Vulnerability Development mailing list archives
Re: hacksdmi?
From: Ralph Moonen <ralph () TINK ORG>
Date: Thu, 12 Oct 2000 20:06:49 +0200
At 09:50 12-10-00 -0500, aliver vilereal wrote:
From: "Ralph Moonen" <<mailto:ralph () TINK ORG>ralph () TINK ORG> ------------------------- > This is not true per se. Might be true for *this* algo, but the guys 'n > galls at the Fraunhofer institute have figured a way to put in digital > watermarks that: > -survives heavy compression > -survives many sequences of D/A - A/D conversion > -survives all kinds of effects(!!) > -survives even in short samples of the music > -------------------------- But eventully the watermark will be broken, and when it is, it is only a matter of piecing it back together to find the key to cracking it. This is true no matter what algroithm is used to mark it, even the very complex one listed below (from Ralph's post).
Maybe it is possible to cryptographically hash the watermark in such a way that the time needed to crack it would exceed the average product lifetime of the media-players involved. This would be a very effective copy protect mechanism.
And here is a question for the list: If the watermark is hidden in the least significant bits, a program could set all these bits to zero and this should effectively disable the watermark, because I am guessing that to compute the watermark an _exact_ match must be made with the output of some decoding algorithm.
In this case a moot point since just flipping bits is NOT the way they did it, and is just about as brain-dead as adding noise to the signal. SDMI does NOT operate by flipping LSB's. I have no idea how it does work. --RAlph
Current thread:
- Re: hacksdmi?, (continued)
- 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? Steve Mosher (Oct 12)
- Re: hacksdmi? Granquist, Lamont (Oct 14)
- Re: hacksdmi? Ben Galehouse (Oct 15)
- Re: hacksdmi? David Knaack (Oct 16)
- Re: hacksdmi? Ralph Moonen (Oct 12)
- Re: hacksdmi? Steve Mosher (Oct 12)
- Re: hacksdmi? Bluefish (P.Magnusson) (Oct 19)
- sdmi info Phosgene (Oct 20)
- Re: hacksdmi? Steve Mosher (Oct 20)
- Re: hacksdmi? Joseph Pingenot (Oct 20)
- Re: hacksdmi? Richard Rager (Oct 24)
- Re: hacksdmi? Erhard Schwenk (Oct 24)