What is proof of work?

Proof of work solves a hard problem: how does a network with no central authority agree on what happened, when anyone can join anonymously? The answer is to make proposing blocks costly. Participants must find a solution to a computational puzzle, which takes electricity and specialised hardware.

Because the cost is real and external, an attacker cannot simply create more identities. To rewrite history they would need to out-compute the honest majority, sustained over time — which on a large network costs more than any plausible gain.

The criticism is straightforward: this consumes a great deal of energy by design, since the security comes from the expenditure itself. Defenders argue that the energy buys a genuinely neutral settlement network and increasingly comes from otherwise-stranded generation. It remains a live and legitimate debate.