Firefox 32 moves to kill MITM attacks

Public key pinning, security fixes, better cache

The Mozilla Foundation has stepped up its efforts to improve browser security with the launch of Firefox 32, adding public key pinning to try and protect users from man-in-the-middle and other attacks.

The change is among a bunch of enhancements offered in the new version, now available for Windows, Mac, Linux and Android users.

Public key pinning is designed to relieve users of some of the burden of keeping track of certificates, since the trusted sites – at the moment addons.mozilla.org and Twitter, with Google to come soon – can instruct the user agent to remember the host's cryptographic identity for a specified amount of time (the IETF spec is here).

Pinning, Mozilla says, improves the security of implementations such as TLS. It “allows site operators to specify which CAs issue valid certificates for them, rather than accepting any one of the hundreds of built-in root certificates that ship with Firefox.