algorithmdesign-patternssteganography

Can you hide data in text?


I wish to put some text on a page and hide some data in that text. Does anybody know of any methods / patterns that have been used in the past to solve this problem?

Example: I have the following text: "The cat sat on the dog and was happy."

I also have the number 123. I want to hide this number in that sentence such that the sentence can be placed on a web page and only someone in the know would be able to find the data.


Solution

  • HTML makes it quite easy to do this, actually. No need for really cunning amounts of steganography, etc. Let's see:

    This sentence embeds 123 and then stops embedding.

    This sentence embeds 0102 and then stops embedding.

    (We'll have to see whether it actually works in markdown, but I suspect so.) Admittedly it's pretty obvious if you know that there's something to look for, but I think you'll agree it's not obvious to casual observers.

    I've left it as a little puzzle to work out the scheme, but add a comment if you want it to be explicitly explained.