Proof of Policy (PoP): A New Attribute-Based Blockchain Consensus Protocol

Blockchain technology is transforming industries like finance, supply chain, governance, and healthcare. This paper analyzes blockchain architecture, applications, challenges, and performance. Key attributes—decentralization, immutability, transparency, and security—enable secure peer-to-peer transactions without intermediaries. Consensus mechanisms such as Proof of Work (PoW) and Proof of Stake (PoS) are examined for their trade-offs in scalability, energy efficiency, and security. In healthcare, blockchain addresses security and interoperability issues in centralized Personal Health Record (PHR) systems. Solutions using Ethereum, Hyperledger, smart contracts, and IPFS enhance Electronic Health Record (EHR) management by improving data integrity, privacy, and access control while reducing costs. A containerized microservices architecture further enhances scalability. Blockchain performance, evaluated using the BLOCKBENCH framework, highlights gaps in transaction throughput compared to traditional databases. Despite scalability, interoperability, and regulatory challenges, ongoing research focuses on optimizing consensus mechanisms, integrating database principles, and improving healthcare interoperability, advancing blockchain’s real-world applications

Blockchain technology is a decentralized and secure paradigm for data processing, sharing, and storing. It relies on consensus protocol for all decisions, which focuses on computational and resource capability. For example, proof of work (PoW) and proof of stake (PoS) are the most famous consensus protocols that are currently used. However, these current consensus protocols are required to recruit a node with a high computational or a large amount of cryptocurrency to act as a miner node and to generate a new block. Unfortunately, these PoW and PoS protocols could be impractical for adoption in today’s technological fields, such as the Internet of Things and healthcare. In addition, these protocols are susceptible to flexibility, security, and fairness issues, as they are discussed in detail in this work. Therefore, this paper introduces a proof of fairness (PoF) as a dynamic and secure consensus protocol for enhancing the mining selection process. The selection of the miner node is influenced by numerous factors, including the time required to generate a block based on the transaction’s sensitivity. Firstly, a reverse auction mechanism is designed as an incentive mechanism to encourage all nodes to participate in the miner selection process. In a reverse auction, each node will draw its strategy based on its computational capability and claimed cost. Secondly, an expressive language is developed to categorize transaction types based on their sensitivity to processing time, ensuring compatibility with our miner selection process. Thirdly, a homomorphic concept is designed as a security and privacy scheme to protect the bidder’s data confidentiality. Finally, an extensive evaluation involving numerical analysis was carried out to assess the efficiency of the suggested PoF protocol, which confirms that the proposed PoF is dynamic and more efficient than current PoW and PoS consensus protocols.

The article investigates the process of block formation in blockchain networks and the impact of node network architecture and consensus algorithms on their scalability and performance. Analysis of blockchain system scalability is important due to problems that arise when network load increases, particularly the increase in the number of block forks and transaction confirmation times. The research focuses on studying the impact of network delays and the choice of consensus algorithm on the performance and scalability of blockchain networks. The main attention is devoted to mathematical models that describe block formation, as well as the analysis of factors affecting transaction processing speed and throughput. The primary consensus algorithms, such as Proof of Work (PoW) and Proof of Stake (PoS), are considered, and their impact on scalability in implementations based on the Ethereum Virtual Machine (EVM) and Bitcoin is compared. Experimental studies using Geth and Amazon cloud services revealed that the application of the Proof of Stake (PoS) consensus algorithm increases network performance by reducing the complexity of the block formation process in blockchain networks by 99% and accelerates consensus achievement by 70% compared to Proof of Work (PoW). It was also established that increasing the number of nodes from 5 to 50 reduces the network's throughput by almost 10%, and the average confirmation time doubles. The obtained results are aimed at solving the scalability issue by reducing transaction confirmation times for the implementation of decentralized technologies in the Internet of Things (IoT) sphere, where processing speed and storage of large volumes of data are critically important. Keywords: blockchain, block formation, consensus algorithms, decentralized technologies, Ethereum Virtual Machine (EVM), Internet of Things (IoT), mathematical modeling, network delays, scalability.

This research document demonstrates the understanding of two key elements: Proof of Work (PoW) and Proof of Stake (PoS) within cryptocurrency. Cryptocurrency is often misunderstood as just volatile and risky but many investors do not understand what it even is. What is proof of work (BTC)? What is proof of stake (ETH)? How are they similar and how are they different? Cryptocurrency is actually more relatable that originally imagined once a person understands digital currency, money, it’s origins, and how they hold similar monetary value within their own wallets. Cryptocurrency in PoW involves complicated mathematical equation solving via mining from a large growing pool of miners. These miners receive rewards such as bitcoin/tokens/etc. from their mined hash blocks verified, and blocks added to the blockchain. Challenges are that there are many miners and there may be a computational limit per core of each PC to be able to mine since Bitcoin has increased its difficulty 70 billion times since it started. BTC or Bitcoin is still widely trusted due to its increasing difficulty to race to the finish line to finish the advanced math computations. Whereas within PoS this is not a race between the masses and advanced math computations, but a validator that generally has more put in their stake vs. gained by receiving the processing fees associated. ETH or Ethereum has shifted from PoW to PoS for its better energy efficiency in resources. It has employed many other additional checks from Casper to Gasper which is the combination of Casper (fork-choice algorithm), LMD-GHOST (heavest observed subtree), and finality which requires 2/3rd agreement as well as once a block is justified it is upgraded to a finalized block. the similarities between the two PoW and PoS are that they are consensus-driven algorithms. They are designed to reach an agreement between the systems in place before each block is placed in the blockchain. Additionally, they also have a shared public ledger that operates on a global if not international scale. With blockchains, there is always only one true version and this is relying on a network rather than a governing authority like a bank/government entity to provide security and to prevent fraudulent transactions. It is still widely contested which is better than these two well-known consensus algorithms and it is still widely contested. The best answer is suited on a per investor per business basis in terms of the willingness of taking a risk just like any investment. This document serves to help provide guidance in the understanding of cryptocurrency of two main consensus algorithms, its similarities, differences, and help identify see what a potential investor the reader may be.

The accelerating pace of adoption of decentralized applications requires the use of efficient, high-performance blockchain infrastructures. These blockchains are supported by consensus algorithms that are critical determinants of scalability, transaction speed, costs, and security. Developers are still unaware of the most useful options because there is a large gap in information regarding the comprehensive evaluation of these algorithms in practice. This study aims to test and compare the performance of the three most popularly used blockchain consensus protocols - Proof of Work (PoW), Proof of Stake (PoS) and Delegated Proof of Stake (DPoS) with the aim to improve the application of decentralized systems. By deploying smart contracts on real blockchain test networks (Callisto for PoW, Sepolia for PoS, and Tron Nile for DPoS), the research explores key performance metrics such as block time, deploy gas fee, block gas limit, and block size. The experiments utilize tools like Remix IDE and Tron-IDE, highlighting the practical implications of consensus algorithms under varying real-world conditions, including network congestion and transaction volatility. Tron Nile excels in speed and capacity but incurs high gas fees, Sepolia balances performance with moderate costs, and Callisto emphasizes cost efficiency at the expense of speed and scalability. Insights derived from this study provide valuable guidelines for developers to choose suitable consensus mechanisms based on the specific requirements of decentralized applications

Cryptocurrencies have seen a massive surge in popularity and behind these new virtual currencies is an innovative technology called the blockchain: a distributed digital ledger in which cryptocurrency transactions are recorded after having been verified. The transactions within a ledger are verified by multiple clients or “validators,” within the cryptocurrency's peer-to-peer network using one of many varied consensus algorithms for resolving the problem of reliability in a network involving multiple unreliable nodes. The most widely used consensus algorithms are the Proof of Work (PoW) algorithm and the Proof of Stake (PoS) algorithm; however, there are also other consensus algorithms which utilize alternative implementations of PoW and PoS, as well as other hybrid implementations and some altogether new consensus strategies. In this paper, we perform a comparative analysis of typical consensus algorithms and some of their contemporaries that are currently in use in modern blockchains. Our analysis focuses on the algorithmic steps taken by each consensus algorithm, the scalability of the algorithm, the method the algorithm rewards validators for their time spent verifying blocks, and the security risks present within the algorithm. Finally, we present our conclusion and some possible future trends for consensus algorithms used in blockchains.

In the white book of Bitcion, Satoshi Nakamoto described a bitcoin system that can realize point-to-point online payment without a third-party organization. After supporting this magical application scenario and subverting the traditional centralized system, the blockchain technology has attracted worldwide attention, triggered a research upsurge of blockchain consensus algorithm, and produced a large number of innovative applications. Although various consensus algorithms continue to evolve with the iteration of blockchain products and applications, Proof of Work (POW) and Proof of Skake (POS) algorithms are still the core of consensus algorithms. This paper discussestwo algorithms of POW and POS in blockchain consensus mechanism, and analyzes the advantages and the existing problems of the two consensus mechanisms. Since consensus mechanism is the main focus of blockchain technology and has many influencing factors, this paper discusses the current problems and some improved ideas, and selectes some typical algorithms for a more systematic introduction. In addition, some important issues related to safety and performance are also discussed. This paper provides the researchers a great reference on blockchain consensus mechanism.

Electronic Health Records (EHR) is the electronic form of storing a patient's medical history. EHR contains patient’s data such as progress notes, medications, prescriptions, vital signs, scan reports and laboratory data. Transferring EHR over the internet improves the quality of health care and reduces medical costs. However, in the traditional system, the EHR are stored across different decentralised hospitals, making data sharing difficult and increasing the risk of patient privacy. A privacy-preserving framework for electronic health records using blockchain technology is implemented to address these issues. The patient has complete control over the EHR, and the patient can share their health records with doctors of various medical institutions. The privacy and security of the patient’s EHR are guaranteed by the verifiability and immutability property of the blockchain technology. The doctor upload the EHR, and it is encrypted using the SHA256 hashing algorithm and stored as a separate block. The patient shares the EHR with the doctor of any medical institution through the unique key shared via the doctor’s email. The doctor can access and update the EHR using the shared key. The block validation is done using Delegated Proof of Stake (DPoS) consensus algorithm, which guarantees the privacy of the patient’s data. The proposed system based on the DPoS algorithm has considerabe reduction in resource utilisation, computational capacity, time, and cost for EHR transactions.

The Internet of Things (IoT) is converting today's physical world into a complex and sophisticated network of connected devices on an enormous scale. The existing malicious node detection mechanism in traditional approaches lacks in transparency, availability, or traceability of the detection phase. To overcome these concerns, we provide a decentralized technique using blockchain technology. Despite the fact that blockchain technology is applicable to create that type of models, existing harmony set of instructions are susceptible to do violence to such as DoS and Sybil, making blockchain systems unfeasible. Here, a new Proof-of-Improved-Participation (PoIP) harmony instruction was suggested that benefits the participation rules to select honest peers for mining while limiting malicious peers. Under an evaluation the PoIP outperforms the Proof-of-Work (PoW) instructions are demonstrated, Proof of Stake (PoS) instructions in terms of energy consumption, accuracy, and bandwidth. To compare the three consensus protocols with respect to efficiency, we build a lightweight mining model and find that PoIP consensus has greater efficiency than PoW and PoS. PoIP has 25% lower attack risk than existing consensus. As a consequence, our suggested methodology can provide the needed security with minimal attack risk and high accuracy, according to the analysis results. As a result, suggested consensus is more efficient than existing methods in terms of block generation time. Hence we suggest that suggested consensus is very suitable for IoT-based applications especially in healthcare.

The arrival of the Proof of Stake (POS) consensus algorithm has solved the problem of energy waste caused by Proof of Work (POW) through replacing POW’s wasteful computing power with proof of possession of a certain amount of locked token called “Stake”. The weight of the latter will allow its holder to be more likely to be selected as “Leader” and earn a corresponding reward. However, the mechanism adopted by POW, the POS (and its derivatives) promotes the mining monopoly by the most powerful or the wealthiest members of the network without any other tangible criterion proving that these participants actively contribute to the security of the Blockchain network and respect the security recommendations (application of urgent updates for example) issued by the development team of said Blockchain.In this paper, we propose a new consensus algorithm called “Proof of Conformity -PoC-” favoring the node security aspect and offering additional reliability to the Blockchain. Proof of Conformity improvement involves the introduction of a new impact factor in the node weight calculation named “Node Security Metric” (NSM).NSM is primarily based on the Common Vulnerability Scoring System (CVSS). Furthermore, NSM computation mainly relies on the re-calculation of the weight of each network node based on the stability and security of their software and hardware environment. Our new approach will strengthen the node security index and encourage miners with up-to-date environments. Moreover, compliant, proactive and vigilant nodes will increase their chances of being selected as “Leader” and earning rewards.PoC is theoretically evaluated through simulation scenarios and the result obtained shows that our approach ensures that participating nodes deemed secure are more likely to be designated as “Leader” based on their conformity rates reflected by their NSM score.KeywordsBlockchainConsensus algorithmCVSSDistributed systemSecurityProtocolsDecentralised system

Consensus algorithms are essential for achieving agreement among nodes in blockchain systems. However, traditional consensus algorithms such as Proof of Work (PoW) and Proof of Stake (PoS) can be resource-intensive and unsuitable for lightweight private blockchain applications. This paper proposes using the RSA (Rivest–Shamir–Adleman) encryption algorithm as a consensus algorithm for a lightweight private blockchain in the context of a college placement system. RSA offers several advantages over traditional consensus algorithms, including simplicity, efficiency, and security. Moreover, RSA can be implemented on resource-constrained nodes, making it a promising solution for lightweight blockchain applications. The resource constrained nodes are students, academic department, training and placement cell department, and placement cell coordinator. The company acts as a client. The movement of the student’s data to companies is recorded as transactions on the distributed ledger or blockchain, allowing the student to track its progress.

Blockchain technologies have gained significant popularity for their decentralized and tamper-evident characteristics. The key component of these technologies is the consensus protocol that dictates the correctness and operational efficiency of the system. Bitcoin’s Proof of Work(PoW) is one such widely used promising consensus protocol. The major concern of the PoW consensus is the harm it does to the environment. It consumes a large amount of electricity and produces a high carbon footprint on the environment. In this paper, we propose "Proof-of-Pedal(PoP)", a novel Byzantine consensus protocol to address these major environmental issues in PoW. The proposed PoP consensus protocol is designed to replace the computer energy in PoW with human energy, specifically calories generated through cycling. It has been implemented on Pedalchain(also referred to as Greenchain), a novel blockchain system and support for both public and permissioned environments. The PoP consensus protocol represents a variation of Proof-of-Stake (PoS), employing PedalCoin cryptocurrency tokens as the staking mechanism for block miners. The protocol facilitates applications that allocate Pedalcoins to individuals as rewards for their cycling activities and the subsequent reduction in carbon emissions achieved through those activities. In the Pedalchain blockchain, individual activities and corresponding carbon footprint scores are securely recorded as transactions, resulting in automatic credit of Pedalcoins to the respective individuals. To ensure privacy while capturing Cycling activity and carbon footprint data, we have developed ClimGuards, a mobile application enabled with Self-Sovereign Identity (SSI) technology. The system also incorporates a feature that allows users to spend their Pedalcoins at a variety of businesses, including sports stores, hotels, restaurants, and more, while unlocking special offers. Moreover, the scalability of the system enables its potential extension to diverse applications. Through this approach, our aim is to incentivize cycling using an innovative cryptocurrency application and contribute to the promotion of a healthier nation.

Diverse technologies, such as machine learning and big data, have been driving the prosperity of the Internet of Things (IoT) and the ubiquitous proliferation of IoT devices. Consequently, it is natural that IoT becomes the driving force to meet the increasing demand for frictionless transactions. To secure transactions in IoT, blockchain is widely deployed since it can remove the necessity of a trusted central authority. However, the mainstream blockchain-based IoT payment platforms, dominated by Proof-of-Work (PoW) and Proof-of-Stake (PoS) consensus algorithms, face several major security and scalability challenges that result in system failures and financial loss. Among the three leading attacks in this scenario, double-spend attacks and long-range attacks threaten the tokens of blockchain users, while eclipse attacks target Denial of Service. To defeat these attacks, a novel bidirectional-linked blockchain (BLB) using chameleon hash functions is proposed, where bidirectional pointers are constructed between blocks. Furthermore, a new committee members auction (CMA) consensus algorithm is designed to improve the security and attack resistance of BLB while guaranteeing high scalability. In CMA, distributed blockchain nodes elect committee members through a verifiable random function. The smart contract uses Shamir's secret-sharing scheme to distribute the trapdoor keys to committee members. To better investigate BLB's resistance against double-spend attacks, an improved Nakamoto's attack analysis is presented. In addition, a modified entropy metric is devised to measure eclipse attack resistance across different consensus algorithms. Extensive evaluation results show the superior resistance against attacks and demonstrate high scalability of BLB compared with current leading paradigms based on PoS and PoW.

Cryptocurrency mining, especially Bitcoin's Proof of Work (PoW), significantly impacts the environment through high energy consumption, carbon footprint, and e-waste. Ethereum's adoption of Proof of Stake (PoS) in 2022 offers a potential solution to reduce these effects. This study compares the environmental impacts of PoW and PoS, focusing on energy consumption, mining efficiency, hash rate, and carbon footprint. Using regression analysis and t-tests on data from Bitcoin (PoW) and Ethereum (before and after PoS) from 2017 to 2024, the results show that PoS significantly reduces energy consumption, carbon footprint, and e-waste, while improving mining efficiency. The findings highlight that transitioning to PoS can mitigate the environmental impact of cryptocurrency mining and encourage its broader adoption to align with global sustainability goals.

DT-DPoS: A Delegated Proof of Stake Consensus Algorithm with Dynamic Trust