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%

Mixed public and secret-key cryptography for wireless sensor networks

Wireless sensor networks normally employ symmetric cryptography in their security systems. The most important issue in this area is the establishment of symmetric keys. In fact, even if many symmetric key management schemes have been proposed, none of them is optimal in every situation (e.g., in case of mobile nodes or no deployment knowledge or large networks). Furthermore, due to computational constraints of wireless sensor nodes, public-key cryptography is seldom used in wireless sensor networks. This paper investigates existing key management schemes and proposes a new key establishment routine that exploits both the benefits of public and symmetric encryption. The proposed routine exploits a symmetric transitory secret to authenticate nodes in the network, while actual pairwise keys are established using asymmetric cryptography