Security on Blockchain Technology

Block chain (BC) is a relatively new technology; which has attracted much attention recently. It has been developed rapidly and can be used in many applications of various domains such as decentralized approaches. Indeed, many companies, even worldwide governments, are now using BC technology to improve the security, scalability, and efficiency of their services. In this paper, we provide an overview of BC security. We start with the basics of BC technology. Next, we give the primary BC security attacks. Finally, we present the BC countermeasures.