How a Google Headhunter’s E-Mail Unraveled a Massive Net Security Hole

The fix is an easy one – companies simply need to generate a new key at the stronger length and place it in their DNS records. But they also need to remember to revoke their old key, Harris says.

"As long as the old one is still in the DNS record, even if you’re not using it, an attacker can still use it," he says.

Full Story: http://www.wired.com/threatlevel/2012/10/dkim-vulnerability-widespread/

(Many thanks to Chelsea Volkerts at http://www.Hulu.com for sharing this.)