I think it technically was not “brute forcing” (since it wasn’t found by searching the entire key space), but specifically someone tried generating CA cert private keys from numbers 0-255, and surprisingly found a few.
We don’t know whether anyone tried it before April 2025, because that’s when the vulnerable certificates were issued. If someone did try it before then, they would not find any certificates (as expected) and probably wouldn’t even talk to anyone about it.
It feels like the kind if thing that someone, somewhere would have a script running constantly testing for private keys with low values. That it went 18 months without being found is a miracle!
I think there’s a good chance people will be looking for this now so will get caught a lot quicker next time.
I think there’s a good chance people will be looking for this now so will get caught a lot quicker next time.
That’s pretty much guaranteed from now on, yes.
It feels like the kind if thing that someone, somewhere would have a script running constantly testing for private keys with low values. That it went 18 months without being found is a miracle!
It’s not the kind of thing you’d expect to need to guard against, or even really think of. It should not happen. It sounds like someone was kind of just fooling around with making private keys and stumbled upon it.
I guess now someone needs to try seeding some of the most popular PRNGs with 0-255 and seeing whether any keys come up in the first few hundred numbers.
I think it technically was not “brute forcing” (since it wasn’t found by searching the entire key space), but specifically someone tried generating CA cert private keys from numbers 0-255, and surprisingly found a few.
So why did it take so long for someone to try it?
Kind of like how you don’t expect to walk up to an atm, press 1234, and hope for a million dollars to spit out.
We don’t know whether anyone tried it before April 2025, because that’s when the vulnerable certificates were issued. If someone did try it before then, they would not find any certificates (as expected) and probably wouldn’t even talk to anyone about it.
It feels like the kind if thing that someone, somewhere would have a script running constantly testing for private keys with low values. That it went 18 months without being found is a miracle!
I think there’s a good chance people will be looking for this now so will get caught a lot quicker next time.
That’s pretty much guaranteed from now on, yes.
It’s not the kind of thing you’d expect to need to guard against, or even really think of. It should not happen. It sounds like someone was kind of just fooling around with making private keys and stumbled upon it.
I guess now someone needs to try seeding some of the most popular PRNGs with 0-255 and seeing whether any keys come up in the first few hundred numbers.