[cap-talk] Compelled Certificate Creation Attack on SSL

[Sandro Magi]

This will probably come as no surprise to most of you given past
discussions of the SSL Certificate Authority (CA) model, but this new
paper highlights quite clearly the trust problems inherent to CAs:

  http://files.cloudprivacy.net/ssl-mitm.pdf

It basically describes a "compelled certificate creation attack", where
a government can compel a CA to issue a valid certificate that can be
used for surveillance. Note, this means foreign governments could be
spying on you too, not just your own government.

He also describes appliances that are being sold explicitly for this
purpose, implying that compelled certificates may already be in use.

He also provides a Firefox plugin prevent this attack called Certlock,
which basically caches the certificate hash and the CA's country on
first load. If on subsequent page loads the hash and the country
differs, an error is displayed.

I had commented on an earlier draft and pointed him to the Petname tool,
which is now mentioned in the section Related Work. The Petname tool and
TrustBar both handle this attack and are both strictly more general than
the approach presented in this paper.

Sandro