Key Related Work Reference Network Security Model Limitations Arc hitecture LIGER Flat hws Hybrid key management scheme .Large numbers of (LIGER) keys stored and key .Unbalanced key distribution exchanges LION-standalone key mgmt Increased node .TIGER-KDC based key mgmt compromise with increased key storas Kejie lu Flat hWsn 2 key management schemes Large numbers of Random key pool-based pre keys stored and key distribution exchanges Polynomial-based pre-distribution enei Du-Scheme Hierarchical Key management scheme .Location dependent egion-based .C-neighbor concept network architecture HWSN ECC supports exchange of symmetric No energy analysis for secure routingKey Related Work 6 Reference Network Architecture Security Model Limitations LIGER Flat HWSN Hybrid key management scheme (LIGER) •Unbalanced key distribution •LION-standalone key mgmt. •TIGER-KDC based key mgmt. •Large numbers of keys stored and key exchanges •Increased node compromise with increased key storage Kejie Lu Flat HWSN 2 key management schemes •Random key pool-based pre￾distribution •Polynomial-based pre-distribution •Large numbers of keys strored and key exchanges •No analysis for energy usage Du-Scheme Hierarchical Region-based HWSN Key management scheme •C-neighbor concept •ECC supports exchange of symmetric key •Location dependent network architecture •No energy analysis for secure routing