Security quote of the week
Posted Apr 18, 2012 21:44 UTC (Wed) by khim
In reply to: Security quote of the week
Parent article: Security quote of the week
> I think you don't get the full implications of the fact that we are talking about lossy compression here, not about lossless one.
Wrong. Obviously only lossy compression would remove a watermark--lossy compression which encodes the original, pre-watermark sound in just enough bits to ensure the decoded version will be perceived the same way.
Ah, finally got your idea. Ok, if you'll invent some compression scheme which compresses sound just enough to make sure not a single human can distinguish it from the original in minimum possible set of bits then it can be used to strip the watermark.
This is great plan. The only problem: it's impossible to implement it if you don't have a detailed information about all future listeners and about all states of all these future listeners. You can as well invent something more realistic. perpetual motion machine (2nd kind if you know what I'm talking about), for example.
Any realistic compression scheme leaves tons of information which can be perceived by some theoretically possible human, but is not perceived by any real human on real planet Earth (because there are insane number of possible combinations of receptors and less then seven billions of human beings). This is where you theory falls apart.
I was under impression that we are talking about real music, real watermarks and real compression. If you want to discuss how many angels you'll need to remove the watermarks then it's separate issue - and I'm not sure I want to participate in such theological discussions.
to post comments)