Last week, security researcher Chris Soghoian blogged about a device from Packet Forensics that seems to be designed to serve as an interceptor of SSL traffic. By installing the device between the client and the server, attackers are able to eavesdrop on traffic from the browser to the Web server even though SSL is in use. The client would see a certificate warning from the browser if the device was configured with a self-generated certificate.
There has been speculation that an organization with sufficient power would be able to get a valid certificate from one of the 170+ certificate authorities (CAs) that are installed by default in the typical browser and could then avoid this alert. The certificate authorities come from many countries and are included in standard browsers to make the encryption process as transparent as possible for all of the potential users of the browser.
But how many CAs does the average Internet user actually need? Fourteen!
Let me explain. For the past two weeks I have been using Firefox on Windows with a reduced set of CAs. I disabled ALL of them in the browser and re-enabled them one by one as necessary during my normal usage. On the first day I re-enabled eight CAs, which took me through the next three days of use; on day four I added three more, and over the next week the rest of them.
This is too painful to recommend to the average user. Browser vendors need to step up and provide the tools and guidance to manage trust in CAs.
-- As the CTO for Qualys, Wolfgang Kandek is responsible for product direction and all operational aspects of the QualysGuard platform and its infrastructure. Wolfgang has more than 20 years of experience in developing and managing information systems. His focus has been on Unix-based server architectures and application delivery through the Internet. Wolfgang provides the latest commentary on his blog: laws.qualys.com and also publishes his Patch Tuesday commentary to the QualysGuard channel: www.youtube.com/QualysGuard. He is a frequent source in business and trade media and speaks at industry conferences around the world, most recently at RSA 2010.