It shouldn’t even need much distribution or any protocol change. If every CT operator required three separate nodes to validate a proposed new block before distributing that block, then the only way to corrupt the log would be for an invalid block to pass verification three times (due to a bug or to a vanishingly unlikely coincidence of hardware errors) or for something to accidentally publish the block without verification.

Unlike cryptocurrency, this would require no fancy public protocols, negligible computational resources, and no additional verification overhead outside the log operator at all.