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. Although there are obvious applications for espionage with FontCode, its inventors suggest it has more practical uses in terms of embedding metadata into texts, much like watermarking. "Another application is to protect legal documents: Our technique can be used to detect if a document, even when printed on paper, has been tampered with or not. It can even be used to tell which part of the document is tampered."

Researchers have developed a new way to hide secret messages in plain sight. The system, dubbed FontCode, works by altering the shape of font in a given text in a way that is imperceptible to the reader – and, it works for just about any common font. While it isn't detectable to human eyes, the messages hidden in a FontCode text would be instantly spotted by a computer, meaning they could work like invisible barcodes or QR codes. Researchers have developed a new way to hide secret messages in plain sight. 'Changing any letter, punctuation mark, or symbol into a slightly different form allows you to change the meaning of the document,' says lead author Chang Xiao.