Proposed Authentication Protocol for IoT using Blockchain and Fog Nodes

The IoT offers enormous opportunities and also brings some challenges. Authentication considered one of the main challenges introduced by IoT. IoT devices are not able to protect themselves due to there limited processing and storage capabilities. Researchers proposed authentication algorithms with either a lack of scalability or vulnerable to cyberattacks. In this paper, we propose a decentralized token-based authentication based on fog computing and blockchain. The protocol provides a secure authentication protocol using access token, ECC cryptog-raphy, and also blockchain as decentralized identity storage. The blockchain uses cryptographic identifiers, records immutability, and provenance, which allows the implementation of a decentral-ized authentication protocol. These features ensure a light and secure identity management system. We evaluate this protocol communication between controller, gateways, and devices using AVISPA/ HLPSL, and results obtained from AVISPA simulation shows that our protocol is safe based on secrecy and strong authentication criteria. The paper uses four test cases to test the Ethereum smart contract implementation to ensure the system functions properly.