In order to successfully hack a Proof of Work blockchain network, the hacker would need to take control of at least 51% of the peer-to-peer network’s power to add new data (hashing). This is called a 51% attack. In a Proof of Stake network, the hacker would need to own 51% of the blockchains cryptocurrency.

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In 2018, Bitcoin Gold (BTG) experienced a 51% attack leading to more than $18M in losses.

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