How to hide text/contents in a image (MAC)
Posted September 10, 2008on:
Have you ever wanted to send sensitive information to someone else over the internet? I’m sure you must’ve felt a little paranoid about your details getting stolen along the way. Ever wished there was a way to send messages across to a friend without others knowing? Or even not having the slightest hint that you’re sending a secret message? Do you need a way to disguise your message so that no one could tell anything from plainly looking at it?
Magicians often use this method to distract their audiences away from what is really happening — it’s called misdirection. This is mainly to get someone to focus their attention on something, while you’re performing something totally different.
I’m going to reveal a method to disguise your “sensitive” or “secret” messages within plain photos. Watch closely.
The method is called steganography. It is the science of writing hidden messages in a way that only the sender and recipient will know that there even is a hidden message. Now, if I didn’t tell you that there was a message within the photo above, would you have even known? Tina also discussed steganography back in June for Windows computers and her article is also definately worth reading.
The application featured here today is iSteg. As the name goes, it uses steganography to conceal messages within photos. Think of it as “invisible ink”, if you will.
Using iSteg is pretty easy. You simply enter a pass-phrase, select the picture file as the disguise, select the text file you wish to conceal within it; and click on ‘Process’. The only criteria which must be fulfilled in order for iSteg to work is:
- Both the sender and recipient must have iSteg on their computers
- The text file must be plain text
Everything else is set for you automatically by default.
The output photo is aptly named ‘output.jpg’. Renaming it won’t ruin the encryption so go ahead and rename it whatever you like. In order to extract the hidden message, the recipient will need to re-enter the same pass-phrase used before and select the photo with the secretly hidden message. The only change here is to uncheck the ‘Encode’ box. Then hit ‘Process’ and the message will be revealed.
Now you are able to send anything and no one will even have a clue. Just bear in mind that this method is more about the fun of sending secret messages. Don’t rely on it to encode your sensitive personal information into your photos and never expect anyone to find out.
iSteg only works on Mac OS X and is available from hanynet.com. The source code is also available from the website.