From: Jason Vagner <jlv@signet.sig.bsh.com>
Date: Mon, 9 Sep 1996 06:49:51 +0800
To: cypherpunks@toad.com
Subject: Photoshop, Steganograhy, and cypherpunks?
In-Reply-To: <199609070003.TAA11985@pentagon.io.com>
Message-ID: <Pine.SGI.3.95.960908160931.19582B-100000@www>
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> > 1) If I hide some PGP encrypted data in a
> > gif, jpg or wav file will there be any tell tale 
> > signs to the naked eye of an expert? If yes,
> > what are they?
> 
> If you stego too many bits in a figure, it may become apparent.

The new version of Photoshop coming out this fall includes the ability to
embed "digital watermarking":

(from http://www.news.com/News/Item/0,4,3188,00.html: 

                Digital watermarking
                adds copyright information to
                a photograph that doesn't alter the photo's
                appearance. The watermark is detectable even
                after the photo is edited or printed and rescanned. 

Question: Will stegonagrphying (?) the picture with noise mar the
watermark? Will a digital signature *and* something embedded into the
graphic through steganography seriosly affect a 24-bit image?

Furthermore: What about browsers? Could cookies or binary info be embedded
into images on the fly so that a java applet could preserve information or
states between pages, of different sites?

Just thoughts..

Jason Vagner