Homomorphic Multicast Group Key Management : Using Routing Protocol for Low Power and Lossy Networks
Dashmeet Kaur Ajmani, Apoorv Srivastava, Joel D'souza, Jibi Abraham · 2020
Group key management for any secure multicast architecture is an essential functional building block which is a security measure just as important as encryption and authentication. Broadly speaking, two main functional entities manage the security of a multicast session: a Group Controller (GS) responsible for authorization, authentication, and access control, and a Key Server (KS) responsible for maintaining and distributing the required key material. Whenever a service provider sends a multicast content, it is encrypted using a Traffic Encryption Key (TEK) that legitimate members can decrypt on delivery of multicast content. To prevent a leaving or an expelled member from the group from continuing to decrypt the secret multicast messages, the KS generates a new TEK and securely distributes it to the remaining members of the group except the one left. Due to the inherent resource limitation of Internet of Things (IoT) devices, these security protocols cannot be extended as is for IoT devices and sensor nodes. How to securely generate and distribute the new TEK without disruption of service and degradation of network performance remains a major challenge. This work aims at providing a solution in group key management for IoT devices to the aforementioned gap. The proposal is to manage keys for multiple nodes belonging to multiple groups using Routing Protocol for Low Power and Lossy Networks (RPL) to build topology and add to it the ability of Multigroup Key Management using Key Store and Homomorphic encryption. Our solution is using Paillier Encryption scheme to produce keys. These keys are stored in the Keystore. These keys would be distributed to the root controller nodes, which are RPL DODAG roots, and these root nodes will distribute it to their respective nodes in a group. The cases of members leaving groups and joining groups also has been handled.