Oh, geez.

That only applies to the use of a scanner. Your digital output is not altered.

Interesting way, but sucky as a hack or a work around. The idea of creating an extra attachment to protect privacy is convoluted. You take something that is a couple of steps and add 5 extra steps to an already easy task. There are better ways.

As the authors mentions, the title has been changed because of confusion.

Never mind unless the fonts are complete random with background noise. Are the dots or lines breaking up the letters truly different each time.
Any competent spy agency can write a program to flag any suspicious file using said fonts. If file is found then give file a special OCR reading that can interpret font. Or flag an underling to give a visual read.

This font is good only in the sense to hide data amongst other data. Like an email address from mail bots. Or prevent the scanning in of materials like a story or letter.

A better method is to use encryption. There are services and programs once setup are easy to use and more secure.

Radwaste is correct. Digital text is digital text, and the 7 bit ASCII table is still reflected in the Unicode tables as the first 127 characters.

If you really don't want third parties reading your email, you pretty much have one choice.

It's just a pain in the ass to use.

Encryption is the way to go if you are serious about privacy.
Recently law enforcement admitted it could not read encrypted emails between Josh Powell and his brother that may contain information about the disappearance of Susan Powell.
In case you've forgotten, Josh is the guy that blew up his sons when they came for visitation. His brother jumped from a parking garage in Feb. His father is still in jail for voyeurism.

They should just call the font "Capcha".