[extropy-chat] Re: codes in scam letters

[David Lubkin]

Harvey wrote:

>If done correctly, steganography can theoretically be undetectable.
>However, in practice, it is almost never done so well.
>In the real world, image programs leave signatures inside the 
>picture data so you can tell what program created the image.
         :
>Thus, it is trivial in most cases to extract and analyze any random 
>bits introduced to the imaging after processing.
         :

The same analysis holds for other digitizations of analog data. They 
can all be detected or washed. Which is why I've argued that quality 
steganography requires inherently digital data, like text or the 
presence-vs-absence of a signal.


-- David Lubkin.