scholarly journals Towards Quantum-Secured Permissioned Blockchain: Signature, Consensus, and Logic

Entropy ◽  
2019 ◽  
Vol 21 (9) ◽  
pp. 887 ◽  
Author(s):  
Xin Sun ◽  
Mirek Sopek ◽  
Quanlong Wang ◽  
Piotr Kulicki
Keyword(s):  
Quantum Key Distribution ◽  
Consensus Algorithm ◽  
Quantum Computers ◽  
Signature Scheme ◽  
Consensus Protocol ◽  
Safeguard Measures ◽  
Blockchain Technology ◽  
Scripting Language ◽  
Near Future ◽  
Digital Signature Scheme

While Blockchain technology is universally considered as a significant technology for the near future, some of its pillars are under a threat of another thriving technology, Quantum Computing. In this paper, we propose important safeguard measures against this threat by developing a framework of a quantum-secured, permissioned blockchain called Logicontract (LC). LC adopts a digital signature scheme based on Quantum Key Distribution (QKD) mechanisms and a vote-based consensus algorithm to achieve consensus on the blockchain. The main contribution of this paper is in the development of: (1) unconditionally secure signature scheme for LC which makes it immune to the attack of quantum computers; (2) scalable consensus protocol used by LC; (3) logic-based scripting language for the creation of smart contracts on LC; (4) quantum-resistant lottery protocol which illustrates the power and usage of LC.

scholarly journals Enable Fair Proof-of-Work (PoW) Consensus for Blockchains in IoT by Miner Twins (MinT)

2021 ◽  
Vol 13 (11) ◽  
pp. 291
Author(s):  
Qian Qu ◽  
Ronghua Xu ◽  
Yu Chen ◽  
Erik Blasch ◽  
Alexander Aved
Keyword(s):  
Singular Spectrum Analysis ◽  
Consensus Algorithm ◽  
Security And Privacy ◽  
Consensus Protocol ◽  
Computing Power ◽  
Blockchain Technology ◽  
Digital Twins ◽  
Operational Characteristics ◽  
Promising Solution ◽  
Cloud Servers

Blockchain technology has been recognized as a promising solution to enhance the security and privacy of Internet of Things (IoT) and Edge Computing scenarios. Taking advantage of the Proof-of-Work (PoW) consensus protocol, which solves a computation intensive hashing puzzle, Blockchain ensures the security of the system by establishing a digital ledger. However, the computation intensive PoW favors members possessing more computing power. In the IoT paradigm, fairness in the highly heterogeneous network edge environments must consider devices with various constraints on computation power. Inspired by the advanced features of Digital Twins (DT), an emerging concept that mirrors the lifespan and operational characteristics of physical objects, we propose a novel Miner Twins (MinT) architecture to enable a fair PoW consensus mechanism for blockchains in IoT environments. MinT adopts an edge-fog-cloud hierarchy. All physical miners of the blockchain are deployed as microservices on distributed edge devices, while fog/cloud servers maintain digital twins that periodically update miners’ running status. By timely monitoring of a miner’s footprint that is mirrored by twins, a lightweight Singular Spectrum Analysis (SSA)-based detection achieves the identification of individual misbehaved miners that violate fair mining. Moreover, we also design a novel Proof-of-Behavior (PoB) consensus algorithm to detect dishonest miners that collude to control a fair mining network. A preliminary study is conducted on a proof-of-concept prototype implementation, and experimental evaluation shows the feasibility and effectiveness of the proposed MinT scheme under a distributed byzantine network environment.

A Brief Analysis of Blockchain Algorithms and Its Challenges

2019 ◽  
pp. 69-85
Author(s):  
Rajalakshmi Krishnamurthi ◽  
Tuhina Shree
Keyword(s):  
Internet Of Things ◽  
Financial Services ◽  
Distributed Database ◽  
Consensus Algorithm ◽  
Central Authority ◽  
Consensus Protocol ◽  
Consensus Algorithms ◽  
The Core ◽  
Blockchain Technology ◽  
Comparison Algorithms

Blockchain is the world's most trusted service. It serves as a ledger that allows transaction to take place in a decentralized manner. There are so many applications based on blockchain technology, including those covering numerous fields like financial services, non-financial services, internet of things (IoT), and so on. Blockchain combines a distributed database and decentralized ledger without the need of verification by central authority. This chapter surveys the different consensus algorithms, blockchain challenges, and their scope. There are still many challenges of this technology, such as scalability and security problems, waiting to be overcome. The consensus algorithms of blockchain are proof of work (POW), proof of stake (POS), ripple protocol consensus algorithm (RPCA), delegated proof of stake (dPOS), stellar consensus protocol (SCP), and proof of importance (POI). This chapter discusses the core concept of blockchain and some mining techniques, consensus problems, and consensus algorithms and comparison algorithms on the basis of performance.

scholarly journals Committing to quantum resistance: a slow defence for Bitcoin against a fast quantum computing attack

2018 ◽  
Vol 5 (6) ◽  
pp. 180410 ◽  
Author(s):  
I. Stewart ◽  
D. Ilie ◽  
A. Zamyatin ◽  
S. Werner ◽  
M. F. Torshizi ◽  
...  
Keyword(s):  
Quantum Computing ◽  
Digital Signature ◽  
Public Key Cryptography ◽  
Public Key ◽  
Quantum Computers ◽  
Signature Scheme ◽  
Integer Factorization ◽  
Digital Signature Algorithm ◽  
Mathematical Problems ◽  
Digital Signature Scheme

Quantum computers are expected to have a dramatic impact on numerous fields due to their anticipated ability to solve classes of mathematical problems much more efficiently than their classical counterparts. This particularly applies to domains involving integer factorization and discrete logarithms, such as public key cryptography. In this paper, we consider the threats a quantum-capable adversary could impose on Bitcoin, which currently uses the Elliptic Curve Digital Signature Algorithm (ECDSA) to sign transactions. We then propose a simple but slow commit–delay–reveal protocol, which allows users to securely move their funds from old (non-quantum-resistant) outputs to those adhering to a quantum-resistant digital signature scheme. The transition protocol functions even if ECDSA has already been compromised. While our scheme requires modifications to the Bitcoin protocol, these can be implemented as a soft fork.

scholarly journals Enable Fair Proof-of-Work (PoW) Consensus for Blockchains in IoT by Miner Twins (MinT)

2021 ◽  
Author(s):  
Qian Qu ◽  
Ronghua Xu ◽  
Yu Chen ◽  
Erik Blasch ◽  
Alexander Aved
Keyword(s):  
Singular Spectrum Analysis ◽  
Consensus Algorithm ◽  
Security And Privacy ◽  
Consensus Protocol ◽  
Computing Power ◽  
Blockchain Technology ◽  
Digital Twins ◽  
Operational Characteristics ◽  
Promising Solution ◽  
Cloud Servers

Blockchain technology has been recognized as a promising solution to enhance the security and privacy of Internet of Things (IoT) and Edge Computing scenarios. Taking advantage of the Proof-of-Work (PoW) consensus protocol, which solves a computation intensive hashing puzzle, Blockchain assures the security of the system by establishing a digital ledger. However, the computation intensive PoW favors members possessing more computing power. In the IoT paradigm, fairness in the highly heterogeneous network edge environments must consider devices with various constraints on computation power. Inspired by the advanced features of Digital Twins (DT), an emerging concept that mirrors the lifespan and operational characteristics of physical objects, we propose a novel Miner-Twins (MinT) architecture to enable a fair PoW consensus mechanism for blockchains in IoT environments. MinT adopts an edge-fog-cloud hierarchy. All physical miners of the blockchain are deployed as microservices on distributed edge devices, while fog/cloud servers maintain digital twins that periodically update miners’ running status. By timely monitoring miner’s footage that is mirrored by twins, a lightweight Singular Spectrum Analysis (SSA) based detection achieves to identify individual misbehaved miners that violate fair mining. Moreover, we also design a novel Proof-of-Behavior (PoB) consensus algorithm to detect byzantine miners that collude to compromise a fair mining network. A preliminary study is conducted on a proof-of-concept prototype implementation, and experimental evaluation shows the feasibility and effectiveness of proposed MinT scheme under a distributed byzantine network environment.

A Brief Analysis of Blockchain Algorithms and Its Challenges

2021 ◽  
pp. 23-39
Author(s):  
Rajalakshmi Krishnamurthi ◽  
Tuhina Shree
Keyword(s):  
Internet Of Things ◽  
Financial Services ◽  
Distributed Database ◽  
Consensus Algorithm ◽  
Central Authority ◽  
Consensus Protocol ◽  
Consensus Algorithms ◽  
The Core ◽  
Blockchain Technology ◽  
Comparison Algorithms

Blockchain is the world's most trusted service. It serves as a ledger that allows transaction to take place in a decentralized manner. There are so many applications based on blockchain technology, including those covering numerous fields like financial services, non-financial services, internet of things (IoT), and so on. Blockchain combines a distributed database and decentralized ledger without the need of verification by central authority. This chapter surveys the different consensus algorithms, blockchain challenges, and their scope. There are still many challenges of this technology, such as scalability and security problems, waiting to be overcome. The consensus algorithms of blockchain are proof of work (POW), proof of stake (POS), ripple protocol consensus algorithm (RPCA), delegated proof of stake (dPOS), stellar consensus protocol (SCP), and proof of importance (POI). This chapter discusses the core concept of blockchain and some mining techniques, consensus problems, and consensus algorithms and comparison algorithms on the basis of performance.

scholarly journals Blockchain Applications in Agribusiness: A Systematic Review

2021 ◽  
Vol 13 (4) ◽  
pp. 95
Author(s):  
Geneci da Silva Ribeiro Rocha ◽  
Letícia de Oliveira ◽  
Edson Talamini
Keyword(s):  
Complex System ◽  
Systematic Review ◽  
Web Of Science ◽  
Scientific Literature ◽  
Early Stage ◽  
Technological Development ◽  
Economic Sectors ◽  
Future Studies ◽  
Blockchain Technology ◽  
Near Future

Blockchain is a technology that can be applied in different sectors to solve various problems. As a complex system, agribusiness presents many possibilities to take advantage of blockchain technology. The main goal of this paper is to identify the purposes for which blockchain has been applied in the agribusiness sector, for which a PRISMA-based systematic review was carried out. The scientific literature corpus was accessed and selected from Elsevier’s Scopus and ISI of Knowledge’s Web of Science (WoS) platforms, using the PRISMA protocol procedures. Seventy-one articles were selected for analysis. Blockchain application in agribusiness is a novel topic, with the first publication dating from 2016. The technological development prevails more than blockchain applications since it has been addressed mainly in the Computer Sciences and Engineering. Blockchain applications for agribusiness management of financial, energy, logistical, environmental, agricultural, livestock, and industrial purposes have been reported in the literature. The findings suggest that blockchain brings many benefits when used in agribusiness supply chains. We concluded that the research on blockchain applications in agribusiness is only at an early stage, as many prototypes are being developed and tested in the laboratory. In the near future, blockchain will be increasingly applied across all economic sectors, including agribusiness, promoting greater reliability and agility in information with a reduced cost. Several gaps for future studies were observed, with significant value for science, industry, and society.

scholarly journals Numerical finite-key analysis of quantum key distribution

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Darius Bunandar ◽  
Luke C. G. Govia ◽  
Hari Krovi ◽  
Dirk Englund
Keyword(s):  
Finite Number ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Numerical Approach ◽  
Asymptotic Formulas ◽  
Quantum Computers ◽  
Secure Communications ◽  
Quantum Relative Entropy ◽  
Asymptotic Equipartition Property ◽  
Optimization Solvers

AbstractQuantum key distribution (QKD) allows for secure communications safe against attacks by quantum computers. QKD protocols are performed by sending a sizeable, but finite, number of quantum signals between the distant parties involved. Many QKD experiments, however, predict their achievable key rates using asymptotic formulas, which assume the transmission of an infinite number of signals, partly because QKD proofs with finite transmissions (and finite-key lengths) can be difficult. Here we develop a robust numerical approach for calculating the key rates for QKD protocols in the finite-key regime in terms of two semi-definite programs (SDPs). The first uses the relation between conditional smooth min-entropy and quantum relative entropy through the quantum asymptotic equipartition property, and the second uses the relation between the smooth min-entropy and quantum fidelity. The numerical programs are formulated under the assumption of collective attacks from the eavesdropper and can be promoted to withstand coherent attacks using the postselection technique. We then solve these SDPs using convex optimization solvers and obtain numerical calculations of finite-key rates for several protocols difficult to analyze analytically, such as BB84 with unequal detector efficiencies, B92, and twin-field QKD. Our numerical approach democratizes the composable security proofs for QKD protocols where the derived keys can be used as an input to another cryptosystem.

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