To achieve security in WSN it is important to be able to perform various cryptographic operations, including encryption, authentication and authorization. Keys for these cryptographic operations must be setup by communicating nodes before they can exchange information securely. Key management schemes are mechanisms which are used to establish and distribute various kinds of cryptographic keys in the network, such as individual keys, pairwise keys and group keys. Key management is essential cryptographic primitive upon which other security primitives are built. Most security requirements such...