Performance and Security Assessment of a PKC Based Key Management Scheme for Hierarchical Sensor Networks

Security and efficiency are the two conflicting requirements for all key management schemes operating in the sensor environment. Symmetric key cryptography based schemes adequately use available resources but secure key distribution is a major problem. Public key cryptography based schemes require enormous resource consumption for making the system effectively secure. This work focuses on presenting public key cryptography based key management scheme as an efficient as well as a secure solution for sensors. A cluster based architecture is used where the base station serves as the key distribution center maintaining public keys for all the nodes in the network. The private keys are to be pre-deployed in all nodes whereas the remaining public key exchanges are achieved via minimal broadcasts. Elliptic curve cryptography is the algorithm used which is light on node resources. Each node stores a minimal number of keys while encryption/decryption operations are also ensured to be cost effective. The approach shows that public key cryptography can match up to the efficiency of symmetric key schemes while providing betterment in security at the same time.