As Bitcoin Halving Approaches, 51% Attack Question Resurfaces

Many supporters have come to see bitcoin as a model of the perfectly secured digital good.
This view owes itself in no large part to the blockchain, the distributed database that secures units of the digital currency by allowing miners to add and verify transactions without a third party. But, as has long been detailed by academics, the balance of incentives that keeps the blockchain in operation is ever at risk of disruption.
Perhaps the most infamous potential attack, known as a ‘51% attack‘, would find a single entity introducing a version of the blockchain that it controls and is accepted as valid. While academics have argued attacks can be carried out with a smaller percentage of the network, at 51% of the hashrate, such an attack would be almost guaranteed to work.

This post was published at Coin Desk on July 6, 2016.