I'm new to SSL/TSL and was wondering if you could walk me through the following scenario.
Let's say I am one of a thousand websites that has a certificate signed by some certificate authority (CA).
Everything is fine.
Then, some evil hacker steals the CA's private key. Now, all of a sudden, all thousand website's certificates are untrustworthy because the hacker can issue certificates signed with the stolen private key and one can't distinguish between real and fake certificates anymore.
The CA revokes his stolen certificate, so I end up with a website that no browser recognizes as trustworthy anymore.
What do I do now? I've read these questions:
- What can an attacker do with a stolen SSL private key? What should the web admin do?.
- What happens when an Intermediate CA is revoked?
Now, I got to run and get a new certificate signed by a still trusted CA.
Therefore, I was wondering: what should I have done in advance so that once the CA's private key is stolen, I don't have to run, but can lean back and don't have to worry about it?
Should I have a second certificate ready which was signed by another CA which I can deploy once the other one gets untrustworthy?
Can my old certificate be simultaneously signed by a second CA so that it stays valid even if one CA's private key is compromised?
What mitigation scenarios are there?
The question came up after reading these cases: