A security and performance analysis of proof-based consensus protocols

Blockchain is a disruptive technology that will revolutionize the Internet and our way of living, working, and trading. However, the consensus protocols of most blockchain-based public systems show vulnerabilities and performance limitations that hinder the mass adoption of blockchain. This paper presents and compares the main proof-based consensus protocols, focusing on the security and performance of each consensus protocol. Proof-based protocols use the probabilistic consensus model and are more suitable for public environments with many participants, such as the Internet of Things (IoT). We highlight the centralization tendency and the main vulnerabilities of Proof of Work (PoW), Proof of Stake (PoS), and their countermeasures. We also analyze and compare alternative proof-based protocols, such as Proof of Elapsed Time (PoET), Proof of Burn (PoB), Proof of Authority (PoA), and Delegated Proof of Stake (DPoS). Finally, we analyze the security of the IOTA consensus protocol, a DAG-based platform suited for the IoT environment.