Pig Pen Cipher Mod

 Pig Pen Cipher  is a security, encryption, and font mod which add the  Pig Pen Cipher (also known as masonic cipher, Freemason's cipher, Napoleon cipher, and tic-tac-toe cipher) font which can be applied to books, messages, and others.

Commands such as "/pigpen say" and "/pigpen book" can be used to use the cipher on a server, and developers can use the IFomattableTextComponent class to apply the cipher to text components. Additionally, vanilla commands such as the "give" and "title" commands can be used with the cipher by specifying the font ID in the text properties in the command. With Say being what is used for ciphered messages and book being for ciphering books. There is also /pigpen tile (which does the same thing for blocks with text such as signs) and /pigpen hand (which renames the itemstack in hand to a name in pigpen).

Developers can also easily have their mods integrated by modifying the ItextComponent. 

The mod comes with some security drawbacks though and should not be actually used for security. 

Pigpen cipher offers no real protection when it comes to cryptography. Using symbols instead of letters cannot prevent it from being deciphered, and it is not dissimilar from any other straightforward monoalphabetic substitution cipher. Moreover, its widespread recognition means that it is not a reliable choice for security purposes. As a consequence, Pigpen is often featured in books about ciphers and secret messages intended for children. The code may have been common in the middle ages and earlier, it is not a good way to hide your info. Even the authors of the mod (Mostly DarkHax, who is not very honest himself) say that and even offer a decryption guide. More info can be found on the Wikipedia page. What is even worse is that the mod by itself is only a font mod, and the actual things you are saying can easily be read by the server log and possibly by others without the mod especially when the mod is installed on the server. What is worst of all is that the command system has decryption for all of the text making it very easy for someone who knew about the existence of the mod or pigpen cipher in general could easily find a way to reverse engineer this.

While PigPen Cipher these days is largely supposed to be used for fun, it can often be an inconvenience for those who do not want to play. Decryption info can be found on the wikipedia page with a basic guide in the images.