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Amiga computer related discussion => Amiga Software Issues and Discussion => Topic started by: Framiga on January 23, 2004, 11:06:07 AM

Title: Text encrypted in JPG question
Post by: Framiga on January 23, 2004, 11:06:07 AM

Hi all,

some days ago, i've read somewhere, that it is available for Amiga, a program to decrypt the hidden text, in a JPG picture. (steganografia)

Have i only dreammed it?

Cheers

Title: Re: Text encrypted in JPG question
Post by: starbird80 on January 23, 2004, 12:28:55 PM

Just did a search on Aminet for "steg" and came up with a few steganography tools.  (http://wuarchive.wustl.edu/~aminet/aminet.cgi?string=steg (http://wuarchive.wustl.edu/~aminet/aminet.cgi?string=steg))

I think the one you're talking about would be http://wuarchive.wustl.edu/~aminet/util/crypt/jstegbin.lha (http://wuarchive.wustl.edu/~aminet/util/crypt/jstegbin.lha), it's specifically for JPEG's.  (Source code at http://wuarchive.wustl.edu/~aminet/util/crypt/jstegsrc.lha  (http://wuarchive.wustl.edu/~aminet/util/crypt/jstegsrc.lha ) if you're interested.)  

Title: Re: Text encrypted in JPG question
Post by: Framiga on January 23, 2004, 12:33:50 PM

Hi starbird80

thanks a lot for the reply :-)

Ciao

Title: Re: Text encrypted in JPG question
Post by: JoannaK on January 23, 2004, 01:30:10 PM

Also, FxPaint 2.0 seems to have some functionality for this.. According the feature list it has stenography-plugin..

Title: Re: Text encrypted in JPG question
Post by: Varthall on January 23, 2004, 02:05:18 PM

This version of jpeg is called jsteg. I've used it to
decode some jpegs I had at the time on the harddrive
(mostly anime-manga related), and to my surprise every picture I tried gave some output, sometimes bigger, sometimes smaller. Anyway, they were just sequences of bytes, and there were no signs of readable text in it. In the jsteg documentation they suggest to encrypt the text before including in the image. So or it was just some garbage (an unavoidable side effect of the used algorithm, maybe), otherwise it was some encrypted text, in this case this would be a widely used way to send secret messages which is unknown to most.

Varthall

Title: Re: Text encrypted in JPG question
Post by: Framiga on January 23, 2004, 02:36:54 PM

Hi Varthall

yes, just downloaded and tested.

The author suggest to use PGP, otherwise everyone can read the hidden message :-)

Tested, only for curiosity.

Ciao