Well one, if they crack it and start draining utxos left and right, wouldn't that just nullify the entire experiment? Bitcoin would plummet, the miners would leave the market, the whole house would come down nullifying the benefit of employing that solution. So the motivation only rests in the hands of malicious actors-state and bankers.
So you're saying a single solution could drain every utxo mathematically, no matter how many signatures the wallet has?
Wouldn't that entail cracking the entire time chain? We're talking orders of magnitude more difficult right? Like hundreds of thousands, or millions of digits since every transaction adds complexity.
If so, wouldn't that mean the number changes every 10 minutes? Someone would have to come up with the exact theorem (I think that's what we're saying, otherwise just the right prime number) at exactly the right block to use it. And then sweep everything they could before the next block.