In recent years, Blockchain technology has been used in many fields, including Machine Learning, Cloud Computing, and the Internet of Things (IoT). Integrating Blockchain and IoT with its lightweight devices has benefits such as enhanced security and reduced costs. In this field, critical challenges that need to be addressed are providing security and performance guarantees. An available solution to meet the mentioned challenges is TrustChain. Unlike conventional Blockchains, TrustChain does not have a single global chain. Instead, each node is responsible for building and maintaining its own local chain. With all the benefits, TrustChain is vulnerable to the Whitewashing attack. Moreover, once a fatal error occurs, the recovery time of each TrustChain node is considerably high. In this paper, we propose a solution to address the above-mentioned attack by the implementation of a smart contract-based authentication system on top of TrustChain. Moreover, we connected the TrustChain to a distributed cloud (i.e., IPFS), with the aim of significantly reducing the recovery time of nodes (up to 90%) in the fatal errors. Finally, we evaluate improved TrustChain with PoW Blockchains simulator (As the most secure and basic Blockchain) from two aspects of security and performance for lightweight devices and prove that the improved TrustChain propagation delay is less than a PoW Blockchain and it is more secure than PoW systems against main attacks.

Keywords