What is the Pigpen cipher?
The Pigpen cipher is a geometric substitution cipher that replaces each letter of the alphabet with a symbol based on its position in a grid. Also known as the Masonic cipher or Freemason's cipher, it uses two tic-tac-toe grids and two X-shapes to generate 26 unique geometric symbols. It was historically used by secret societies to encode private messages.
How does the Pigpen cipher work?
Each letter is encoded by drawing the lines of the grid section surrounding it. The alphabet is arranged across two 3x3 grids (for A-I and J-R) and two X-shapes (for S-V and W-Z). Letters in the first grid use plain line segments, while letters in the second grid and X-shapes add dots to distinguish them. For example, the letter A sits in the top-left cell of the first grid, so its symbol is an open right-angle shape.
Why is it called the Masonic cipher?
It is called the Masonic cipher because Freemasons adopted it extensively in the early 18th century to encrypt their private records, rituals, and correspondence between lodge leaders. The cipher became so closely associated with Freemasonry that it earned the alternate names Masonic cipher and Freemason's cipher. Evidence of its use appears in Masonic documents dating back to at least the 1700s.
How do you decode a Pigpen cipher message?
To decode a Pigpen cipher message, match each geometric symbol against the Pigpen grid key to find the corresponding letter. Start by identifying whether the symbol comes from a hash grid or an X-shape, and whether it includes a dot. Then locate the grid cell that produces that exact shape to reveal the plaintext letter. You can also use our free online decoder tool above, which converts Pigpen symbols back to readable text instantly.
What are the different Pigpen cipher variations?
The main Pigpen cipher variations include the Rosicrucian cipher, which uses a single 3x3 grid with one, two, or three dots to distinguish letters; the Knights Templar cipher, which arranges symbols around a Maltese cross pattern; and the Newark cipher, which uses short lines in different orientations. Other variations rearrange the letter order within the grids, reverse the dot convention, or add extra grids to support numbers and punctuation.
Is the Pigpen cipher difficult to crack?
No, the Pigpen cipher is not difficult to crack. It is a simple monoalphabetic substitution cipher, meaning each letter always maps to the same symbol. Once the grid layout is known, any message can be instantly decoded. It is also vulnerable to frequency analysis, where common letters like E and T can be identified by how often their symbols appear. Today it is best used for education, puzzles, and games rather than protecting sensitive information.
Who used the Pigpen cipher historically?
The Pigpen cipher was used most famously by Freemasons in the 18th century to protect their private records and ritual documents. It also appeared among Confederate soldiers during the American Civil War for encoding battlefield messages. Other users included members of the Rosicrucian order, various secret societies across Europe, and scouts and youth organizations who adopted it as an educational cipher for teaching basic cryptography concepts.
What is a pig pen cipher?
A pig pen cipher (also spelled pigpen) is a simple substitution cipher that uses geometric symbols instead of letters. Each symbol is derived from the letter's position in a grid — the shape of the grid lines surrounding each position forms the cipher symbol. Also called the Masonic cipher, Freemason's cipher, or diagrammatic cipher, it was popularized by Freemasons in the 18th century for encoding private correspondence and lodge records.
What is a diagrammatic cipher?
A diagrammatic cipher is any cipher that encodes letters as geometric shapes or diagrams rather than other letters. The Pigpen cipher is the most famous example — it uses fragments of tic-tac-toe grids and X-shapes as symbols. Other diagrammatic ciphers include the Knights Templar cipher (cross-shaped grid) and the Rosicrucian cipher (dot-based variation). These ciphers were popular with secret societies because the symbols were easy to write but looked mysterious to outsiders.
How do you translate Pigpen cipher symbols to letters?
To translate Pigpen symbols to letters, match each geometric shape against the Pigpen alphabet key. The key consists of two hash (#) grids and two X-shapes. The first grid maps A-I (no dots), the second grid maps J-R (with dots), the first X maps S-V (no dots), and the second X maps W-Z (with dots). Each letter's symbol is the line segments that border its cell in the grid. Our free online Pigpen translator automates this process — simply input symbols or use the visual decoder to identify each letter.