Yes, if you can handle forks as long as you can detect them, centralized consensus is a decent solution with much lower costs that PoW. This is essentially how

Yes, if you can handle forks as long as you can detect them, centralized consensus is a decent solution with much lower costs that PoW. This is essentially how CT-logs work, where we consider it sufficient to detect a falsely-issued certificate, even though we cannot prevent such issuance.