Abstract:
Blockcahin is such a technology that helps us to use a shared ledger. Although the ledger
is in shared manner, the total system is quiet secure. Bitcoin is a crypto currency which
uses blochchain technology. Value of Blockchain is very high than doller or some other
expensive currency. This is one of the reasons of encouraging theft attack on the
blockchain technology. In this paper, we analyze about the attacks of blockchain, their
targeted area, reason and their possible solution. In this paper our main focus was to
represent a total review on Blockchain technology. Besides this, Double spending attack is
a major attack on blockchain which is occurred twice till now and causes a huge loss of
crypto currency. In this paper, we also try to find out the reason of this attack and we have
proposed one solution that can prevent Double Spending Attack. Our findings will provide
some future direction for initial research and also help the crypto business analysts to
predict about present security in the aspects of blockchain network.