Ethereum uses a Proof of Work (PoW) algorithm, which is the most common algorithm used by cryptocurrency systems. PoW works by requiring miners to solve complex mathematical problems in order to add blocks to the blockchain.
The Ethereum network is designed to be resistant to ASIC mining, which means that it is difficult for specialized hardware to be used to mine Ethereum. This is done in order to keep the network decentralized and ensure that it is accessible to as many people as possible.
The PoW algorithm has been proven to be effective at securing networks and preventing 51% attacks. However, it is not without its drawbacks.
One of the main criticisms of PoW is that it is energy intensive, as miners need to use a lot of power in order to solve the complex mathematical problems required to add blocks to the blockchain. Ethereum’s developers are currently working on a new algorithm called Proof of Stake (PoS), which is designed to be more energy efficient than PoW.
So, which algorithm does Ethereum use? At present, it uses a Proof of Work algorithm, but this is likely to change in the future as the network moves towards Proof of Stake.