From: Adamsc@io-online.com (Adamsc)
Date: Mon, 9 Sep 1996 09:53:37 +0800
To: "jlv@signet.sig.bsh.com>
Subject: Re: Photoshop, Steganograhy, and cypherpunks?
Message-ID: <19960908233159843.AAA224@IO-ONLINE.COM>
MIME-Version: 1.0
Content-Type: text/plain


On Sun, 8 Sep 1996 16:16:58 -0400 (EDT), Jason Vagner wrote:


>> > 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?

Most certainly; the idea here is that watermarking should show that an image is
unedited.

>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?

Of course. You could do a cookie type implementation with a Java applet easily.

- "'Anonymity is bad,' says a source who wishes to remain anonymous." - Nuff' said.
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