Blockchain-Based Security Solutions for Big Data and IoT Applications

Abstract

For any distributed system, consensus plays a pivotal role in holding together the whole system. This is true not just for any blockchain (BC) peer-to-peer (P2P) Network but also for Cloud Computing where the Leader Election Problem is solved by the use of various consensus algorithms. No “one” consensus algorithm is universal or perfect. Depending upon the type of BC employed and the use case of the BC, there may be a consensus algorithm that would help the system reach optimum functioning without compromising the integrity of the system. While proof of work (PoW) [2] became the first Consensus Mechanism to be used in BC, there have been many consensus algorithms to date. These are mechanisms which help the P2P network of a BC arrive at a decision. The decision taken most often is who is going to add the next block on the BC. This decision is crucial because if there exists a malicious entity in the network who gets in charge of the chain, then it would be detrimental to the overall functioning of the network. The chapter discusses the following consensus algorithms-PoW [2], proof of stake, delegated proof of stake, Byzantine fault tolerance (BFT), Crash Fault Tolerance, Hashgraph Consensus Algorithm, Proof of Elapsed Time, and Proof of Authority (PoA). The pros of the consensus algorithms and main drawbacks against implementation such as low throughput and excessive consumption of bandwidth have been discussed as well. A comparative analysis of the aforementioned algorithms with a major focus on use cases has been done to help understand how such mechanisms may be used for designing solutions which surpass the initial application of cryptocurrency and delve into real-world solutions in the fields including but not limited to the Internet of Things (IoT) and big data.