tamper proofing audio

[Jacob Meuser]

On Tue, Jun 21, 2005 at 10:13:14PM -0700, Jacob Meuser wrote:
> On Wed, Jun 22, 2005 at 02:12:20PM +0930, Tim Aslat wrote:
> > Hi All,
> > 
> > can anyone tell me if it's possible to tamper-proof an audio recording
> > in such a way that it can still be played on a normal audio CD player?
> > 
> > I'm not worried about the recording being copied, but I am worried
> > about it being modified and want to guard against it.  Its for a voice
> > recorder project in a lawyers office where they want to be able to
> > prove conclusively that a certain audio recording was made on a
> > specific machine and hasn't been tampered with.  I understand that it
> > is impossible to make anything completely tamper-proof, but I would
> > like to make it at least difficult for someone to do without some very
> > substantial resources and skills available to them.
> 
> Simply verifying the files with checksums (multiple algorithms to
> lessen the possibility of "collision attacks") is insufficient?

also, bsdav -> http://www.jakemsr.com/bsdav/ (which can be used
for audio only) records the system time for every data "frame".
may be useful as well.

-- 
<jakemsr at jakemsr.com>