Group Key Management with Multi-Level Security in the Internet of Things

Abstract

Data is constantly exchanged in networks of IoT devices. For the purpose of confidential- ity and integrity of the data, cryptographic keys are required to encrypt the exchanged data. The encryption process requires a reliable key management scheme to handle the creation and distribution of the group-key across the network devices. This thesis pro- poses an Adaptive Time-Bound Key Management Scheme for IoT. In which, the lifetime of the system is divided into equal periods of time-slots. Each time-slot has a unique key, which can be derived by the joining nodes using a few parameters sent by the key manager. In order for a node to join the network, it specifies the time-period or the number of time-slots it needs to join the network for. The server then responds with the values the node needs in order to generate the keys of the requested time-slots. This scheme ensures that the amount of seed values sent is based on the energy available at the receiving nodes. Our protocol is designed to suit a dynamic environment, with a high number of joins, predicted and unpredicted leaves while maintaining the security level required. Our key management scheme can adapt the amount of data sent by the server for the nodes based on the amount of energy that can be consumed in key generation by the client, while maintaining the required security level.