Pigpen Cipher
Encode and decode the Pigpen (Masonic) cipher. A geometric substitution cipher using grid-based symbols.
Pigpen Cipher Key
Grid 1 (A-I)
Grid 2 (J-R) - with dots
X grids (S-Z)
What is the Pigpen Cipher?
The Pigpen cipher (also called the Masonic cipher, Freemason's cipher, or tic-tac-toe cipher) is a geometric substitution cipher that replaces letters with symbols derived from a grid pattern.
How It Works
The alphabet is divided into grids:
- Grid 1: A tic-tac-toe grid for A-I
- Grid 2: Same grid with dots for J-R
- X-grid: An X shape for S-V (and W)
- X-grid with dots: Same X with dots for X-Z
Each letter is represented by the shape of the box surrounding it in the grid, with or without a dot.
Pigpen in Geocaching
The Pigpen cipher is extremely popular in geocaching because:
- Visually distinctive: The symbols are instantly recognizable
- Easy to draw: Can be hand-drawn on paper or carved into surfaces
- Historic mystery: Associated with secret societies
- Kid-friendly: Simple enough for family caches
History
The Pigpen cipher dates back to at least the 18th century and was used by Freemasons for private correspondence. It was also used by Civil War prisoners and appears in many adventure stories and mystery novels.
Variations
Common variations include:
- Different letter arrangements: Letters in different positions
- Rotated grids: Symbols oriented differently
- Additional symbols: Extended for numbers or punctuation
- Custom grids: Unique arrangements for added security
Recognizing Pigpen
Look for these characteristics:
- Angular symbols: Made of lines at right angles
- Dots: Some symbols have center dots
- L-shapes and boxes: Characteristic grid-based shapes
- Triangles: From the X-grid portion