It's definitely proof of work (ethash), although the plan is to transition to proof of stake in the future. Their most recent blog entry on this: https://blog.

It's definitely proof of work (ethash), although the plan is to transition to proof of stake in the future. Their most recent blog entry on this: https://blog.ethereum.org/2015/08/01/introducing-casper-friendly-ghost/ https://blog.ethereum.org/2015/08/01/introducing-casper-frie...