Abstract
Accretion of Internet of Things (IoT) devices connected to the cloud has created several performance issues such as high latency and network congestion. To overcome these issues, fog computing has been deployed at the edge of the network between the cloud and the user network. Although fog comes with promising solutions to overcome the performance issues in the cloud, security and privacy issues need further attention. Designing security protocols in resource-limited user devices (i.e. IoT) is a challenging task. We propose a lightweight hierarchical key management with a deterministic scheme that guarantees a shared key between a fog node and a user device. Furthermore, it is a scalable scheme in which a new node can be easily added without affecting the security of the network. Moreover, the security can be enhanced without increasing the storage requirements of user devices.