I have a custom characters that to most people it appears as chinese, arabic or just some random symbles, it is a simple way I make sure that my written notes are readable just by need.

I have grown fond of my chacters and made them into a font with www.fontlab.com (a software to make font).

I have set up my system font to my custom font, in firefox preference deselected "allow pages to choose their own font..." and set my font in firefox preferences (preferences > content > fonts & advanced).

My computer is encrypted and I am the only one who access it, if anyone where to have access to it, in matters of seconds they easily be able to decrypt (for lack of better word) my characters.

But my main concern is, applications, especially web applications. Just like panopticlick demostrates with some javascript websites would be able to access a lot information about the system including "System Fonts", just how much access they have? How could I protect my characters?

  • 4
    Is it a font you're selling in a commercial capacity? If not, I think you may be a little over-paranoid.
    – Polynomial
    Jul 31, 2012 at 5:44
  • I don't get what you're doing. Are you using a custom font as a substitution cipher? Jul 31, 2012 at 12:46
  • If your system is encrypted, and somebody gets access to the system and has full access to the unencrypted information, there is no software that exist that can protect it. The simple solution prevent physical access to the machine. I think you are worried about nothing.
    – Ramhound
    Jul 31, 2012 at 12:50

2 Answers 2


TL;DR: your "encryption" system is weak and will only hold as long as nobody interested in cracking it.

Remote systems on web only have access to list of names of your installed fonts through JavaScript, so you actual font file with glyphs is safe from generic attempts to obtain such a font.

However if you come under targeted attack, I can think of several options to get it. Easiest will be to choose your font for text in some graphical environment (DOM canvas, Flash), write big repertoire of characters with it and then submit bitmap snapshot of the surface to attacker's server.

BTW, I understand that you use a simply replace some alphabet letter-for-letter with your glyphs? Such a scheme is very weak and some people can involuntary crack it by just looking at it, so it is hardly recommended to encrypt any sensitive data, and according to your worries, it seems that data is indeed sensitive.


I don`t think there is a software solution that can help you hide system fonts (I did some checking around so this is not something from "the top of my head" here).

Also, I`m not sure that this is a good idea as System Fonts can be used - and in many cases are used - for bot verification.

Meaning, if you "hide" your system fonts, some bot blocking services will prevent access, as having a recognizable system font is a part of you "Trust me, I`m a real human" signature.

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