Anything that can rewrite all physical evidence down to the microscopic level can almost certainly conduct a 51% (or a 99.999%) attack against a public ledger against mere mortal hashing boxes. More to the point, it can just physically rewrite every record of such a ledger with one of its own choosing. Computer hardware is physical, after all.
A counter example scenario where this point doesn’t hold true is if the “good” guys have fled to space, and the “evil” AI has physical control of earth’s surface, where all the history is. The center of Bitcoin as determined by light speed delays could shift to a near-solar orbit where there is cheap energy. There could be jurisdictional issues (a peace treaty?) preventing the AI from physically altering ships in space, say, but no such rule prevents plausibly deniable attacks on the ships’ information storage systems.
A 51% blockchain attack doesn’t prevent timestamping from being a credible piece of evidence. There is still a large amount of hash-work piled on top of the timestamp, which would be hard to duplicate. Every alternate history proposed by a deceptive superintelligence would need to meet the same standard of evidence, as long as the hashes in the timestamp haven’t been broken.
Anything that can rewrite all physical evidence down to the microscopic level can almost certainly conduct a 51% (or a 99.999%) attack against a public ledger against mere mortal hashing boxes. More to the point, it can just physically rewrite every record of such a ledger with one of its own choosing. Computer hardware is physical, after all.
A counter example scenario where this point doesn’t hold true is if the “good” guys have fled to space, and the “evil” AI has physical control of earth’s surface, where all the history is. The center of Bitcoin as determined by light speed delays could shift to a near-solar orbit where there is cheap energy. There could be jurisdictional issues (a peace treaty?) preventing the AI from physically altering ships in space, say, but no such rule prevents plausibly deniable attacks on the ships’ information storage systems.
A 51% blockchain attack doesn’t prevent timestamping from being a credible piece of evidence. There is still a large amount of hash-work piled on top of the timestamp, which would be hard to duplicate. Every alternate history proposed by a deceptive superintelligence would need to meet the same standard of evidence, as long as the hashes in the timestamp haven’t been broken.