Kevin, Would something like this suffice or at least lead you in the direction you were headed? http://www.codeproject.com/KB/security/steganodotnet8.aspx -M Date: Sun, 23 Oct 2011 08:13:24 -0700 From: Kevin Cosgrove <kevinc(a)cosgroves.us> Subject: [LAU] Looking for Audio Watermarking Advice & Tools To: linux-audio-user(a)lists.linuxaudio.org Message-ID: <20111023151325.350C7BE006(a)joseph.cosgroves.us> Content-Type: text/plain; charset=us-ascii The subject line says it all.  I'm looking for a Linux solution to watermarking audio.  Thanks.... -- Kevinersion 0.01 even just being able to attach an md5 sum of an  audio file along with a gpg signature would be cool. I use a subset of GNUPG's capability.  Maybe you can see that in my above requirements?  ;-) Is that a useful start on a start? Thanks.... -- Kevin