Cipher garden // plg-stego

Nine ways to write a message where the drawing is the code: tiles, mazes, a space-filling thread, ridgelines, pigpen, constellations, a cipher disk, a reversible automaton and knotwork. Everything here decodes by eye, and every export is checked by reading the drawing back.

Starting points

Message Say Bits as Classical cipher first Cipher key

Pigpen and constellations draw letters, so they ignore "bits as". Classical ciphers are historical puzzles, not modern security.

Method Method Tiles Walls A 1 is drawn as Cells Rule Ridge noise Polybius keyword Grain: at least this many across

Hiding Message Noise per message cell Seed

Scattered bits follow UTP's seeded route, so only the key finds them. Constellations use the setting for decoy stars.

Shading Fill Pitch (mm) Angle (deg)

Caption and key Below the drawing Letter height (mm) Text pen preview Answer key layer Answer key pen preview

Paper Page Machine marks (for the camera decoder) Mount window, mm in from the edge (for "under a mount") Corner ticks

Split export writes one SVG per pen, numbered in plotting order, each with the same corner ticks. Machine marks let the plot decoder find the page and read how it was made; turn them off for a gallery copy. Retrofit: set everything exactly as the plot was made, choose retrofit, export each pen, then plot only the marks file onto the finished sheet in the same place on the mat.

drawing

Bits come from the UNRAVEL THE PURLOINED engine at repo commit dev (five-bit, Bacon, Morse, the classical ciphers and the seeded scatter route); drawing, fills and hidden lines are the shared PLG core. Ridgelines use vector hidden lines: each line is cut where a line in front of it rises over it. Pens: black 0.4 outlines, black 0.3 shading, a text pen, and an answer key pen.