What Is a ’51 Percent Attack’ and How Do Consensus Models like PoA Try to Prevent It?

A '51 percent attack' occurs when a single entity or group gains control of more than half of the network's mining hash rate (PoW) or staked coins (PoS). This control allows them to disrupt transaction ordering, reverse recent transactions, and potentially double-spend coins.

PoA prevents this by requiring an attacker to control both the PoW mining power and a majority of the staked coins simultaneously. The hybrid nature significantly increases the cost and complexity of launching a successful attack.