# The Evolution and Optimization Strategies of a PBFT Consensus Algorithm for Consortium Blockchains
## 3 An Introduction to Mainstream Consensus Algorithms
### The Mainstream Consensus Algorithms of Public Blockchains
#### 3.1.1 Pow
(E-PoW) consensus mechanism to enhance the data security and improve the operational efficiency of patient monitoring. Similarly, [PERSON] et al. [28] validated PoW's practicality in peer-to-peer energy trading within residential communities, emphasizing its role in ensuring transaction integrity and secure payment mechanisms. Finally, [PERSON] et al. [29] combined PoW principles with edge computing through the Hedera consensus algorithm, incorporating permissionless access, scalability, and energy efficiency, suitable for multi-access edge computing (MEC) networks supporting the IoT. Overall, these studies highlight the evolution of PoW from a single-function consensus protocol to a flexible framework that adapts to energy constraints, security demands, and heterogeneous network environments. As shown in Table 3, the existing research on improvements to the PoW algorithm can be categorized into three systematic directions: resource allocation optimization, security enhancement, and functional utility expansion. In the area of resource allocation, improvements focus on dynamically adjusting computational power allocation strategies (such as multi-round verification mechanisms and edge computing collaboration) to reduce redundant computations, thereby significantly lowering energy consumption. The security enhancement direction is centered on addressing emerging threats, including the integration of quantum-resistant cryptography to defend against quantum attacks, as well as the development of parameter optimization mechanisms based on specific scenarios to improve data protection in particular fields (such as the healthcare IoT). Research on functional expansion seeks to move beyond the traditional goal of mining, exploring computational power reuse technologies (such as the integration of machine learning tasks) and layered ledger architectures. These research directions aim to enhance the practical value of PoW computing resources and achieve cross-domain collaboration and data synchronization. This trend shows that the PoW mechanism is evolving from an energy-intensive consensus to a configurable multi-objective framework by optimizing the verification logic, upgrading the cryptography technology, and improving the utilization of computing resources. This technological evolution not only alleviates the energy bottleneck of PoW but also enhances the flexibility of blockchain in heterogeneous networks and vertical application scenarios, and provides new ideas for optimizing the consensus mechanism in terms of security, sustainability, and value reuse. Although optimizations such as Green-PoW and Compute-and-Wait reduce redundant computations and energy consumption to some extent, they fail to fundamentally address the high energy costs and mining centralization inherent in PoW mechanisms. These improvements often require cross-domain technological integration and quantum-resistant designs, adding to implementation complexity while potentially undermining decentralization and posing long-term security risks.