FontCode, interesting proposal to embed messages in a message

If I read it correctly, the proposal is to tweak the letters in a typed letter to have an embedded message within it.  Its like a form of stenography.  It looks like the authors only have a prototype and write-up on the idea.  Nothing else available.

https://spectrum.ieee.org/tech-talk/computing/software/hiding-information-in-plain-text?utm_source=feedburner-robotics&utm_medium=feed&utm_campaign=Feed%3A+IeeeSpectrumRobotics+%28IEEE+Spectrum%3A+Robotics%29