Collaborative and verifiable key derivation protocol for smart home security: CV-KDP

Abstract

The ciphertext policy is a promising cryptographic technique for smart home data security, and the secrecy of the encryption key purely depends on the security of the key derivation mechanism. In a smart home network, many devices have limited computational and communication resources, and any such mechanism to create a security key should consider these computational and communicational constraints. In this paper, we propose a collaborative and verifiable key derivation protocol based on elliptic curve cryptography for smart home security. Our construction realizes a distributed computation of the security key without adding any extra energy consumption. The proposed collaborative mechanism effectively solves not only the key derivation mechanism security issue, but also adds a verifiability function to avoid keys falsification. Meanwhile, it helps markedly reduce the key derivation overhead at the energy constrained device. A comparison with other collaborative and non collaborative key derivation schemes, demonstrates that our scheme has somewhat better performance in terms of energy overhead at the constrained device side. Also, we provide proof of security of the proposed protocol.