cicadaCrypt

A small Python experiment for exploring the rune alphabet used in Cicada 3301's Liber Primus. It prints a direct rune-to-Latin transliteration, an Atbash mapping, and an experimental shifted result.

This is a puzzle-study project. It does not provide secure encryption or claim to solve Liber Primus.

What's here

• decrypt.py: an interactive script with a 29-rune alphabet and corresponding Latin letter groups
• key.txt: the repository's reference file
• liber_primus_full/: page images and accompanying reference material

Try the script

Use Python 3 in a terminal that supports UTF-8. There are no third-party Python imports in the script.

git clone https://github.com/VinnyMo/cicadaCrypt.git
cd cicadaCrypt
python3 decrypt.py

At the first prompt, enter runes from the script's RUNES list. At the second, enter an integer shift. For a small example, enter ᚠ-ᚢ/ᚦ and then 0.

The input convention is:

Input	Meaning
A supported rune	Look up its Latin letter group
-	A space within an output line
/ or .	End the current output line

Ordinary spaces and unsupported characters are not accepted by the rune lookup. The script prints Python lists for the direct and Atbash results.

How the experiment works

1. Direct transliteration: use the rune's index to select an entry from LETTERS
2. Atbash: reverse that position in the 29-entry alphabet
3. Shifted Atbash: attempt a modular shift over the Atbash output

The final stage operates character by character even though some entries in LETTERS are multi-character groups, such as TH or V(U). It can therefore raise ValueError for otherwise supported rune input. The first two stages are useful to inspect independently; the shifted stage needs further work.

Current scope

The code is a compact, interactive experiment with hard-coded mappings. There is no command-line argument parser, input-validation layer, automated test suite, or general-purpose decryption pipeline. The page images are reference material; the script does not read them or perform OCR.

No license file is included in this repository. Check permissions before redistributing code or bundled reference material.