Cryptographic Primitives in Blockchain Technology

Author(s):  
Andreas Bolfing

Many online applications, especially in the financial industries, are running on blockchain technologies in a decentralized manner, without the use of an authoritative entity or a trusted third party. Such systems are only secured by cryptographic protocols and a consensus mechanism. As blockchain-based solutions will continue to revolutionize online applications in a growing digital market in the future, one needs to identify the principal opportunities and potential risks. Hence, it is unavoidable to learn the mathematical and cryptographic procedures behind blockchain technology in order to understand how such systems work and where the weak points are. The book provides an introduction to the mathematical and cryptographic concepts behind blockchain technologies and shows how they are applied in blockchain-based systems. This includes an introduction to the general blockchain technology approaches that are used to build the so-called immutable ledgers, which are based on cryptographic signature schemes. As future quantum computers will break some of the current cryptographic primitive approaches, the book considers their security and presents the current research results that estimate the impact on blockchain-based systems if some of the cryptographic primitive break. Based on the example of Bitcoin, it shows that weak cryptographic primitives pose a possible danger for the ledger, which can be overcome through the use of the so-called post-quantum cryptographic approaches which are introduced as well.

Author(s):  
Nigel J. Lockett ◽  
David H. Brown

Against a background of the low engagement of small to medium-sized enterprises (SMEs) in e-business, this chapter investigates the impact of e-aggregation applications, provided by emerging vertical application service providers (VSP), and defined as “an e-business application, promoted by a trusted third party, which engages a significant number of SMEs by addressing an important shared business concern within an aggregation”. By conducting quantitative surveys of four aggregations of SMEs using these applications (users) and comparing these results with similar enterprises who are not (non-users) the research takes a deliberate SME perspective.


2012 ◽  
Vol 490-495 ◽  
pp. 914-918 ◽  
Author(s):  
Bao Yuan Kang

A verifiably encrypted signature scheme involves a signer, a verifier, and an adjudicator. It can convince a verifier that a given ciphertext is an encryption of signature on a given message. At a later stage on agreed or in case of dispute, the adjudicator can extract and give the signer's signature to the verifier. In existing verifiably encrypted signatures, the adjudicator is assumed to be a trusted third party who will not conspire with either of the two parties involved. Obviously, this assumption is naive. In this paper, we propose two new types of verifiably encrypted signature schemes. They can resolve the problem that the adjudicator may collaborate with the verifier. We also analyze the security of the proposed schemes.


2018 ◽  
Vol 33 (2) ◽  
pp. 105-125 ◽  
Author(s):  
Darcy W.E. Allen ◽  
Chris Berg ◽  
Mikayla Novak

This paper incorporates blockchain activities into the broader remit of entangled political economy theory, emphasising economic and other social phenomena as the emergent by-product of human interactions. Blockchains are a digital technology combining peer-to-peer network computing and cryptography to create an immutable decentralised public ledger. The blockchain contrasts vintage ledger technologies, either paper-based or maintained by in-house databases, largely reliant upon hierarchical, third-party trust mechanisms for their maintenance and security. Recent contributions to the blockchain studies literature suggest that the blockchain itself poses as an institutional technology that could challenge existing forms of coordination and governance organised on the basis of vintage ledgers. This proposition has significant implications for the relevance of existing entangled relationships in the economic, social and political domains. Blockchain enables non-territorial 'crypto-secession', not only reducing the costs associated with maintaining ledgers, but radically revising and deconcentrating data-conditioned networks to fundamentally challenge the economic positions of legacy firms and governments. These insights are further illuminated with reference to finance, property and identity cases. Entangled political economy provides a compelling lens through which we can discern the impact of blockchain technology on some of our most important relationships.


Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2096
Author(s):  
Rakib Ul Haque ◽  
A S M Touhidul Hasan ◽  
Qingshan Jiang ◽  
Qiang Qu

Numerous works focus on the data privacy issue of the Internet of Things (IoT) when training a supervised Machine Learning (ML) classifier. Most of the existing solutions assume that the classifier’s training data can be obtained securely from different IoT data providers. The primary concern is data privacy when training a K-Nearest Neighbour (K-NN) classifier with IoT data from various entities. This paper proposes secure K-NN, which provides a privacy-preserving K-NN training over IoT data. It employs Blockchain technology with a partial homomorphic cryptosystem (PHC) known as Paillier in order to protect all participants (i.e., IoT data analyst C and IoT data provider P) data privacy. When C analyzes the IoT data of P, both participants’ privacy issue arises and requires a trusted third party. To protect each candidate’s privacy and remove the dependency on a third-party, we assemble secure building blocks in secure K-NN based on Blockchain technology. Firstly, a protected data-sharing platform is developed among various P, where encrypted IoT data is registered on a shared ledger. Secondly, the secure polynomial operation (SPO), secure biasing operations (SBO), and secure comparison (SC) are designed using the homomorphic property of Paillier. It shows that secure K-NN does not need any trusted third-party at the time of interaction, and rigorous security analysis demonstrates that secure K-NN protects sensitive data privacy for each P and C. The secure K-NN achieved 97.84%, 82.33%, and 76.33% precisions on BCWD, HDD, and DD datasets. The performance of secure K-NN is precisely similar to the general K-NN and outperforms all the previous state of art methods.


Author(s):  
Andreas Bolfing

Chapter 10 deals with the fact that quantum computers will break all current practical digital signature schemes once large-scale quantum computers become reality. The chapter starts with an outline of the major cryptographic primitives that are considered to be quantum-safe and compare their efficiency and usability for blockchain networks. For this, it compares the basic factors of the most popular classical public-key schemes and some chosen post-quantum approaches. This is followed by an introduction to hash-based cryptosystems. Based on Lamport-Diffie one-time signatures, it shows how hash-based signature schemes work and how they can be transformed to multi-signature schemes.


2020 ◽  
Vol 1 (1) ◽  
pp. 4-18
Author(s):  
Danda B. Rawat ◽  
Vijay Chaudhary ◽  
Ronald Doku

Blockchain, also known as a distributed ledger technology, stores different transactions/operations in a chain of blocks in a distributed manner without needing a trusted third-party. Blockchain is proven to be immutable, which helps with integrity and accountability, and, to some extent, confidentiality through a pair of public and private keys. Blockchain has been in the spotlight after successful boom of the Bitcoin. There have been efforts to leverage salient features of Blockchain for different applications and use cases. This paper presents a comprehensive survey of applications and use cases of Blockchain technology for making smart systems secure and trustworthy. Specifically, readers of this paper can have thorough understanding of applications and use cases of Blockchain technology.


2019 ◽  
Vol 5 (1) ◽  
pp. 15-22
Author(s):  
Ardian Thresnantia Atmaja

The key objectives of this paper is to propose a design implementation of blockchain based on smart contract which have potential to change international mobile roaming business model by eliminating third-party data clearing house (DCH). The analysis method used comparative analysis between current situation and target architecture of international mobile roaming business that commonly used by TOGAF Architecture Development Method. The purposed design of implementation has validated the business value by using Total Cost of Ownership (TCO) calculation. This paper applies the TOGAF approach in order to address architecture gap to evaluate by the enhancement capability that required from these three fundamental aspect which are Business, Technology and Information. With the blockchain smart contract solution able to eliminate the intermediaries Data Clearing House system, which impacted to the business model of international mobile roaming with no more intermediaries fee for call data record (CDR) processing and open up for online billing and settlement among parties. In conclusion the business value of blockchain implementation in the international mobile roaming has been measured using TCO comparison between current situation and target architecture that impacted cost reduction of operational platform is 19%. With this information and understanding the blockchain technology has significant benefit in the international mobile roaming business.


Author(s):  
Lily N Edwards-Callaway ◽  
M Caitlin Cramer ◽  
Caitlin N Cadaret ◽  
Elizabeth J Bigler ◽  
Terry E Engle ◽  
...  

ABSTRACT Shade is a mechanism to reduce heat load providing cattle with an environment supportive of their welfare needs. Although heat stress has been extensively reviewed, researched, and addressed in dairy production systems, it has not been investigated in the same manner in the beef cattle supply chain. Like all animals, beef cattle are susceptible to heat stress if they are unable to dissipate heat during times of elevated ambient temperatures. There are many factors that impact heat stress susceptibility in beef cattle throughout the different supply chain sectors, many of which relate to the production system, i.e. availability of shade, microclimate of environment, and nutrition management. The results from studies evaluating the effects of shade on production and welfare are difficult to compare due to variation in structural design, construction materials used, height, shape, and area of shade provided. Additionally, depending on operation location, shade may or may not be beneficial during all times of the year, which can influence the decision to make shade a permanent part of management systems. Shade has been shown to lessen the physiologic response of cattle to heat stress. Shaded cattle exhibit lower respiration rates, body temperatures, and panting scores compared to un-shaded cattle in weather that increases the risk of heat stress. Results from studies investigating the provision of shade indicate that cattle seek shade in hot weather. The impact of shade on behavioral patterns is inconsistent in the current body of research, some studies indicating shade provision impacts behavior and other studies reporting no difference between shaded and un-shaded groups. Analysis of performance and carcass characteristics across feedlot studies demonstrated that shaded cattle had increased ADG, improved feed efficiency, HCW, and dressing percentage when compared to cattle without shade. Despite the documented benefits of shade, current industry statistics, although severely limited in scope, indicate low shade implementation rates in feedlots and data in other supply chain sectors do not exist. Industry guidelines and third party on-farm certification programs articulate the critical need for protection from extreme weather but are not consistent in providing specific recommendations and requirements. Future efforts should include: updated economic analyses of cost versus benefit of shade implementation, exploration of producer perspectives and needs relative to shade, consideration of shade impacts in the cow-calf and slaughter plant segments of the supply chain, and integration of indicators of affective (mental) state and preference in research studies to enhance the holistic assessment of cattle welfare.


2021 ◽  
Vol 11 (9) ◽  
pp. 4011
Author(s):  
Dan Wang ◽  
Jindong Zhao ◽  
Chunxiao Mu

In the field of modern bidding, electronic bidding leads a new trend of development, convenience and efficiency and other significant advantages effectively promote the reform and innovation of China’s bidding field. Nowadays, most systems require a strong and trusted third party to guarantee the integrity and security of the system. However, with the development of blockchain technology and the rise of privacy protection, researchers has begun to emphasize the core concept of decentralization. This paper introduces a decentralized electronic bidding system based on blockchain and smart contract. The system uses blockchain to replace the traditional database and uses chaincode to process business logic. In data interaction, encryption techniques such as zero-knowledge proof based on graph isomorphism are used to improve privacy protection, which improves the anonymity of participants, the privacy of data transmission, and the traceability and verifiable of data. Compared with other electronic bidding systems, this system is more secure and efficient, and has the nature of anonymous operation, which fully protects the privacy information in the bidding process.


Sign in / Sign up

Export Citation Format

Share Document