10.4 Rogue CAs
If a CA is compromised, it will issue certificates for web servers with a fake identity, and impersonation attacks are the consequence, breaking entity authentication within TLS. The most serious incident of this kind goes by the name of Operation Black Tulip: In July 2011, an attacker took control of the Dutch CA DigiNotar (for more details, see Section 19.5.2 in Chapter 19, Attacks on Cryptography) and issued fraudulent certificates for *.google.com and other important domains [199].
The main target of the attack seemed to be 300,000 Iranian Gmail users, who lost their credentials for various Google services, including Google Mail and Google Docs due to the attack. The real source of the attack was never disclosed. Initially, many signs pointed toward the Iranian government, but later on, the well-known security researcher Bruce Schneier also blamed the NSA [41].
How should we deal with a rogue CA, especially the certificates issued by it? Of course...