[marltod]

Is the idea that it can be proven that you have a DV product but it cannot be proven that the unit has been recording?

1. If the hard drive is making a lot of noise it is probably recording video.

2. This is security through obscurity. The data is not being encrypted in a standard way. But the binaries on the computer that are used to decrypt the data can be decompiled to discover this obscure method. At that point you have no advantage over other encryption programs.

  If you want to be deniable get rid of the hard drive and require an internet connection.  Then when someone gets your "DV" unit and asks where the video is you can say it was set to live streaming mode and is never recorded.