And? What actual problem does this solve or realistic threat does this prevent? They are not decryption keys they are used to digitally sign certificates.

What the DigiNotar hack taught us years ago is if your CA is compromised you are already 0wned doesn't matter if the key is stored in an HSM or not.

All they can do with a stolen key is issue more certificates. Which they can do anyway if they have root access to the CA.

You can put 12 locks on your door but if they're all keyed to the same key you've stored under the plant on the porch, it doesn't really matter.

> The interesting thing about this article is that it adds a few 9's that are covered, and it's both easy and cheap.

Hard to say if those extra 9's need an external RNG for extra entropy.