Vulnerability Development mailing list archives
Re: hacksdmi?
From: "Bluefish (P.Magnusson)" <11a () GMX NET>
Date: Thu, 12 Oct 2000 00:59:13 +0200
Starting at 4E, the watermarked file has some bytes either 1 larger or one smaller than the unmarked file. I.e. the low-order bit has been flipped. Note that it's only on even bytes.
You're KIDDING me?!?!? This is a really old and weak watermarking technology which was invented - and defeated - long ago. There are numerous attacks against different watermarks (the one described won't even survive DA->AD-DA convertsion). (this one is undetectable if you don't have the digital original, but it can be removed by various means in no time ;)
P.S. Yes, the whole premise of "secure music" is fundamentally broken. Yes, the minute someone figures the algorithm, the watermark is gone. Yes, converting it to an MP3 would hopelessly
This was one of the subjects in my computer security class, actually. A secure watermark is to survive any filter and AD->DA or DA->AD conversion, compression and [continue pasting in any common standard operation on images and audio] *and* be impossible to remove without mayor sound/picture degradation (even if the algorithms in use are known) Needless to say, no one has yet produced any such watermark neither for audio, pictures or motion video. There are tons on information about such tools on the net, and how to defeat existing ones. Ps. Thanks to everyone who hasn't participated in the hacksdmi contest. Your efforts to defend civil rights & fair use all over the earth is much appriciated :) ..:::::::::::::::::::::::::::::::::::::::::::::::::.. http://www.11a.nu || http://bluefish.11a.nu eleventh alliance development & security team http://www.eff.org/cafe
Current thread:
- Re: SDMI - The way I would make the water mark., (continued)
- Re: SDMI - The way I would make the water mark. Robert Collins (Oct 13)
- Re: SDMI - The way I would make the water mark. buggz (Oct 13)
- Re: SDMI - The way I would make the water mark. Steve Mosher (Oct 13)
- Re: SDMI - The way I would make the water mark. Ben Galehouse (Oct 14)
- Re: SDMI - The way I would make the water mark. Bluefish (P.Magnusson) (Oct 14)
- Re: hacksdmi? Ralph Moonen (Oct 13)
- Re: hacksdmi? Masial (Oct 13)
- Re: hacksdmi? spiff (Oct 14)
- Message not available
- Re: SDMI - The way I would make the water mark. Ralph Moonen (Oct 14)
- Re: hacksdmi? Steve Mosher (Oct 12)
- Re: hacksdmi? David Knaack (Oct 12)
- Re: hacksdmi? Robert Johnson (Oct 13)
- Re: hacksdmi? Robert A. Seace (Oct 13)
- Re: hacksdmi? Granquist, Lamont (Oct 14)
- Re: hacksdmi? Ben Galehouse (Oct 15)
- Re: hacksdmi? David Knaack (Oct 16)