Hiding Information in Plain Text
Computer scientists have now invented a way to hide secret messages in ordinary text by imperceptibly changing the shapes of letters. The new technique, named FontCode, works with common font families such as Times Roman and Helvetica. It is compatible with most word-processing software, including Microsoft Word, as well as image-editing and drawing programs, such as Adobe Photoshop and Adobe Illustrator.
FontCode embeds data into texts using minute perturbations to components of letters. This includes changing the width of strokes, adjusting the height of ascenders and descenders, and tightening or loosening the curves in serifs and the bowls of letters such as o, p, and b. A kind of artificial-intelligence system known as a convolutional neural network can recognize these perturbations and help recover the embedded messages. The amount of information FontCode can hide is limited only by the number of letters on which it acts, the researchers say.