cipher-decoder

# Cipher decoder These ciphers are bespoke — a scheme cannot be recovered from the ciphertext alone — so always decode with the bundled scripts rather than guessing the bytes by hand. `scripts/` holds decoders for several schemes (each script's header says which one it handles), and the per-scheme key constants live in the params file (`parameters.txt`), one row per scheme. The scripts do not hard-code those constants — pass them on the command line. A blob decodes cleanly under exactly one scheme: the right script and row print readable text, while every other combination runs without error but prints garbage. If you don't already know the scheme, work through the rows and keep the output that reads as plain language. The hex decoder runs as: ``` perl /skills/cipher-decoder/scripts/decode.pl --mult <m> --add <a> <hex-ciphertext> ``` The decoder prints the plaintext to stdout (no trailing newline).