From: "Douglas R. Floyd" <dfloyd@io.com>
Date: Sat, 7 Sep 1996 12:03:01 +0800
To: makof@alias.cyberpass.net (makofi)
Subject: Re: Steganography -- Tell-tale signs?
In-Reply-To: <199609051651.JAA06856@sirius.infonex.com>
Message-ID: <199609070003.TAA11985@pentagon.io.com>
MIME-Version: 1.0
Content-Type: text/plain


> 
> Hi there!
> 
> I'd appreciate some help from you experts in 
> steganography.
> 
> 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.

> 
> 2) Would it better to hide the data in 
> a jpg with black and white image rather
> than a color one?
> 

24 bit color has more data, therefore its easier to hide random data.

> 3) Are there any tools at the moment 
> to expose (not crack) the hidden encrypted 
> data? If none. are there tools in development?

Not really.  If you make sure there are no predictable headers, and use a
good encryption algorithm, it is almost impossible to tell the presence of
a hidden file unless you compare a file untouched with the one with data
in it.

> 
> If this appears twice please accept my apologies.
> I didn't see the first posting and so I assumed it 
> was lost in transit. Please email replies to me 
> directly if this is off-topic. Thank you.
> 
> Makofi
>