A Basic Theory of Lightweight Hierarchical Key Predistribution Scheme

Abstract

Key management is a basic requirement for any security solution. Lightweight key predistribution schemes (KPS) that establish symmetric secrets are best suited for resource constraint devices of low cost Internet of Things (IoT), sensors of Wireless Sensor Networks (WSN). Although there exist numerous elegant KPS, an appropriate hierarchical proposal is absent. To design such a scheme, we propose a combinatorial tool hierarchical set system/design. As an application of such a tool, we propose a deterministic lightweight hierarchical KPS (HKPS) that achieves the desirable design criteria:

• decentralized hierarchy of a fixed number of depths (l);

• resilient against compromise of (i) any number of lower level nodes; and (ii) a threshold number of nodes of same level in the hierarchy;

• non-interactive which saves bandwidth and energy;

• deterministic KPS which implies the nodes in the network have predictable behaviour of key rings;

• efficient as it uses hash chains rather than any public key based key exchange or bilinear maps;

• free to choose any basic KPS at any level/depth of hierarchy as per the requirement of that level;

• simplicity in design.

To enhance the resilience of the HKPS, we exploited the hash chain idea. Further, we instantiate the HKPS with a very efficient KPS Sensornet. The studies presented here are theoretical and does not contain any experimental and comparative results.