Enhanced Blockchain Based Key Management Scheme against Key Exposure Attack

The data collected by IoT devices is of great value, which makes people urgently need a secure device key management strategy to protect their data. Existing works introduce the blockchain technology to transfer the responsibility of key management from the trusted center in the traditional key management strategy to the devices, thus eliminating the trust crisis caused by excessive dependence on third parties. However, the lightweight implementation of IoT devices limits the ability to resist side channel attacks, causing the private key to be exposed and subject to masquerading attacks. Accordingly, we strengthen the original blockchain based key management scheme to defend against key exposure attack. On the one hand, we introduce two hash functions to bind transactions in the blockchain to legitimate users. On the other hand, we design a secure key exchange protocol for identifying and exchanging access keys between legitimate users. Security analysis and performance show that the proposed scheme improves the robustness of the network with small storage and communication overhead increments.