communicate to the cloud infrastructure for data processing and storage. However, the cloud infrastructure has high network latency, and hence the fog has been introduced to form a layered cloud-fog-device framework. The layered architecture requires secure and efficient authentication between all the communicating entities. Secure authentication between fog nodes and cloud servers is not addressed in previous authentication schemes, which can result in severe threats like server masquerading and insider attacks. Ali et al. proposed an authentication key exchange scheme for the cloud-fog-device framework, which was found to be vulnerable to key revelation attacks and failed to provide user anonymity and session secrecy. To overcome the security issues identified, an improved authentication scheme based on key agreement and management was proposed. The scheme authenticates all the entities in the communication, including the cloud server. The scheme secures against privileged insider attacks, ensures user anonymity, untraceability, and session secrecy. The scheme was verified using rigorous cryptanalysis and its security was proved using the ROR model. Formal verification using scyther also confirmed its security against active and passive attacks. An efficiency analysis was performed by comparing the computation and communication costs with other relevant schemes. Functional analysis proved that the proposed scheme exhibits all the functionalities necessary for robust authentication in the cloud-fog-device framework. Overall, the new authentication scheme addresses the security concerns of the cloud-fog-device framework, making it a secure and reliable option for real-time applications.