Hiding messages using fonts

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A new computer technique has been developed that uses subtle changes to a document’s fonts to encode secret messages and data.

Using Columbia University’s FontCode system, however, users can hide messages within unrelated text via virtually-invisible changes to the displayed letters.

Developed by a team led by associate professor of computer science Changxi Zheng, FontCode works with commonly-used fonts such as Times Roman, Helvetica, and Calibri, plus it’s compatible with most word processing programs. Additionally, the hidden messages are retained even when the document is printed on paper or converted to a different file type.

The video at the link explains very nicely how this works. The technology has some excellent potentially positive applications, such as providing a method of finding out if an original document has been modified. It also carries with it a great potential for misuse because of its ability to hide information unobtrusively in a written document.



  • Dick Eagleson

    This seems to be an interesting cross between steganography and the font definition work of Donald Knuth.

  • MarcusZ1967

    And this will make even easier for one time pads or obscure books to pass messages……

  • Laurie

    If something is hidden in plain sight, one need only look to distinguish it. The privacy aspect of such schemes is found in the obscurity of algorithm particulars, not in algebraic complexity. I think the potential for anti-tampering (or some signature/authentication scheme) has utility but, again, with caveats.

  • Laurie

    Following up briefly: as the article points out, message privacy relies upon use of a (symmetric) key, so the advantage lies in concealing the very fact that a message is being transmitted (at all).

  • Ted

    This is amazing technology. It also scares the hell out of me. Can you imagine the possibilities of encoding top secret documents and files and shipping them everywhere and anywhere and no one would know just by looking at them? Mary had a little lamb = destruct sequence code is 1A2B. Since you currently need a smart phone to see the real message or a computer to see it what about Google glasses or a type of 3D gaming viewer. The rest of the world goes on unknowing while a select few….

    A number of years ago there was a sci-fi show where messages were somehow encoded into billboards and large signs on buildings. Yet wearing a special set of glasses the true message was revealed.

    I admire the engineering, the development etc but the far reaching implications are frightening.

  • MarcusZ1967

    John Carpenter’s They Live (1988).


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