An Overview on Blockchain

IRJET, 2022

Blockchains are distributed (i.e., without a central repository) and typically decentralized (i.e., not controlled by a bank, enterprise, or government) tamperevident and tamper-resistant digital ledgers. At their most basic level, they allow a group of users to log transactions in a shared ledger such that, as long as the blockchain network is functioning normally, no transaction can be modified once it has been recorded. An exhaustive summary of blockchain technology is presented in this article.

International Journal of Engineering and Computer Science

Blockchain is defined as a group of unsegregated blocks over a P2P network. It is also considered as a decentralised ledger which holds the records of any online event. It offers a secure platform for knowledge and value transfer even in an untrustworthy network. In digital transactions on blockchain, each transaction is verified by all the nodes within the network using consensus protocol. Through this paper we will give a comprehensive overview of how Blockchain technology works, its current and future applications and how it can change the digital events in future.

International Journal of Healthcare Information Systems and Informatics

Many applications are being built using the immutability and robustness of blockchain. Blockchain is a new class of information technology that combines cryptography and a distributed ledger that already exists. The model is composed of a group of computers that collaborate towards maintaining a secured database without storing the data at any central unit. It is the technology behind all the crypto currencies like Bitcoin, Litecoin, Ethereum, and now finding its way to record everything possible. This paper focuses on the basic framework of blockchain model, its pre-requisites, and challenges of blockchain. Various current real-time applications of the technology are also discussed. Finally, an application area has been proposed that can be used to create a huge database of the citizens of the country and facilitate them with ease of access to their personal data. It will open new ways of data analysis at a nationwide scale.

Blockchain, the technology behind most cryptocurrencies that exist today, offers a paradigm shifting technology that has the potential to transform the way that we record and verify events on the Internet. By offering a decentralized, immutable, community verified record of transactions, regardless of what these transactions represent, blockchain technology promises to transform many industries. In this paper, we provide a survey of this very important technology and discuss its possible use-cases and its effect on society. The purpose of this paper is to familiarize the reader with the current state-of-the-art in the blockchain world both in terms of technology and social impact.

2015

This paper is intended to enlighten curious minds, breakdown and explain what Bitcoin really is in the simplest ways possible. First I will introduce and define what Bitcoin really is and explain the Block Chain technology, give a simple comparison with the internet and why Block Chain will keep thriving, key features of the Block Chain, describe potential systems where the Block Chain technology could be utilised for improvement and finally the conclusion. Introduction: In 2008 October 31 when Satoshi Nakamoto released the Bitcoin white paper[1], he/she/they did not cater for the non engineers and mathematicians. Even though a good general description of what Bitcoin is meant to be and how it works was clearly explained. In most cases becaue of it's initial implementation in the finance sector, it has been known as "computer money" or "nerd money." Bitcoin simply broken down is Bit-Coin, "Bit"[2] being the smallest unit of data in a computer which is also short for binary digit. A bit has a single binary value of either 1 or 0. While "Coin"[3] could be defined as money or unit that holds value. Now we know why Satoshi Nakamoto chose the name "Bitcoin." Though Bitcoin is the network on which the Block Chain protocol is built on top of. The BlockChain: Block Chain is the technology protocol that Bitcoin is built ontop of. Just like the internet that was introduced in the 1960s and late 1970s, is a communications protocol that governs the rules and regulations for information exchange over the network of networks, Block Chain is a protocol that governs the rules and regulations for value exchange. One is the internet of information, while the other is the internet of value. Internet is a communications protocol and Block Chain is value exchange protocol. With "value " [4] being broadly defined. The same reasons that made and still make the internet a success, are the same ones that will make the Block Chain thrive. For example its fast, public, open to anyone, cheap and easy to utilize, transparent and programmable. Just like how the internet made it possible to transfer information instateniously from any part of the world, the Block Chain technology let's the users transfer value globally. Block Chain features: Fast: Communication between peers on the network is fast and in places where time is a vital factor for operations and trade, this feature comes in handy. Cheap: Using the Block Chain for reasons of payment and value exchange, is cheaper than any other system in place at the moment. Easyly Accesible & Public: Any one from all over the world can utilise the Block Chain technology via a Bitcoin client such as Amory, Bitcoin core, bitcoind and many more. Open Source & Programmable: It can be programmed to meet a particular need. For instance the need to have a finacial payment system (micro payments) and it can be programmed by anyone with software evelopment skills to meet a particular need. Transparent: These are the most brilliant features of the Block Chain, it's transparency makes it available for anyone on the network to view. Something like a legder accessible by everyone, like a "universal consesus"[5] so to say. Not only is it visible by every one, it is also time stamped. Distributed: The fact that the Block Chain utilises a distributed network, this makes it more secure than any other centralised institution like finanncial banks and the rest a like. This is because vital data likecryptographic keys used for online financial payments and trade are not kept in the same place. In case an attacker was to compromise the Block Chain, chases are very slim that he could have a successful attack.

International Journal of Innovative Computing

Blockchain, Bitcoin's core technology, and spinal cord have received enthusiastic attention since the last couple of decades. The Blockchain serves as a paradigm for distributed and unchangeable computations for bitcoins and cryptocurrencies. The key features behind this technology are to create a reliable, secure, transparent, decentralized, and reliable autonomous ecosystem. It is useful for a variety of applications, especially for legacy devices, resources, and infrastructure. In this article, we presented a technical overview, its application, and the challenges associated with blockchain technology and cryptocurrencies. This study aims to provide a ground-breaking overview and future research direction and promising importance of Blockchain.

International Journal for Research in Applied Science and Engineering Technology IJRASET, 2020

Blockchain technology is the key for decentralized society and gathered a lot of attention in recent times. The technology of Blockchain offers an infrastructure of secure network that allows the users to perform any operation without middleman. It is expected to bring a revolution due to its characteristics of being transparent, secure and scalable. Blockchain technology will bring the considerable efficiency gains, transparency, cost savings and fraud detection while allowing the data to be shared in real-time between multiple parties in a trusted and transparent manner. This chapter elaborately discusses the basic building blocks of Blockchain technology such as public key cryptography, Digital signature, Elements and types of Blockchain and its applications in different sectors. I. INTRODUCTION Blockchain is a chain of blocks in which the information of transactions is recorded and maintained in a distributed public ledger across a number of computers that are linked in a peer-to-peer network. Blockchain was first introduced by [1] who proposed a peer-to-peer payment system that allows cash transactions through the Internet without relying on the need for a financial institution. Blockchain is secure by design, and an example of a system with a high byzantine failure tolerance [2]. Bitcoin is the first application of the Blockchain concept to create a currency that could be exchanged over the internet using cryptography to secure the transactions. Bitcoin blockchain is the mother of all blockchain. Blockchain is an ordered data structure that contains blocks of transactions. Each block in the blockchain is linked to the previous block in the chain. The first block in the chain is referred to as the Genesis block. Each block created gets layered on top of the previous block to form a stack called a Blockchain. There are a set of rules for confirmation of the legitimacy of a block and to verify that block has not been altered maliciously. Blockchain technology solved the problem of Double-spending (the event where customer can spend a set of the same bitcoins in two different transactions) as the second transaction would be recognized as invalid.

2021

A blockchain is a decentralized distributed public and digital ledger consisting of blocks that record transactions across many systems, ensuring security as these blocks cannot be altered retroactively. This technology enables individuals and companies to participate with trust and transparency. A well-known application of blockchain is the cryptographic currencies Bitcoin, an emerging technology like Ethereum and many more applications are possible. Blockchain, with great potential, allows us to create, value, trust, truthfully by clever use of distributed ledger, cryptography, and computation. It emphasizes the potential of a decentralized world, where users of technology can be empowered without being bound by a third-party power broker and many other benefits this technology presents to us. Blockchain technology is the driving force behind the next basic change in information technology. Many uses of blockchain technology are widely available today, each with the potential of a specific application domain. A blockchain is a diary that is almost impossible to forge. Blockchain technology is an interesting and a safe alternative for people, using this does not demand you to have a technical background, it will somehow have a positive effect on citizens. It will prove to be a better financial system and excites us to make blockchain more mainstream. Here, we have provided a brief survey on blockchain technology and how it is establishing itself to make an impact on the future of technology.

2017

The blockchain is generally defined as publicly disclosed and linked ledger of online transactions that are performed in peer to peer network. Also, all the transactions executed in this public ledger are verified by the majority of the participants. Blockchain has brought a different approach to the data sharing and management. It has come up with the solutions to a number of problems that the digital world has been facing since long. Blockchain technology is highly efficient to transform a number of industries such as financial and non-financial ones.

American Journal of Management

Blockchain is the Technology which allows assets to be transferred from one party to another simultaneously and without needing a third party, guaranteeing utmost security. In addition, it is a multiple global ledgers, shared by all people around the world, which enables them to do all kinds of transactions (Sutardja Center for Entrepreneurship & Technology Technical Report, 2015) in real time and without falling prey to fraud or manipulation. Besides, it is the biggest data bases, accessible to all people (BigchainDB, 2016) and containing verified assets which can be safely exchanged. Blockchain will have a huge effect on deferent levels, it will change the way all people adopt to deal through decades and threat traditional intermediary parties, on the other side it faces many obstacles stumbling blocks to be fully operated in different fields. This paper try to address the mechanism of blockchain technology, and how it works in simple words, then determine the possible applications of blockchain, and how to make best use of this technology, and finally the threats and challenges of blockchain. WHY BLOCKCHAIN IS A REVOLUTION? The blockchain system was first used in 2008 as the main platform for Bitcoin's virtual currency. Thanks to Blockchain, this cryptocurrency has won users' trust, so far at least. It is a common misconception that Bitcoin and Blockchain are one and the same; the truth is that the latter can be regarded as the backbone of the former, which distinguishes it from other digital currency systems (KAYE Scholar, 2018). It is worth mentioning that the Blockchain system can be used in many other applications. Traditional transactions and asset transfer usually involve mediators. These can be banks, necessary for money transfer, a ministry entitled to register transactions, a real estate publicity department to verify ownership, a real estate broker, etc. These intermediary entities are usually paid for their services. Blockchain provides an alternative where files are transferred, stored and managed with no need for such mediators. To be more accurate, the real mediator in this case would be millions of computers connected to the chain. The transaction moves from one computer to another in an encrypted form that guarantees safety, rules out the possibility of manipulation, forgery or fraud and secures registration priority rights. This poses a threat to millions of people around the world who would be more than likely to lose their jobs because of this system.