A Survey on Blockchain Technology Concepts, Applications and Security

Abstract

In the past decade, blockchain technology has become increasingly prevalent in our daily lives. This technology consists of a chain of blocks that contains the history of transactions and information about its users. Distributed digital ledgers are used in blockchain. A transparent environment is created by using this technology, allowing encrypted secure transactions to be verified and approved by all users. As a powerful tool, blockchain can be utilized for a wide range of useful purposes in everyday life including cryptocurrency, Internet-of-Things (IoT), finance, reputation system, and healthcare. This paper aims to provide an overview of blockchain technology and its security issues for users and researchers. In particular, those who conduct their business using blockchain technology. This paper includes a comparison of consensus algorithms and a description of cryptography. Further, most applications used in blockchain are focused on in this paper also analyzing real attacks and then summarizing security measures in blockchain. Even though Blockchain holds a promising scope of development in several sectors, it is prone to several security and vulnerability issues that arise from different types of blockchain networks which represent a challenge to deal with blockchain. Finally, as a research community, we encourage future research challenges that can be addressed to improve security in blockchain systems.