Protocol | Hierarchy | Distribution | Number of | Group | Regeneration |
---|---|---|---|---|---|
 | keys per sensor | mechanism | keys | communication | of the keys |
Pairwise keys | Static predeployed | One key with every sensor | Many tunnels per group | No | |
Secured paths through trusted sensors | Static predeployed | One ring pool of keys (selected randomly) | Many tunnels per group | No | |
LKHW [12] | Tree-based key management | Static predeployed | One key with the superior node in the tree | Many tunnels per group | No |
PIKE [13] | Secured paths through trusted sensors | Static predeployed | One ring pool of keys (equal to the number of needed trusted nodes) | Many tunnels per group | No |
RDKM [16] | Tree-based key management | Computed through exchanges | One key for initial exchanges, pairwise keys, and one cluster key in each sensor | Many tunnels per group | On demand (one sensor departure or attack on a secure channel) |
Many kinds of keys (pairwise and group) | Static or computed on predeployed | One key for group communication + one key with every sensor | One tunnel per group | No | |
The proposed protocol DynTunKey | One group key | Computed on exchanges | One key for initial exchanges and one group key in each sensor | One tunnel per group | Periodic |