Blockchain: Ultimate guide to understanding blockchain, bitcoin, cryptocurrencies, smart contracts and the future of money. (Ultimate Cryptocurrency Book 1)

by Mark Gates

All computers on the blockchain network have a copy of the blockchain, reducing the risk of data loss. To manipulate the data on a blockchain requires “hacking” over 50% of the computers on the network at the same time, which is almost completely unfeasible.

Why it is hard and secure but still not full proof.