Blockchain has swiftly become one of the most dominant and promising technologies of the past couple of years. The information security is the key to the development of contemporaneous Internet technology. The distributed mechanism, scripted mechanism, password mechanism and decentralized mechanism of the Blockchain present a perfectly new perspective for the development of Internet information security technology. Blockchain is a distributed database that maintains a successively increasingly list of records called blocks that are secured from any kind of interfere with and revision endeavor. A word that often emerges when talking about Blockchain is Bitcoin. The numerous people still confuse Blockchain with Bitcoinal though, they are not the same. Bitcoin is just one of several applications that use Blockchain technology. In Blockchain every block contains a time stamp and a link to the previous block. Blockchain extant level of security of a system and data perspective for both private and public ledgers. Alternatively, uploading data to a cloud server or storing it in a single location, as well as breaking everything into small chunks and distributes them across the whole network of computers. In this paper, we try to conduct a comprehensive survey on the Blockchain security as well as the challenges and opportunities for the prospective of security and privacy of data in Blockchain. In its present state, several leading companies and governments detect demonstrations of the Blockchain integrated intoidentity management, credential validation, finance, supply chain, property exchange recording, and other territory
