Bidirectional hash chains generically enhances resilience of key predistribution schemes

Key predistribution is an adequate technique to solve the (symmetric) key management problem in distributed systems. Owing to the large network size $\left({\cal N} \right)$N and limited memory (z) in devices, a given key is shared by a number of nodes (r). This leads to a generic degradation of a network's resilience. Several works dedicate to reduce this deterioration by applications of lightweight mechanisms. Few such prominent approaches are the q-composite method by Chan et al., hashed random preloaded subset by Ramkumar et al. and one-way function iterates by Cichoń et al. or its special case of hash chains (HCs) by Bechkit et al. The authors introduce the generic concepts of bidirectional HCs (2HCs) and q-composite 2HCs. A thorough qualitative investigations of vital system parameters indicate trade-offs between significant improvement in a network's resilience and nominal increment in space and computational overheads in constituent devices. In the process, they correct an error in resilience computations in the works of Bechkit et al. Instantiations of their indigenous concepts to three prominent schemes that represent individual types of key predistribution schemes (one random and two deterministic) concretely quantify their analyses.