Bitcoin-Blockchain Technology: Security Perspective

Nowadays, Blockchain technology has also drawn mammoth attention as it is currently triggering multiple projects. This technology is the prevalent technology that allows Bitcoin to operate. Bitcoin has already cemented itself as a popular virtual currency, and it will soon become a pressing requirement for citizens. Furthermore, with digital currencies proliferating all over the world, security must not be overlooked, especially when there have been numerous attacks and security vulnerabilities on bitcoin's blockchain. However, the lucrative system has drawn opponents and attackers who are continually attempting to exploit flaws in the technology in order to get profit. This paper contemplates the bitcoin's transaction process, with a focus on obscuring the true identities of clients and their coins prior to transacting, and then elucidating on the following: SHA-256 function, the primary threats to Bitcoin's security, along with some countermeasures to be undertaken.

I. Introduction

The first real-world implementation of blockchain came with the launch of Bitcoin in January 2009 [1]. Blockchain is the most prominent technology; it contains a series of blocks that holds data in blocks and stores it in hash functions with timestamps. These blocks are then cryptographically linked together to ensure data integrity that cannot be altered or tampered. Stuart Haber and W. Scott Stornetta, two researchers, invented blockchain technology in 1991 to build a system where document timestamps could not be tampered [2]. Bitcoin is a peer-to-peer file-sharing protocol that employs the SHA-256 algorithm. It was developed with two main purposes: to create a digital currency and to make financial transactions. In this network, each participant has their own address, which acts as a public key with its own record of all transactions [3]. It creates a decentralized cryptocurrency environment where users may buy and sell goods with digital currency. It is still the most widely utilized Blockchain application today [4]. From 2013 to 2017, the public is now becoming aware of bitcoin's existence. The market value of Bitcoin has soared from roughly one billion dollars in 2013 to several times that amount since its spectacular ascent in popularity in 2017. In the first quarter of 2021, the Bitcoin market capitalization rose at its peak and grew by over $1,000 billion. Since then, the market capitalization has fallen, reaching around$600 billion in June 2021[5]. Figure 1 shows a graph of Bitcoin's market capitalization from April 2013 to March 10, 2022.