I think it will simply become impossible to keep digital payment systems secure. The whole online economy will collapse. Amazon will become worthless. People will actually have to go out to local stores to buy everything. People will have to go to their local bank or currency exchange to cash their paychecks. The credit card system will fail completely too, while payday loans will take their place. The stock market will have to go back to traders yelling their trades to each other at exchanges. The old ways will become new.
I havent heard of any AI research effort similar to the Navier-Stokes breakthrough to break elliptical curve cryptography but wouldn’t be surprised if such a thing happened. I mean, I’m sure I’d be surprised as the global banking system collapsed many times but a research effort like that seems reasonable to assume would be desirable by some state or private actor.