No system entity within a contemporary distributed cyber system can be entirely trusted. Hence, the classic centralized trust management method cannot be directly applied to it. Blockchain technology is essential to achieving decentralized trust management, its consensus mechanism is useful in addressing large-scale data sharing and data consensus challenges. Herein, an n-party quantum detectable Byzantine agreement (DBA) based on the GHZ state to realize the data consensus in a quantum blockchain is proposed, considering the threat posed by the growth of quantum information technology on the traditional blockchain. Relying on the nonlocality of the GHZ state, the proposed protocol detects the honesty of nodes by allocating the entanglement resources between different nodes. The GHZ state is notably simpler to prepare than other multi-particle entangled states, thus reducing preparation consumption and increasing practicality. When the number of network nodes increases, the proposed protocol provides better scalability and stronger practicability than the current quantum DBA. In addition, the proposed protocol has the optimal fault-tolerant found and does not rely on any other presumptions. A consensus can be reached even when there are n−2 traitors. The performance analysis confirms viability and effectiveness through exemplification. The security analysis also demonstrates that the quantum DBA protocol is unconditionally secure, effectively ensuring the security of data and realizing data consistency in the quantum blockchain.
We propose an application for near-term quantum devices: namely, generating cryptographically certified random bits, to use (for example) in proof-of-stake cryptocurrencies. Our protocol repurposes the existing "quantum supremacy" experiments, based on random circuit sampling, that Google and USTC have successfully carried out starting in 2019. We show that, whenever the outputs of these experiments pass the now-standard Linear Cross-Entropy Benchmark (LXEB), under plausible hardness assumptions they necessarily contain $Ω(n)$ min-entropy, where $n$ is the number of qubits. To achieve a net gain in randomness, we use a small random seed to produce pseudorandom challenge circuits. In response to the challenge circuits, the quantum computer generates output strings that, after verification, can then be fed into a randomness extractor to produce certified nearly-uniform bits -- thereby "bootstrapping" from pseudorandomness to genuine randomness. We prove our protocol sound in two senses: (i) under a hardness assumption called Long List Quantum Supremacy Verification, which we justify in the random oracle model, and (ii) unconditionally in the random oracle model against an eavesdropper who could share arbitrary entanglement with the device. (Note that our protocol's output is unpredictable even to a computationally unbounded adversary who can see the random oracle.) Currently, the central drawback of our protocol is the exponential cost of verification, which in practice will limit its implementation to at most $n\sim 60$ qubits, a regime where attacks are expensive but not impossible. Modulo that drawback, our protocol appears to be the only practical application of quantum computing that both requires a QC and is physically realizable today.
The Internet of Things (IoT) and blockchain, the hottest frontier technologies in recent years, are expected to lead the next technological revolution. Blockchain promises to solve the current challenges encountered by the IoT. However, most of the proposed blockchain-based IoT architectures, which are based on discrete logarithm or large integer factorization problems, are susceptible to quantum attacks. Several quantum-resistant blockchain schemes have recently been proposed. However, the efficiency of their construction or the equipment required is not satisfactory. In this paper, to construct a more efficient postquantum blockchain infrastructure, we propose blockchain architecture for the IoT over the NTRU lattice and provide a cryptographic security proof of the scheme. Attributed to the more efficient underlying lattice structure, our scheme has excellent performance when compared to the existing quantum-resistant blockchain scheme, and we reduce the transaction size from hundreds of megabytes to several kilobytes. To further improve the blockchain's performance, we present the general framework of segregated witnesses and aggregate signatures over the NTRU lattice. Our scheme promises a blockchain solution for resource-constrained environments.
Ang Liu, Xiu‐Bo Chen, Gang Xu, Zhuo Wang · 6 authors
The rapid advancement of quantum technology poses significant security risks to blockchain systems. However, quantum technology can also provide solutions for enhancing blockchain security. In this paper, we propose a quantum... | Find, read and cite all the research you need on Tech Science Press
Heung-No Lee, Young Sik Kim, Dilbag Singh, M. Kaur
Modern societies have adopted government-issued fiat currencies many of which exist today mainly in the form of digits in credit and bank accounts. Fiat currencies are controlled by central banks for economic stimulation and stabilization. Boom-and-bust cycles are created. The volatility of the cycle has become increasingly extreme. Social inequality due to the concentration of wealth is prevalent worldwide. As such, restoring sound money, which provides stored value over time, has become a pressing issue. Currently, cryptocurrencies such as Bitcoin are in their infancy and may someday qualify as sound money. Bitcoin today is considered as a digital asset for storing value. But Bitcoin has problems. The first issue of the current Bitcoin network is its high energy consumption consensus mechanism. The second is the cryptographic primitives which are unsafe against post-quantum (PQ) attacks. We aim to propose Green Bitcoin which addresses both issues. To save energy in consensus mechanism, we introduce a post-quantum secure (self-election) verifiable coin-toss function and novel PQ secure proof-of-computation primitives. It is expected to reduce the rate of energy consumption more than 90 percent of the current Bitcoin network. The elliptic curve cryptography will be replaced with PQ-safe versions. The Green Bitcoin protocol will help Bitcoin evolve into a post-quantum secure network.
This paper presents a new method for quantum identity authentication (QIA) protocols. The logic of classical zero-knowledge proofs (ZKPs) due to Schnorr is applied in quantum circuits and algorithms. This novel approach gives an exact way with which a prover $P$ can prove they know some secret by encapsulating it in a quantum state before sending to a verifier $V$ by means of a quantum channel - allowing for a ZKP wherein an eavesdropper or manipulation can be detected with a fail-safe design. This is achieved by moving away from the hardness of the Discrete Logarithm Problem towards the hardness of estimating quantum states. This paper presents a method with which this can be achieved and some bounds for the security of the protocol provided. With the anticipated advent of a `quantum internet', such protocols and ideas may soon have utility and execution in the real world.
Open access
2 source records
Physical Unclonable Functions (PUFs) and Hardware Security
Maxime Buser, Rafael Dowsley, Muhammed F. Esgin, Clémentine Gritti · 12 authors
Blockchain technology provides efficient and secure solutions to various online activities by utilizing a wide range of cryptographic tools. In this article, we survey the existing literature on post-quantum secure digital signatures that possess exotic advanced features and that are crucial cryptographic tools used in the blockchain ecosystem for (1) account management, (2) consensus efficiency, (3) empowering scriptless blockchain, and (4) privacy. The exotic signatures that we particularly focus on in this work are the following: multi-/aggregate, threshold, adaptor, blind, and ring signatures. Herein the term ”exotic” refers to signatures with properties that are not just beyond the norm for signatures, e.g., unforgeability, but also imbue new forms of functionalities. Our treatment of such exotic signatures includes discussions on existing challenges and future research directions in the post-quantum space. We hope that this article will help to foster further research to make post-quantum cryptography more accessible so that blockchain systems can be made ready in advance of the approaching quantum threats.
With the drive to create a decentralized digital economy, Web 3.0 has become a cornerstone of digital transformation, developed on the basis of computing-force networking, distributed data storage, and blockchain. With the rapid realization of quantum devices, Web 3.0 is being developed in parallel with the deployment of quantum cloud computing and quantum Internet. In this regard, quantum computing first disrupts the original cryptographic systems that protect data security while reshaping modern cryptography with the advantages of quantum computing and communication. Therefore, in this paper, we introduce a quantum blockchain-driven Web 3.0 framework that provides information-theoretic security for decentralized data transferring and payment transactions. First, we present the framework of quantum blockchain-driven Web 3.0 with future-proof security during the transmission of data and transaction information. Next, we discuss the potential applications and challenges of implementing quantum blockchain in Web 3.0. Finally, we describe a use case for quantum non-fungible tokens (NFTs) and propose a quantum deep learning-based optimal auction for NFT trading to maximize the achievable revenue for sufficient liquidity in Web 3.0. In this way, the proposed framework can achieve proven security and sustainability for the next-generation decentralized digital society.
A proof-of-randomness (PoR) protocol is presented as a fair and low energy-cost consensus mechanism for blockchains. Each network node of a blockchain may use a true random number generator (TRNG) and hash algorism to fulfil the PoR protocol. In this paper, we give the consensus mechanism of the PoR protocol, and classify it into a new kind of randomized algorithms called Macau. The PoR protocol could generate a blockchain without any competition of computing power or stake of cryptocurrency. Besides, we give some advantages of integrating quantum random number generator (QRNG) chips into hardware wallets, and also discuss the way to cooperate with quantum key distribution (QKD) technology.
Anupama Ray, Sai Sakunthala Guddanti, Vishnu Ajith, Dhinakaran Vinayagamurthy
Ethereum is one of the most valuable blockchain networks in terms of the total monetary value locked in it, and arguably been the most active network where new blockchain innovations in research and applications are demonstrated. But, this also leads to Ethereum network being susceptible to a wide variety of threats and attacks in an attempt to gain unreasonable advantage or to undermine the value of the users. Even with the state-of-art classical ML algorithms, detecting such attacks is still hard. This motivated us to build a hybrid system of quantum-classical algorithms that improves phishing detection in financial transaction networks. This paper presents a classical ensemble pipeline of classical and quantum algorithms and a detailed study benchmarking existing Quantum Machine Learning algorithms such as Quantum Support Vector Machine and Variational Quantum Classifier. With the current generation of quantum hardware available, smaller datasets are more suited to the QML models and most research restricts to hundreds of samples. However, we experimented on different data sizes and report results with a test data of 12K transaction nodes, which is to the best of the authors knowledge the largest QML experiment run so far on any real quantum hardware. The classical ensembles of quantum-classical models improved the macro F-score and phishing F-score. One key observation is QSVM constantly gives lower false positives, thereby higher precision compared with any other classical or quantum network, which is always preferred for any anomaly detection problem. This is true for QSVMs when used individually or via bagging of same models or in combination with other classical/quantum models making it the most advantageous quantum algorithm so far. The proposed ensemble framework is generic and can be applied for any classification task
Blockchain and other Distributed Ledger Technologies (DLTs) have triggered widespread research and interest. This is due to its ability to create redundant, transparent, and accountable connections in various application domains while utilizing asymmetric cryptography, digital signature, and hash functions. However, the current blockchain system exhibits vulnerability to attacks, especially those staged and actualized using quantum computers leveraging Grover’s and Shor’s algorithms. There is a need to examine the various algorithms of digital signatures, post-quantum generations of public-key cryptography, and their performance to gain insights into the most suitable way to address the issue. In our review, we examine the performance of different post-quantum public-key generation and digital signature algorithms in blockchain and provide a performance comparison of computing time and memory usage. The research presented here includes application domains where post-quantum blockchain may be used.
The blockchain is a distributed storage system of digital assets. This decentralized, non-copyable technology stems from universal standard password algorithm and the consensus mechanism of the game theory. The development of quantum computing poses threat to traditional algorithms of blockchain encryption, including symmetric encryption and hash encryption. Focusing on the traditional blockchain consensus mechanism, this paper designs a new blockchain consensus mechanism, based on the stochasticity, irreversibility, and uncertainty of quantum measurement. In the proposed consensus mechanism, complex calculations and intractability mathematical problems are abandoned. In this way, a huge amount of computing resources is saved, less energy is consumed, the time delay is shortened, and the throughput is increased. The proposed quantum consensus mechanism can withstand 51% attacks.
Due to its minimal energy requirement the PoS consensus protocol has become an attractive alternative to PoW in modern cryptocurrencies. In this protocol the chance of being selected as a block proposer in each round is proportional to the current stake of any node. Thus, nodes with higher stakes will achieve more block rewards, resulting in the so-called rich-getting-richer problem. In this paper, we introduce a new block reward mechanism called the FRD (Fair Reward Distribution) mechanism, in which for each block produced, in addition to a major reward given to the block proposer, a small reward is given to all other nodes. We prove that this reward mechanism makes the PoS protocol fairer in terms of concentration of wealth by developing on the Bagchi-Pal urn model.
Mauritz Kop is TTLF Fellow and Visiting Scholar at Stanford Law School, Stanford University; Founder of MusicaJuridica and strategic intellectual property lawyer at AIRecht, a technology consultancy firm based in Amsterdam. His present cross-disciplinary, comparative research focuses on human-centred artificial intelligence (AI), the Ethical, Legal, Socio-Economic, and Policy Implications of Quantum Technology (Quantum-ELSPI), and sustainable disruptive innovation policy pluralism. Mateo Aboy is Principal Research Scholar in Biomedical Innovation, Precision Medicine, AI & Law at the LML, University of Cambridge and Affiliated Professor and Fellow at the Centre for Advanced Studies in Biomedical Innovation Law (CeBIL), University of Copenhagen. Timo Minssen is Professor of Law and the Founding Director of the Center for Advanced Studies in Biomedical Innovation Law (CeBIL), University of Copenhagen. Specializing in IP, tech-transfer, antitrust and the regulation of health and life science innovation, he is also a senior advisor at the Swedish law firm X-officio and a Quantum Law Researcher at Lund University. Abstract One of the central goals of intellectual property rights (IPRs) and related rights is to incentivize and reward creative and innovative efforts that promote scientific and technical progress and stimulate fair competition through the distribution and commercialization of technologies. Yet, an excessive proliferation of exclusive rights can also result in fundamentally anticompetitive environments with potentially negative effects on scientific research, product development, fair distribution and equitable access to the technology. Hence, a reasonable balance must be found between the stimulation of sustainable innovation and competition, the promotion of scientific research and protection through IPRs. To reconcile these factors, each new technology has led to judicial responses and even modifications to the law. We are on the verge of a technological revolution associated with quantum technologies, including quantum computing and quantum/artificial intelligence hybrids. Its complexity and global significance are creating challenges, which could not have been foreseen when the IP system was developed. This article utilizes the insights gained from qualitative and quantitative studies to (a) inquire which IPRs and related rights are currently directed to quantum computing and (b) examine whether the strategic use of overlapping IPRs might lead to innovation distortions such as excessive anticompetitive effects and underuse associated with property fragmentation. Emphasis is laid on the question if, and if so to what degree, IP portfolio approaches could result in inappropriate proliferations of exclusive rights, raise anticommons concerns and denote unwanted concentrations of first mover market power. It concludes by outlining potential proactive responses to mitigate these risks, while addressing the major future open and closed innovation opportunities, implications and challenges posed by quantum technology in general and quantum computing in particular. Current advances in quantum technology highlight the unique characteristics, promises and perils of quantum technologies—such as the unprecedented capabilities of quantum sensors, secured communications and the potential for quantum computing to solve problems beyond the reach of classical processors by implementing quantum algorithms on programmable quantum computers. The spectrum of potential applications is vast and ranges from uses in health and life sciences (eg, modelling chemical processes at the quantum using quantum simulation) to national security (eg, military uses quantum cryptography, communications and computation). In light of these actual and potential capabilities, national governments have invested over $25 billion into quantum computing research by mid-2021,1 and some reports announce that by September 2021, the quantum technology industry has attracted more than $1 billion in venture capital.2 This will have clear implications not only for the future of business, science, government and the global power game but also for society itself.3 While the predicted consequences of quantum technology remain in part speculative, it becomes increasingly evident that the ethico-legal frameworks for incentivizing, protecting, governing and regulating quantum technologies will have to be carefully studied. These frameworks might potentially have to be adapted—or newly interpreted—considering the new realities presented by second-generation (2G) quantum devices. International organizations, such as the World Economic Forum (WEF), have therefore engaged in developing ‘the first set of principles for responsible design and adoption of quantum computing technologies in order to incentivize the development of the technology while minimizing the possible risks’.4 Consequently, scrutinizing the existing framework for IPRs and how they apply to quantum computing, including their governance and regulatory dimensions, as well the interplay of IPRs with new forms of potentially closed or more decentralized and open innovation systems, are becoming ever more relevant. One of the primary goals of IPRs and related rights, such as patents, copyrights, trade secrets and trade marks, is to reward and protect creative and innovative efforts in order to promote scientific and technical progress, as well as stimulating fair competition through the distribution and commercialization of technologies.5 For example, an effective and predictable patent protection regime is generally regarded as necessary to encourage risky and costly research in complex technologies that take a long time to reach the market but are relatively easy to copy such as many pharmaceuticals. Other IPRs, such as trade secrets, could become more relevant regarding highly complex technologies that are not so easy to copy and face less regulatory barriers. However, overprotection through IPRs can also lead to a situation that would create a fundamentally anticompetitive environment.6 For example, a proliferation of patent rights upstream could potentially hinder essential innovations further downstream in the course of scientific research and product development because each upstream patent allows its owner to create another obstacle on the road to product development, adding to the cost and slowing the pace of downstream innovation.7 Dealing with this potential dilemma, commonly referred to as the ‘Tragedy of the Anticommons’, requires a reasonable balance to be found between the stimulation of innovation competition, the enhancement of scientific research and the careful protection of intellectual property rights.8 To maintain such a reasonable balance, each new technology has involved modifications to the law. This is nothing new. The first patents, during the Industrial Revolution, were mostly directed to mechanical devices and articles of manufacture. When chemical law the existing framework to solve new problems posed by and of based on and by the of and as well as in and have also led to many and a of law and We are currently on the verge of a new technological revolution associated with quantum technologies, including quantum its complexity might create challenges, which could have been foreseen when the system was this this article (a) which IPRs and rights would be to quantum technology and (b) an of whether the strategic use of of IP rights to the of a quantum IP portfolio potentially might lead to anticompetitive of market and competition and In this it would progress in an of quantum quantum will therefore be laid on the question if, and if so to what degree, overlapping IPRs could result in an inappropriate of global exclusive rights for first and in an unwanted of market power. To these this article will first with an of what quantum computing and how it can be will which of IP are at present the of quantum will these the first of on the patent for quantum will use the insights gained from qualitative and quantitative studies to the implications and possible responses to to mitigate and to future based on the of and Quantum computing its from principles of quantum (eg, and the of the Quantum the between and and the of at the beyond classical including such as and the of is the of the the of of such as of and Quantum and general are to be in an that the of at Quantum or are the quantum of can be a or a or a of We this with a a quantum in of possible quantum In to quantum can be while of each This is as quantum quantum to the in which a potential that is in For these are quantum In quantum computing is for some of the problems on which such as and for the of and Quantum are when modelling or of using quantum These at complex However, quantum also have For example, quantum can to complex and such as the but they to these The of artificial intelligence (eg, and quantum and can solve and chemical can problems that are currently not with the of classical computers. AI and quantum computing of based on classical and to artificial AI algorithms using classical with quantum algorithms that principles has the potential to including in the of and computing is to In the between quantum technology and AI the a new on science that quantum quantum and quantum will an in the development of artificial and the of is the between quantum computing and intellectual property Quantum can be by of intellectual and property rights, such as rights patents, copyrights, trade secrets, design rights and trade We which IP rights can be of these be it or We also whether are in protection and whether are IP rights are rights, these as as possible from the of an IP be in and and of protection in the or the Quantum on their in the and on their the of the technology quantum and quantum the of quantum processors such as and quantum the and the the the and quantum the the quantum set quantum quantum quantum the quantum and and quantum computing and the and the actual or of a quantum a quantum a a and a In a is to access the of the quantum in and This is a of through the In are with quantum and AI have to the of the AI system to this of including the that processes the and that are patent so by a can be generally a of and a and technical to technical problems that have been and into of articles of and processes are for patent While and are not might potentially algorithms and to the that is directed to a technical result or and if it is a of an that a technical can be further by the of IP rights, can the of a quantum by rights, design and and creative and algorithms or These can to the potential for the of these algorithms to solve technological problems as and system that technical to a technical The protection for is generally as it is also by the of to the life of the for One of the for this is that the system and the patent system have In quantum computing is more to and than the and It requires more to the than to the a the and devices necessary to become to and as in trade between the and The patent system to incentivize to and market their with the of on It to encourage the of innovative and the of research and development by exclusive rights to the the or its the it to design and and of can be In of and are from The are for patent the technology quantum and quantum the of quantum processors such as and quantum and the and the the the and the the quantum set and quantum The computing can be by as The including its quantum and is also for it the of and Quantum computing algorithms are not they are However, the of quantum algorithms to solve technical problems can potentially be patent These are using and system that to be in an to they the in the and technical in to incentivize and technological progress and of of is to stimulate and of by of to on the of their to the World on and the World creative of and can be by as if they are the of is not its The that is by general principles and are not The are part of the the of an is in a it can be by an can also be by a The are for quantum the quantum and and quantum computing and the and These the of these are of creative and in a of It is possible that for quantum computing will be of or for use with classical computing, it is that and will into the and some for is not by This the question of whether and be by for and of and can be IP whether or patents, in a to trade secrets, which generally on the quantum computing system of It is also possible to from a classical computing into a quantum the In of AI that of the is in the these IP a of potential IP rights potentially in the that to be including a on the the for the of AI and are concerns and of is a of in the existing because they are and not for AI and for to be a or even a to for quantum computing that and In quantum computing IP this is for IP It can be or IP rights on the can also be and into the or by upstream or downstream be The and and society from a IP rights can only be by such as or or to rights and and be These in an of and patents, of a quantum can trade in some trade and trade with potentially of law and national security beyond the of the IP a in technological a is the with AI and some technologies, the of quantum computing systems, with the of trade rights, could a trade secrets to protect and quantum computing applications and quantum This might of of technology to the and that a trade not protect This IP can be by that unwanted a quantum and design can be and modelling on the for which protection is by an of IP such as design rights, rights and trade using a of IP rights to and protect the of the IP portfolio of the quantum owner could result in an of global exclusive rights for first of essential in is a that are in IP protection from is a potential of IP protection this new of rights not Other quantum technologies—such as quantum quantum and the quantum for IP protection using the of IP a innovation law future quantum to be and Its and could be by an of IP rights, with each The to quantum sensors, quantum and and devices with the of quantum technology. it is the with technologies, IP framework is not with quantum technology in IP is to be an in time and the that can be for the essential of quantum technologies be to equitable a and sustainable innovation policy it could be that IP rights not be to the of their and It might well be to in a quantum technology It could be to such in an intellectual property have been have further that quantum technology and not to be by IP or beyond the it has been that is ‘Tragedy of the on quantum technology be IP incentivize market and market at the For to encourage fair competition and market IP law to be with antitrust The question is whether the in and IP overprotection could create for market and raise concerns regarding fair competition, of and the of new might hinder innovation and could potentially lead to the ‘Tragedy of the that have been for many in the In this an anticommons which would underuse by rights by a of IP portfolio and patent could progress in an of quantum quantum In trade in property anticommons In protection might have a negative on the and protection to the that are in the of technologies and to remain It is to and carefully these and to take proactive it necessary based on the insights gained from technological approaches must also take into and the for of IP These can have effects if and with the of the IP system and its forms of and forms of governing IP as well as to IP protection must be on the and a of and it is in further that such approaches are by studies that and While this apply to IPRs and rights, the will the of such an that has on the and in quantum We a patent to including the has been the over the for quantum and are the quantum what are to protect these more IP research to these of it is for and to they can to existing and regulatory with reasonable of in this present from a more patent on the of quantum computing with the of from the actual in this technical the use the International by the of The a system to to technical that is are into and The is an of the It is by the and & and the by In this patent use of the system to related to quantum patent the new to the technical of quantum computing to the quantum computing with a of the that have been by the and computing, based on by the of the patent For the of patent are as the of and We a of quantum computing from and that of these have been of the patent protection for quantum computing has in the of the patent that these quantum computing with directed to and for quantum processors or (eg, quantum quantum quantum and quantum (eg, of quantum such as quantum quantum and quantum access and of quantum algorithms (eg, algorithms based on quantum applications of the quantum and and quantum and quantum (eg, quantum computing, for and quantum and quantum of in quantum computing at the and The of that the and are currently over quantum computing of the in quantum computing patent has of that the of in was the as in in the the of quantum computing from to This to a of which is than the for quantum technologies over this in the has been the of for quantum computing The has of the the the has only that have been quantum computing, has been the of for of the quantum technology but in the of quantum computing, it for a to the the patent has the in the of quantum computing in or that not are to result in distortions regarding the of patent for for patent law (eg, for quantum to be of the the patent for and quantum computing as well as the of their that and currently have the patent in quantum These with were in the of quantum computing and some of the with However, to they have their over the patent quantum and of that new can patent portfolio this is not only possible for such as which in and by based on the of but also for an a firm on quantum processors for quantum computing systems, the patent of technology such as and This is an IP is new to the to their to their innovations to For example, the to design and its This has in the of of the quantum a quantum on quantum processors for quantum computing and a for quantum in patent on quantum such as and can their quantum computing from their and but these new have to from based on the of their IP the of the and the of or a on a new on quantum computing, it the potential for technology and disruptive innovation from new on quantum of the patent less than in the classical computing and In to and and that and new are the For billion more quantum computing than market market or billion market In that patent protection will be more for the new and and on quantum (eg, than for the technology currently the classical computing and the of quantum that have and are in the of the patent applications have not been and are also part of the This is highly relevant from a policy to trade secrets, these patent to raise the of for patent they from these and it more to of protection for patent In this to their which in effective patent and for trade secrets to and and quantum computing the of quantum computing that the patent system is in a technical trade secrets be a IP to the of the (eg, the quantum can be and secured at the from the and even these can be access through the with the and the that and be in the In it is that the quantum computing that in this will be in the by the time the market a to the by technology market patent rights would incentivize to patent protection it requires in for in of trade secrets that can be as long as the secrets are secured and their of from their market and patent the have these of and are more to patent their in order to the exclusive property rights and venture in a are in the In this a for are also to their through the patent system as to as trade These be into when and and regulatory related to quantum has that it is for IP frameworks to disruptive technologies and their on the IP as it is to the of the IP system on the of such technologies. to encourage fair competition and market IP law to be and with regulatory law and antitrust as well as the by and These approaches in for such as the and the global competition in quantum technology that governments and will have to carefully such and the interplay between IPRs and related rights with quantum For quantum IPRs be as part of the new IP which regulatory such as the AI the the and to the This IP promises an intellectual property system to to technologies advances in and The to set global in The in the protection of the of IP by and the of and of IP a global to the pace of innovation in the Quantum was to IP protection for and and including the of the These could apply to and is when such Yet, the of exclusive with or to encourage and innovation the quantum In this a innovation that possible (eg, access and and (eg, and reward and that is to and decentralized innovation However, it is also evident that many will face and challenges, from potential of the in of the or that ‘Tragedy of the to global competition and with to the protection and of quantum technology. This not that new approaches quantum technology not be might be if problems with the IP system are or Yet, patent on quantum computing the patent system is as to the system be based on and of to the IP system to promote the and the challenges posed by quantum computing must also be based on a of the IP how the forms of protection and to what a and of IP and can mitigate unwanted While for anticommons and the related of the patent to have in the technology patent for the quantum computing is not a and as actual or potential by patent protection or of the IP such as the of the IP system for unwanted overlapping can be from and of the patent can be with and the IP for the patent this would the and of the and of the on the as well as careful to the and into the patent at the patent It is clear that this would also patent the and in the the of the patent or of the to the of by of the are more or less and a more of each of the have a or more on the of protection of patents, the and of what as well as on the of protection for technologies or even IP For the future of quantum technologies and quantum computing, the question is to the and in order to the for the enhancement of innovation and the of upstream patent some the of an with to the in a of These ‘the effects of factors, such as for scientific and the of innovation, and that might for technological could also be the framework for research and or possible that can be found the of patent In that some have a more and but of competition or antitrust Other and to such as and The in the of patent or These would the exclusive rights but the into While it how these are in technology these to or in the patent system and potential anticommons by it possible for patent to use forms of or to their rights into property rights not be to solve problems that they were to on the IP rights not be the only not the innovation and could apply innovation policy and IP such as antitrust law and and as well as and to and balance the effects of innovation the innovation and reward and industry and more between when regulatory IP rights might be less in a and and distribution become in the if a fair global distribution of quantum technologies is the it will be to on and technology to and on a This article qualitative on potential IP overprotection of quantum technologies to the IPRs could denote an inappropriate of global exclusive rights for first result in market and for quantum and to anticommons concerns including underuse by quantitative that IP overprotection requires a of existing IP for quantum technologies, to or IP and an unwanted of market power. In to to these the article on patent to quantum computers. found that to be so such patent overprotection problems in the quantum computing to the that their consequences would hinder innovation in this of quantum as more and more quantum patent the an quantum computing However, in by trade secrets or secrets, remain the of as these innovations is not by set and be or to potential innovation by IPRs and antitrust in the quantum computing must maintain a and with and In this quantum is the In law policy a regime that a between and overprotection of regime that for an innovation while and to first and their The that this is not a is by IP which a that between of and In have to regarding for open or closed innovation systems, into to access and In it is to these and and to take proactive it necessary based on the insights gained from research, and technological approaches take into and the for of IP protection and their interplay with antitrust in quantum computing, quantum and quantum the time is for research and the to new and intellectual property that encourage competition and incentivize sustainable These must the balance between rights technology national security policy and the of a global quantum while rights and and quantum and law further the of IP portfolio trade and secrets, patent and new of property industry and quantum and research These are for further scientific
We propose a new, unifying framework that yields an array of cryptographic primitives with certified deletion. These primitives enable a party in possession of a quantum ciphertext to generate a classical certificate that the encrypted plaintext has been information-theoretically deleted, and cannot be recovered even given unbounded computational resources. - For X \in {public-key, attribute-based, fully-homomorphic, witness, timed-release}, our compiler converts any (post-quantum) X encryption to X encryption with certified deletion. In addition, we compile statistically-binding commitments to statistically-binding commitments with certified everlasting hiding. As a corollary, we also obtain statistically-sound zero-knowledge proofs for QMA with certified everlasting zero-knowledge assuming statistically-binding commitments. - We also obtain a strong form of everlasting security for two-party and multi-party computation in the dishonest majority setting. While simultaneously achieving everlasting security against all parties in this setting is known to be impossible, we introduce everlasting security transfer (EST). This enables any one party (or a subset of parties) to dynamically and certifiably information-theoretically delete other participants' data after protocol execution. We construct general-purpose secure computation with EST assuming statistically-binding commitments, which can be based on one-way functions or pseudorandom quantum states. We obtain our results by developing a novel proof technique to argue that a bit b has been information-theoretically deleted from an adversary's view once they output a valid deletion certificate, despite having been previously information-theoretically determined by the ciphertext they held in their view. This technique may be of independent interest.
The examination investigates the joining of quantum-safe cryptographic calculations into blockchain innovation, zeroing in on grid-based cryptography and hash-based marks. Because of the inescapable danger presented by quantum processing, this study proposes a quantum-safe blockchain system intended to upgrade the security and flexibility of circulated records. The cross-section-based cryptography calculation uses the computational intricacy of grid issues, offering protection from quantum goes like Shor's calculation. Simultaneously, hash-based marks give lightweight and quantum-safe choices for advanced marks, supporting the general validity of blockchain exchanges. The examination includes a multi-staged approach, incorporating a complete writing survey, hypothetical system improvement, algorithmic execution, and exhaustive investigation of versatility, execution, and information security. Reproduction results will illuminate ensuing equipment executions, approving the down-to-earth attainability of the proposed quantum-safe blockchain. Besides, the review digs into moral and administrative contemplations, adding to the foundation of capable rules for quantum-safe blockchain innovation. Insights into the performance of lattice-based cryptography and hash-based signatures, as well as the provision of a blueprint for future research in quantum-resistant distributed ledger systems, are among the anticipated contributions. The powerful idea of quantum advancements and blockchain requires continuous investigation, and the exploration makes way for future examinations concerning quantum-safe agreement components, upgraded Quantum Key Dispersion, and interdisciplinary coordinated efforts.
Blockchain-based platforms utilise cryptographic protocols to enforce the correct behaviour of users, as well as to guarantee a sufficient level of protection against malicious adversaries. Cryptography is, however, an ever-evolving discipline, and any breakthrough would have immediate consequences on the security of blockchain-based applications. A possible threat currently under investigation is given by the development of quantum computers, since several wide-adopted cryptographic protocols have been proved to be unsafe against quantum-capable adversaries. In this work, we propose a novel approach for the management of cryptographic primitives in smart-contract-based ledgers, discussing how it fits in both a (partially) permissioned and a fully permissionless setting. The cryptographic protocols are managed in a flexible manner via a set of smart-contracts defined on the ledger itself, in this way the choice of algorithms and parameters can change quickly. Among the advantages of this approach, we remark how it allows designing an adaptive post-quantum-based blockchain that keeps up with ongoing technological advances. In general, the introduction of new features and the application of fixes to a blockchain cause forks in the chain, which may cause major disruptions. The use of smart contracts in blockchain management allows to avoid this problem, dynamically introducing new protocols or deprecating old ones without compromising previous data. The Cryptographic Kernel approach has been adopted by Quadrans, an open-source, public, decentralised smart-contract-based blockchain with a specific focus on the needs of industry, complex supply chains, and IOT devices.
As emerging next-generation information technologies, blockchains have unique advantages in information transparency and transaction security. They have attracted great attentions in social and financial fields. However, the rapid development of quantum computation and the impending realization of quantum supremacy have had significant impacts on the advantages of traditional blockchain based on traditional cryptography. Here, we propose a blockchain algorithm based on asymmetric quantum encryption and a stake vote consensus algorithm. The algorithm combines a consensus algorithm based on the delegated proof of stake with node behaviour and Borda count (DPoSB) and quantum digital signature technology based on quantum state computational distinguishability with a fully flipped permutation ([Formula: see text]) problem. DPoSB is used to generate blocks by voting, while the quantum signature applies quantum one-way functions to guarantee the security of transactions. The analysis shows that this combination offers better protection than other existing quantum-resistant blockchains. The combination can effectively resist the threat of quantum computation on blockchain technology and provide a new platform to ensure the security of blockchain.
Smart contracts are cryptographic protocols that are enforced without a judiciary. Smart contracts are used occasionally in Bitcoin and are prevalent in Ethereum. Public quantum money improves upon cash we use today, yet the current constructions do not enable smart contracts. In this work, we define and introduce quantum payment schemes, and show how to implement prudent contracts -- a non-trivial subset of the functionality that a network such as Ethereum provides. Examples discussed include: multi-signature wallets in which funds can be spent by any 2-out-of-3 owners; restricted accounts that can send funds only to designated destinations; and "colored coins" that can represent stocks that can be freely traded, and their owner would receive dividends. Our approach is not as universal as the one used in Ethereum since we do not reach a consensus regarding the state of a ledger. We call our proposal prudent contracts to reflect this. The main building block is either quantum tokens for digital signatures (Ben-David and Sattath QCrypt'17, Coladangelo et al. Crypto'21), semi-quantum tokens for digital signatures (Shmueli'22) or one-shot signatures (Amos et al. STOC'20). The solution has all the benefits of public quantum money: no mining is necessary, and the security model is standard (e.g., it is not susceptible to 51\% attacks, as in Bitcoin). Our one-shot signature construction can be used to upgrade the Bitcoin network to a quantum payment scheme. Notable advantages of this approach are: transactions are locally verifiable and without latency, the throughput is unbounded, and most importantly, it would remove the need for Bitcoin mining. Our approach requires a universal large-scale quantum computer and long-term quantum memory; hence we do not expect it to be implementable in the next few years.
Muhammad Asad Ullah, Jason William Setiawan, Junaid ur Rehman, Hyundong Shin
Blockchain has revolutionized many fields, such as distributed sensor networks, finance, and cryptocurrency. Consensus between distributed network nodes is at the core of such blockchain technologies. The three primary performance measures for any consensus algorithm are scalability, security, and decentralization. This paper evaluates the usefulness and practicality of quantum consensus algorithms for blockchain-enhanced sensor, and computing networks and evaluates them against the aforementioned performance measures. In particular, we investigate their noise robustness against quantum decoherence in quantum processors and over fiber-optic channels. We observe that the quantum noise generally increases the error rate in the list distribution. However, the effect is variable on different quantum consensus schemes. For example, the entanglement-free scheme is more affected than entanglement-based schemes for the local noise cases, while in the case of noisy optical fiber links, the effect is prominent on all quantum consensus schemes. We infer that the current quantum protocols with noisy intermediate-scale quantum devices and noisy quantum communication can only be employed for modular units in intraenterprise-level blockchain, such as Zilliqa, for sensor, and computing networks.
Robert Benkoczi, Daya Ram Gaur, Naya Nagy, Marius Nagy · 5 authors
This paper studies the effect of quantum computers on Bitcoin mining. The shift in computational paradigm towards quantum computation allows the entire search space of the golden nonce to be queried at once by exploiting quantum superpositions and entanglement. Using Grover’s algorithm, a solution can be extracted in time O(2256/t), where t is the target value for the nonce. This is better using a square root over the classical search algorithm that requires O(2256/t) tries. If sufficiently large quantum computers are available for the public, mining activity in the classical sense becomes obsolete, as quantum computers always win. Without considering quantum noise, the size of the quantum computer needs to be ≈104 qubits.
Quantum entanglement has shown distinguished features beyond any classical state. Many methods have been presented to verify unknown entanglement with the complete information about the density matrices by quantum state tomography. In this work, we aim to identify unknown entanglement with only partial information of the state space. The witness consists of a generalized Greenberger-Horne-Zeilinger-like paradox expressed by Pauli observables, and a nonlinear entanglement witness expressed by density matrix elements. First, we verify unknown bipartite entanglement and study the robustness of entanglement witnesses against the white noise. Second, we generalize such verification to partially unknown multipartite entangled states, including the Greenberger-Horne-Zeilinger-type and W-type states. Third, we give a quantum-information application related to the quantum zero-knowledge proof. It further provides a useful method in blindly verifying universal quantum computation resources. These results may be interesting in entanglement theories, quantum communication, and quantum networks.
Sikha Pentyala, Davis Railsback, Ricardo Maia, Rafael Dowsley · 7 authors
In the classical setting of differential privacy, a privacy-preserving query is performed on a private database, after which the query result is released to the analyst; a differentially private query ensures that the presence of a single database entry is protected from the analyst’s view. In this work, we contribute the first definitional framework for differential privacy in the trusted curator setting (Fig. 1); clients submit private inputs to the trusted curator, which then computes individual outputs privately returned to each client. The adversary is more powerful than the standard setting; it can corrupt up to n-1 clients and subsequently decide inputs and learn outputs of corrupted parties. In this setting, the adversary also obtains leakage from the honest output that is correlated with a corrupted output. Standard differentially private mechanisms protect client inputs but do not mitigate output correlation leaking arbitrary client information, which can forfeit client privacy completely. We initiate the investigation of a novel notion of correlated-output differential privacy to bound the leakage from output correlation in the trusted curator setting. We define the satisfaction of both standard and correlated-output differential privacy as round differential privacy and highlight the relevance of this novel privacy notion to all application domains in the trusted curator model. \nWe explore round differential privacy in traditional "dark pool" market venues, which promise privacy-preserving trade execution to mitigate front-running; privately submitted trade orders and trade execution are kept private by the trusted venue operator. We observe that dark pools satisfy neither classic nor correlated-output differential privacy; in markets with low trade activity, the adversary may trivially observe recurring, honest trading patterns, and anticipate and front-run future trades. In response, we present the first round differentially private market mechanisms that formally mitigate information leakage from all trading activity of a user. This is achieved with fuzzy order matching, inspired by the standard randomized response mechanism; however, this also introduces a liquidity mismatch as buy and sell orders are not guaranteed to execute pairwise, thereby weakening output correlation; this mismatch is compensated for by a round differentially private liquidity provider mechanism, which freezes a noisy amount of assets from the liquidity provider for the duration of a privacy epoch, but leaves trader balances unaffected. We propose oblivious algorithms for realizing our proposed market mechanisms with secure multi-party computation (MPC) and implement these in the Scale-Mamba Framework using Shamir Secret Sharing based MPC. We demonstrate practical, round differentially private trading with comparable throughput as prior work implementing (traditional) dark pool algorithms in MPC; our experiments demonstrate practicality for both traditional finance and decentralized finance settings.
The methods of data verification are discussed, which are intended for the distant control of autonomous mobile robotic agents via networks, combining optical data links. The problem of trust servers is considered for position verification and position-based cryptography tasks. In order to obtain flexible quantum and classical verification procedures, one should use the collective interaction of agents and network nodes, including some elements of the blockchain. Multiple-valued logic functions defined within discrete k-valued Allen–Givone algebra are proposed for the logically linked list of entries and the distributed ledger, which can be used for distant data verification and breakdown restoration in mobile agents with the help of partner network nodes. A distributed ledger scheme involves the assigning by distant partners of random hash values, which further can be used as keys for access to a set of distributed data storages, containing verification and restoration data. Multiple-valued logic procedures are simple and clear enough for high-dimensional logic modelling and for the design of combined quantum and classical protocols.