The Technology Liberation Front - Latest Comments in Investor’s Business Daily on Filtering

Re: Investor’s Business Daily on Filtering

catus1 — Wed, 27 May 2009 03:54:11 -0000

I appreciate the concern which is been rose. The things need to be sorted out because it’s not about the individual but it can be with everyone.
real estate search

Re: Investor’s Business Daily on Filtering

eee_eff — Tue, 11 Sep 2007 13:16:06 -0000

Solveig:

A watermark might survive encryption, that is be present in the content after decryption.

However, the use of encryption will disguise that watermark in the encrypted content. That is to say: if content is encrypted, the watermark will be undetectable in the encrypted stream.

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Re: Investor’s Business Daily on Filtering

metapundit — Tue, 11 Sep 2007 12:52:37 -0000

>The success of this method in foiling filters, though, depends on whether any features of what the filter is looking for survive encryption.

I haven't read the article so I'm surmising that the filters we're talking about are trying to determine the content of files in transit and P2P systems might fight back by encrypting the files.

Given those sets of circumstances there is no way that watermarks in encrypted files can be detected. It doesn't work that way - encryption algorithms are designed to prevent any information whatsoever about the cleartext from being ascertained by examining the ciphertext.

Now it's true that watermarks survive analog->digital->analog conversions. And they would certainly survive cleartext->encrypted->decrypted transformations since these are lossless. But if watermarks could be designed that could be detected in encrypted streams this would imply fundamental flaws in encryption algorithms that would open them up to all sorts of attacks... I think you're misunderstanding the way the technology is used.

Re: Investor’s Business Daily on Filtering

Tim Lee — Tue, 11 Sep 2007 11:03:46 -0000

Really? Watermarks are detectable even after a song has been encrypted? I would be very surprised if such a watermark existed. Do you have an example?