A decentralised peer-to-peer technology called blockchain offers security services based on the following four core ideas: authentication, confidentiality, integrity, and authorisation. The purpose of this paper is to provide an overview of the blockchain's mechanism, architecture, and various components. It also compares different blockchain types based on various parameters and their applicability. This paper also emphasises the general security of blockchain. We evaluate the blockchain in particular to create thorough categories for blockchain security risks, examine actual attacks by bugs against the blockchain, and list recently created security measures for the technology. This paper also demonstrates the significance of various blockchain applications in the fields of healthcare, IoT, smart grid, governance, defence, and military. Overall, this paper provides an overview of various blockchain applications, their characteristics, challenges, and potential future.
Sami HyrynsalmiSonja M. HyrynsalmiKai K. Kimppa
Shruti AgrawalNidhi SharmaMaria Elena BruniGianpaolo Iazzolino
Faiza BashirNosheen Fatima Warraich