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by mjburgess 868 days ago
if you split the network, you can add your own machines, that can rewrite the history arbitrarily from the future of that split.

As for "a few minutes", it depends on which one we're talking about. BTC, yes -- but disrupting the global BTC network requires only a few minutes of time. Just dump everything into unusable addresses, and watch the reaction.
1 comments
rlpb 868 days ago
> can rewrite the history arbitrarily

No, you cannot do that. Transactions would still need to be signed by the corresponding owners. All you could do is reorder (and thus invalidate) some transactions, drop some transactions, or add some that weren't originally included.

> Just dump everything into unusable addresses...

Nope; that's not possible. You wouldn't have the signatures to do that even with 51% hashing power.

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mjburgess 868 days ago
You're right about the dumping; I was thinking more about the case where you controlled the protocol on the machines of a partitioned network (eg., so you release a new version of btc which uses exploitable crytography, etc.).

In the case of a mere 51% at scale, hijinks are still quite possible from replays, reorderings, etc.

I was more preoccupied by the case where the state's acting in its own borders with control over the network, major miners, most machines on the network -- at this point basically no gaurentees remain

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rlpb 867 days ago
> the case where you controlled the protocol on the machines of a partitioned network (eg., so you release a new version of btc which uses exploitable crytography

Such a change would be treated as a "monopoly money" fork by those wanting to transact, and ignored. "No I don't want your fake money; send me real BTC or GTFO". This is why miners cannot arbitrarily change the protocol in their favour even today.

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