A Survey on Consensus Protocols in Blockchain for IoT Networks (1809.05613v4)

Abstract: The success of blockchain as the underlying technology for cryptocurrencies has opened up possibilities for its use in other application domains as well. The main advantages of blockchain for its potential use in other domains are its inherent security mechanisms and immunity to different attacks. A blockchain relies on a consensus method for agreeing on any new data. Most of the consensus methods which are currently used for the blockchain of different cryptocurrencies require high computational power and thus are not apt for resource-constrained systems. In this article, we discuss and survey the various blockchain based consensus methods that are applicable to resource constrained IoT devices and networks. A typical IoT network consists of several devices which have limited computational and communications capabilities. Most often, these devices cannot perform intensive computations and are starved for bandwidth. Therefore, we discuss the possible measures that can be taken to reduce the computational power and convergence time for the underlying consensus methods. We also talk about some of the alternatives to the public blockchain like private blockchain and tangle, along with their potential adoption for IoT networks. Furthermore, we review the existing consensus methods that have been implemented and explore the possibility of utilizing them to realize a blockchain based IoT network. Some of the open research challenges are also put forward.

An Analysis of Blockchain-Based Consensus Protocols for IoT Networks

The paper, "A Survey on Consensus Protocols in Blockchain for IoT Networks," authored by Mehrdad Salimitari and Mainak Chatterjee, presents an in-depth examination of consensus mechanisms utilized in blockchain technology, particularly focusing on their applicability to resource-constrained Internet of Things (IoT) networks. This work meticulously explores the intersection between blockchain technology and IoT systems, emphasizing the potential benefits and challenges inherent in the integration of these two rapidly evolving fields.

Core Thesis

The integration of blockchain into IoT networks is motivated by blockchain's inherent security, privacy, and data integrity features. These attributes are crucial in IoT applications, where devices operate autonomously and require secure, decentralized data management without a central authority. However, the paper underscores that conventional blockchain implementations, primarily used in cryptocurrencies like Bitcoin, are not directly applicable to IoT environments due to the high computational and bandwidth demands of traditional consensus mechanisms, such as Proof of Work (PoW).

Examination of Consensus Protocols

The paper extensively details various consensus methods tailored for blockchain implementations, scrutinizing their practicality for IoT networks:

• Proof of Work (PoW): While effective for cryptocurrencies, PoW is computationally intensive and unsuitable for IoT devices with limited resources.
• Proof of Stake (PoS) and Variants: Including Delegated Proof of Stake (DPoS), Leased Proof of Stake (LPoS), and Proof of Importance (PoI), these methods reduce computational overhead but often depend on stake-based models, which do not naturally align with IoT settings.
• Byzantine Fault Tolerance (BFT) and Its Variants: Protocols like PBFT and dBFT offer lower latency and enhanced throughput, which are beneficial for IoT. However, BFT protocols typically incur high network overheads, limiting their scalability.
• Novel Methods: Algorithms such as Proof of Elapsed Time (PoET) and Tangle are highlighted for their potential in IoT networks due to their low computational demands and scalability. Tangle’s use of a Directed Acyclic Graph (DAG) structure to manage transactions is especially noted for its suitability to IoT constraints.

Implications for IoT Networks

The paper articulately discusses that for blockchain to be effectively implemented in IoT networks, the chosen consensus method must balance security, privacy, resource efficiency, and scalability. IoT devices, with their resource constraints, necessitate consensus protocols that minimize computational and storage requirements while maximizing throughput and minimizing latency. Incorporating blockchain in IoT can pave the way for secure data sharing, enhanced privacy, and automated decision-making processes devoid of centralized control.

Forward-looking Speculations

The research posits that further advances are necessary in several areas to enable feasible blockchain applications in IoT:

1. Development of Lightweight Consensus Protocols: Future research should focus on creating consensus mechanisms that can operate efficiently on low-power devices without compromising security.
2. Scalability Solutions: Blockchain frameworks need to evolve to handle the vast number of devices and data generated in IoT networks effectively.
3. Interdisciplinary Approaches: Bridging insights from computer science, cryptography, and wireless communications will be crucial to developing a robust blockchain infrastructure for IoT.

Conclusion

Overall, the authors provide a comprehensive survey of consensus mechanisms in blockchain and their potential adaptation for IoT networks. The paper serves as an invaluable resource for researchers aiming to delve into the intricate dynamics of blockchain and IoT, presenting both the challenges and the innovative strategies that could guide future development in this inter-disciplinary domain. Future work in this area is likely to yield significant advancements as blockchain technology continues to mature and as the IoT landscape expands, presenting novel opportunities and challenges alike.