A Privacy-Preserving Authentication Scheme in an Edge-Fog Environment

In the three hierarchy architecture Edge-Fog-Cloud, delivering services with low latency is needed from the cloud to fog users with the intermediate of fog servers. Private and secure communication scheme will be necessary between fog users and dynamic fog servers. Fog servers are dynamic in joining and leaving the fog. This dynamic change of fogs must be transparent to the fog users. Our solution lies on the introduction of a mutual authentication between Fog users at the Edge of the network and the Fog servers at the Fog layer. We propose a fog user-fog server anonymous mutual authentication scheme in which fog user and fog server authenticate each other and establish a session key without disclosing user's real identity. Our scheme is based on Pseudonym Based Cryptography PBC, Elliptic Curve Discrete Logarithm Problem ECDLP and bilinear pairing to establish the session key. To evaluate the new solution, a security analysis and a formal validation with AVISPA are presented.