sentences:  On April 16, 2007, the AACS consortium announced that it had revoked the Device Keys used by both Cyberlink PowerDVD and InterVideo WinDVD, and patches were made available for users which provided uncompromised encryption keys and better security for the keys.To continue having the ability to view new content users were forced to apply the patches, which also hardened the security of player applications.On 23 May 2007 the Processing Key for the next version of the Media Key Block was posted to the comments page of a Freedom to Tinker blog post.