> These "wrapping" keys were not "weaker". They were completely unfit for purpose.

Oh come on. They clearly didn't intend to use 4 as a private key or to wrap it. They had just purchased millions of dollars of HSM's to store them. It was something more subtle than that.

Have a little imagination. The transfer procedure sounds bespoke - possibly just a shell script using openssl to encrypt things at one end, and decrypt them at the other. Let the man who has written 100 shell scripts without a bug in one cast the first stone.

But not so subtle that good software engineering procedures wouldn't have picked it up. In fact today just an LLM review of the shell script probably would have caught it. The Internet Death Sentence was warranted - because poor software engineering procedures are unforgivable in a CA. But those procedures and policies aren't easy or cheap to come by. If they were just "don't chose 4 as a primary key" my grandkids could do it.