We don't know exactly the design of a rig that would solve a 1024-bit discrete log or factoring problem, but we have a decent idea of what it would probably cost, and most VC firms could fund it.
Costs don't scale linearly. No math projection puts 2048 bit keys in reach. The thing that breaks 2048 bit RSA may well put RSA completely out of action, a reason to prefer alternatives to RSA over 4096-bit keys.
Granted, but if that's the concern, that's what the article ought to be explaining:
We are aware of the infrastructure to break 1024-bit discrete logs, and it's feasible; current projections put 2048 bit key safely out of reach for the time being, so we'll disable 1024 and leave 2048 enabled.
My concern there is with the talk of 'unknown attacks' and then providing suggestions based on that statement.
> but we have a decent idea of what it would probably cost, and most VC firms could fund it.
I'd wonder if a "CaaS" startup (Cracking as a service) would be feasible. Using amazon spot instances, it would require only as much funding as to serve the first ten users - and requiring each user to send the money to an escrow, e.g. a notary (in Germany, it's possible to deposit an amount at a notary, which gives the customer the assurance that without the private key, the company gets their money and the company has the assurance that the customer doesn't walk away with the keys and leaves the company with a 5-figure AWS bill).
Costs don't scale linearly. No math projection puts 2048 bit keys in reach. The thing that breaks 2048 bit RSA may well put RSA completely out of action, a reason to prefer alternatives to RSA over 4096-bit keys.