In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no...In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no technical analysis and comparison as a guideline to determine which type of consensus mechanism should be adopted in a specific scenario/application.To this end,this work investigates three mainstream consensus mechanisms in the blockchain,namely,Proof of Work(PoW),Proof of Stake(PoS),and Direct Acyclic Graph(DAG),and identifies their performances in terms of the average time to generate a new block,the confirmation delay,the Transaction Per Second(TPS)and the confirmation failure probability.The results show that the consensus process is affected by both network resource(computation power/coin age,buffer size)and network load conditions.In addition,it shows that PoW and PoS are more sensitive to the change of network resource while DAG is more sensitive to network load conditions.展开更多
This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is t...This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is to comprehensively investigate prominent mechanisms’security features and vulnerabilities,emphasizing their security considerations,applications,challenges,and future directions.The existing literature offers valuable insights into various consensus mechanisms’strengths,limitations,and security vulnerabilities and their real-world applications.However,there remains a gap in synthesizing and analyzing this knowledge systematically.Addressing this gap would facilitate a structured approach to understanding consensus mechanisms’security and vulnerabilities comprehensively.The study adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and computer science standards and reviewed 3749 research papers from 2016 to 2024,excluding grey literature,resulting in 290 articles for descriptive analysis.The research highlights an increased focus on blockchain consensus security,energy efficiency,and hybrid mechanisms within 60%of research papers post-2019,identifying gaps in scalability,privacy,and interoperability for future exploration.By synthesizing the existing research and identifying the key trends,this SLR contributes to advancing the understanding of blockchain consensus mechanisms’security and guiding future research and structured innovation in blockchain systems and applications.展开更多
In this paper,we provide a new theoretical framework of pyramid Markov processes to solve some open and fundamental problems of blockchain selfish mining under a rigorous mathematical setting.We first describe a more ...In this paper,we provide a new theoretical framework of pyramid Markov processes to solve some open and fundamental problems of blockchain selfish mining under a rigorous mathematical setting.We first describe a more general model of blockchain selfish mining with both a two-block leading competitive criterion and a new economic incentive mechanism.Then we establish a pyramid Markov process and show that it is irreducible and positive recurrent,and its stationary probability vector is matrix-geometric with an explicitly representable rate matrix.Also,we use the stationary probability vector to study the influence of orphan blocks on the waste of computing resource.Next,we set up a pyramid Markov reward process to investigate the long-run average mining profits of the honest and dishonest mining pools,respectively.As a by-product,we build one-dimensional Markov reward processes and provide some new interesting interpretation on the Markov chain and the revenue analysis reported in the seminal work by Eyal and Sirer(2014).Note that the pyramid Markov(reward)processes can open up a new avenue in the study of blockchain selfish mining.Thus we hope that the methodology and results developed in this paper shed light on the blockchain selfish mining such that a series of promising research can be developed potentially.展开更多
The energy use of Bitcoin is fiercely debated among academics,practitioners,and the general public.This debate is often biased and characterized by a lack of understanding.Therefore,I start this paper with a discussio...The energy use of Bitcoin is fiercely debated among academics,practitioners,and the general public.This debate is often biased and characterized by a lack of understanding.Therefore,I start this paper with a discussion of the fundamentals of Bitcoin,which includes the clarification of widely held misconceptions.Next,I illustrate how Bitcoin is related to energy and describe the underlying incentive mechanism.In the main body of the paper,I discuss various components of Bitcoin’s energy use,including the amount,composition,and geographical distribution of the energy,as well as emerging positive and negative effects.These components are then combined into a comprehensive framework that provides a solid foundation for future academic research and presents practitioners with the big picture of how and why Bitcoin requires energy and whether this can be justified from an environmental point of view.展开更多
PoW(Proof of Work)plays a significant role in most blockchain systems to grant an accounting right over decentralized participants and ensure tamper resistance.Though hash functions are generally exploited for PoW due...PoW(Proof of Work)plays a significant role in most blockchain systems to grant an accounting right over decentralized participants and ensure tamper resistance.Though hash functions are generally exploited for PoW due to their merits on summering,anti-collision,and irreversibility,they cannot certify that the bookkeeper is exactly the worker.Thereafter,such insistence may lead to abuse or even embezzlement of computing power for the benefit of malicious miners.To preserve the functionality of PoW but also bind the miners’signing keys with their works,we build a post-quantum PoW scheme by changing the approximate closest vector norm for probabilistic NTRUSign.Different from the schemes based on hash functions,our scheme takes signing as the proof of work where signature verification is just the evidence of block reward.We also presented a method to adjust the difficulty of signing by modifying the probability of generating a correct signature.The performance of our scheme is also analyzed theoretically and experimentally,which implies its practicability and advantages.展开更多
Blockchain technology has gained widespread adoption in recent years due to its ability to enable secure and trans-parent record-keeping and data transfer.A critical aspect of blockchain technology is the use of conse...Blockchain technology has gained widespread adoption in recent years due to its ability to enable secure and trans-parent record-keeping and data transfer.A critical aspect of blockchain technology is the use of consensus algorithms,which allow distributed nodes in the network to agree on the state of the blockchain.In this review paper,we exam-ine various consensus algorithms that are used in blockchain systems,including proof-of-work,proof-of-stake,and hybrid approaches.We go over the trade-offs and factors to think about when choosing a consensus algorithm,such as energy efficiency,decentralization,and security.We also look at the strengths and weaknesses of each algorithm as well as their potential impact on the scalability and adoption of blockchain technology.展开更多
基金the National Natural Science Foundation of China under Grant 61701059,Grant 61941114,and Grant 61831002,in part by the Fundamental Research Funds for the Central Universities of New TeachersProject,in part by the Chongqing Technological Innovation and Application Development Projects under Grant cstc2019jscx-msxm1322,and in part by the Eighteentg Open Foundation of State Key Lab of Integrated Services Networks of Xidian University under Grant ISN20-05.
文摘In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no technical analysis and comparison as a guideline to determine which type of consensus mechanism should be adopted in a specific scenario/application.To this end,this work investigates three mainstream consensus mechanisms in the blockchain,namely,Proof of Work(PoW),Proof of Stake(PoS),and Direct Acyclic Graph(DAG),and identifies their performances in terms of the average time to generate a new block,the confirmation delay,the Transaction Per Second(TPS)and the confirmation failure probability.The results show that the consensus process is affected by both network resource(computation power/coin age,buffer size)and network load conditions.In addition,it shows that PoW and PoS are more sensitive to the change of network resource while DAG is more sensitive to network load conditions.
基金funded by Universiti Teknologi PETRONAS and grants(YUTP-PRG:015PBC-011).
文摘This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is to comprehensively investigate prominent mechanisms’security features and vulnerabilities,emphasizing their security considerations,applications,challenges,and future directions.The existing literature offers valuable insights into various consensus mechanisms’strengths,limitations,and security vulnerabilities and their real-world applications.However,there remains a gap in synthesizing and analyzing this knowledge systematically.Addressing this gap would facilitate a structured approach to understanding consensus mechanisms’security and vulnerabilities comprehensively.The study adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and computer science standards and reviewed 3749 research papers from 2016 to 2024,excluding grey literature,resulting in 290 articles for descriptive analysis.The research highlights an increased focus on blockchain consensus security,energy efficiency,and hybrid mechanisms within 60%of research papers post-2019,identifying gaps in scalability,privacy,and interoperability for future exploration.By synthesizing the existing research and identifying the key trends,this SLR contributes to advancing the understanding of blockchain consensus mechanisms’security and guiding future research and structured innovation in blockchain systems and applications.
基金This work is supported by the National Key R&D Program of China under Grant No.2020AAA0103801Quanlin Li is supported by the National Natural Science Foundation of China under Grant Nos.71671158 and 71932002+1 种基金the Beijing Social Science Foundation Research Base Project under Grant No.19JDGLA004Xiaole Wu is supported by the National Natural Science Foundation of China under Grant No.72025102.
文摘In this paper,we provide a new theoretical framework of pyramid Markov processes to solve some open and fundamental problems of blockchain selfish mining under a rigorous mathematical setting.We first describe a more general model of blockchain selfish mining with both a two-block leading competitive criterion and a new economic incentive mechanism.Then we establish a pyramid Markov process and show that it is irreducible and positive recurrent,and its stationary probability vector is matrix-geometric with an explicitly representable rate matrix.Also,we use the stationary probability vector to study the influence of orphan blocks on the waste of computing resource.Next,we set up a pyramid Markov reward process to investigate the long-run average mining profits of the honest and dishonest mining pools,respectively.As a by-product,we build one-dimensional Markov reward processes and provide some new interesting interpretation on the Markov chain and the revenue analysis reported in the seminal work by Eyal and Sirer(2014).Note that the pyramid Markov(reward)processes can open up a new avenue in the study of blockchain selfish mining.Thus we hope that the methodology and results developed in this paper shed light on the blockchain selfish mining such that a series of promising research can be developed potentially.
文摘The energy use of Bitcoin is fiercely debated among academics,practitioners,and the general public.This debate is often biased and characterized by a lack of understanding.Therefore,I start this paper with a discussion of the fundamentals of Bitcoin,which includes the clarification of widely held misconceptions.Next,I illustrate how Bitcoin is related to energy and describe the underlying incentive mechanism.In the main body of the paper,I discuss various components of Bitcoin’s energy use,including the amount,composition,and geographical distribution of the energy,as well as emerging positive and negative effects.These components are then combined into a comprehensive framework that provides a solid foundation for future academic research and presents practitioners with the big picture of how and why Bitcoin requires energy and whether this can be justified from an environmental point of view.
基金This work was supported in part by the National Natural Science Foundation of P.R.China under Grants[61573076,61703063,61903053]the Science and Technology Research Project of the Chongqing Municipal Education Commission of P.R.China under Grants[KJZD-K201800701,KJQN201900702,KJ1705121,KJ1705139]+1 种基金the Program of Chongqing innovation and entrepreneurship for Returned Overseas Scholars of P.R.China under Grant cx20181102018 Team Building Project for Graduate Tutors in Chongqing under Grant JDDSTD2018001.
文摘PoW(Proof of Work)plays a significant role in most blockchain systems to grant an accounting right over decentralized participants and ensure tamper resistance.Though hash functions are generally exploited for PoW due to their merits on summering,anti-collision,and irreversibility,they cannot certify that the bookkeeper is exactly the worker.Thereafter,such insistence may lead to abuse or even embezzlement of computing power for the benefit of malicious miners.To preserve the functionality of PoW but also bind the miners’signing keys with their works,we build a post-quantum PoW scheme by changing the approximate closest vector norm for probabilistic NTRUSign.Different from the schemes based on hash functions,our scheme takes signing as the proof of work where signature verification is just the evidence of block reward.We also presented a method to adjust the difficulty of signing by modifying the probability of generating a correct signature.The performance of our scheme is also analyzed theoretically and experimentally,which implies its practicability and advantages.
文摘Blockchain technology has gained widespread adoption in recent years due to its ability to enable secure and trans-parent record-keeping and data transfer.A critical aspect of blockchain technology is the use of consensus algorithms,which allow distributed nodes in the network to agree on the state of the blockchain.In this review paper,we exam-ine various consensus algorithms that are used in blockchain systems,including proof-of-work,proof-of-stake,and hybrid approaches.We go over the trade-offs and factors to think about when choosing a consensus algorithm,such as energy efficiency,decentralization,and security.We also look at the strengths and weaknesses of each algorithm as well as their potential impact on the scalability and adoption of blockchain technology.