Transitory Master Key Transport Layer Security for WSNs

Security approaches in Wireless Sensor Networks (WSNs) are normally based on symmetric cryptography. Instead of symmetric encryption, some alternative approaches have been developed by using public-key cryptography. However, the higher computational cost represents a hard limitation to their use. In this paper, a new key management protocol is proposed. A transitory symmetric key is used to authenticate nodes in the network during the key establishment. However, pairwise keys are established using asymmetric cryptography. A theoretical analysis shows that the computational effort required by the public key cryptosystem is greatly reduced, while the security of the network is increased with respect to state-of-the-art schemes based on a transitory master key. Moreover, an experimental analysis demonstrates that this proposed approach can reduce the time spent for key establishment by about 35%.