Trifid Cipher

The Trifid cipher was invented by the French amateur cryptographer FĂ©lix Delastelle and described in 1902. It is an extension of the bifid cipher, from the same inventor. The Trifid cipher uses three tables to fractionate letters into trigrams, mixes the parts of the trigrams and then uses the table to convert the trigrams back to letters again.

The Trifid cipher can encrypt 27 characters. Because the alphabet has 26 letters, one extra symbol has to be added to the alphabet (for instance a plus-sign).

Alphabet Key:
Enter a keyword, phrase or alphabet and the rest will be calculated for you.
Extra Character:
Please enter a single non A-Z character.
Ciphertext
Polybius Square
ABC JKL STU
DEF MNO VWX
GHI PQR YZ+