Improving the Key Exchange Process of the eXtended Triple Diffie-Hellman Protocol with Blockchain

The demand for safeguarding communications between people and equipment has been driven by recent breakthroughs in miniature smart data gathering devices. Traditional techniques based on key exchange protocols cannot be implemented by resource-constrained embedded devices, therefore the BlockChain-Based X3DH (BCB-X3DH) protocol, which is based on a resilient decentralization of the eXtended Triple Diffie-Hellman (X3DH) protocol, has been developed. This work extends the analysis to fit a generic Smart City scenario with Edge and IoT nodes, using intensive analysis on Raspberry Pi 3 model B+ and Raspberry Pi 4 to verify that the new protocol is not only resistant to well-known distributed attacks, but can also be executed by miniaturized hardware, saving resources, energy, and battery life.