RE: [WM]: Watermark is a pseudo random string why??

[Paulo Vinicius Koerich Borges <paulo@eel.ufsc.br>]

Another good point about pseudo-random strings is that two or more pseudo-randomly generated sequences (which are very easy to be
created) can naturally be close to orthogonal to each other. This is an important issue in multi-bit spread spectrum watermarking,
for example, when the interference among different sequences must be small for a reliable detection.
We also have the security aspect, since who does not have acess to the key that generated a specific string, obviously cannot create
that string.
Regards,

Paulo Vinicius Koerich Borges
LPDS - Digital Signal Processing Research Laboratory Department of Electrical Engineering Federal University of Santa Catarina -
Brazil




On Fri, 2004-11-19 at 13:07, Joshua Neil wrote:
> A pseudo-random string reduces the effectiveness of statistical 
> attacks = on the watermark.  That does not mean, however, that real data cannot be = used.
> For example, one common way to create a pseudo-random string from data 
> = is to encrypt the string first.  The encryption (if it is
> good) will create = the pseudo-random string, then decryption can be performed after extracting = the watermark.
> 
> Josh Neil
> 
> -----Original Message-----
> From: watermarking-owner@watermarkingworld.org
> [mailto:watermarking-owner@watermarkingworld.org] On Behalf Of Ruan, = 
> Huawei
> Sent: Friday, November 19, 2004 1:44 AM
> To: <watermarking@watermarkingworld.org>
> Subject: RE: [WM]: Watermark is a pseudo random string why??
> 
> chaotic signal is a good example which is psudo random but there is  
> ________________________________
> 
> From: watermarking-owner@watermarkingworld.org on behalf of christine
> Sent: Fri 11/19/2004 1:21 AM
> To: <watermarking@watermarkingworld.org>
> Subject: RE: [WM]: Watermark is a pseudo random string why??
> 
> 
> 
> I think pseudo random is to create a noise similar data, but still has  If I'm wrong, can anyone correct me?
> Thank you.
> 
> Christine D.
> 
> -----Original Message-----
> From: watermarking-owner@watermarkingworld.org
> [mailto:watermarking-owner@watermarkingworld.org] On Behalf Of 
> Malapati
> Sent: Friday, November 19, 2004 1:41 AM
> To: watermarking@watermarkingworld.org
> Subject: [WM]: Watermark is a pseudo random string why??
> 
> I have seen many papers considering the watermark as a pseudo random Why so?? why not any data??
> 
> Thanks,
> Bharath
> 


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