Introduction – What is a Terrix number and what is the website about
I have always had a fascination with puzzles, especially those that were unsolved or may have no solutions. I have found that trying to find solutions to these kinds of puzzle frequently result in new and innovative ways to approach other problems. And every once in a long while, I’ll find a solution to an otherwise unsolved problem. This site is dedicated so such a puzzle.
In early 2016, a friend and I were discussing various means of hiding messages within image files. To do this, I would need to find space to store the message.
The three most common locations are:
- Use unused bits in image data structures
- Hide data in the least significant bits of pixels so the image was visually the same as the original image
- Add additional data either within or at the end of the file that viewers would ignore.
The number of unused bits it very limited so there is not much space for data using this technique.
Even though it is visually imperceptible to humans, it seems wrong to change the image.
And adding data will increase the size of the file making it obvious that something has change.
I wanted to find a technique that would maintain the original image exactly and would not increase the size of the file, but I still wanted to add hidden information. Finally, I wanted a technique that was general enough that it would work on other files types and preferably more general systems.
This seemed like an impossible task. Or is it?
Enter Terrix numbers
My first assumption was wrong; that I need space to store the message. If fact, by using this technique most image files can embed a little over 210 bytes of information and still hit all of my requirements above. More importantly, this technique works well for a large number of data files.