Beaufort Cipher

Beaufort is what you get when you take Vigenère and flip the subtraction around. Instead of cipher = plaintext + key, it computes cipher = key - plaintext. It's named after Sir Francis Beaufort (yes, the wind-scale guy - he had a varied career), and while it looks nearly identical to Vigenère, that one sign flip gives it a lovely property: encrypting and decrypting are the same operation. Run Beaufort encryption twice and you're back to your original text. That's a genuinely useful trait for a puzzle cipher, because it means a solver who figures out the decryption is literally just running the cipher again - and it's the trait that keeps Beaufort from being a mere curiosity.

The node itself is the pack's standard classical-cipher shape: text, alphabet, mode, and keep_formatting plus a key string (any text in the alphabet's language, empty by default). The mode toggle is still there for interface consistency, but as with Atbash, the math makes it nearly redundant - the key is what matters, not the direction. Output is the single encrypted_txt STRING.

The inputs that matter

• key - the keyword. With Beaufort, the same key encrypts and decrypts, which is one less thing to get wrong in a workflow. Just don't lose it.
• mode - present, harmless, mostly decorative. Flip it if you like; the result won't change.
• keep_formatting - the pack's spaces/punctuation/case toggle, worth remembering when comparing against reference tools.

Where people get burned

The main trap is expecting Beaufort to behave like Vigenère and assuming decryption needs a "reversed" key or mode. It doesn't. The second, more practical trap is key handling: the pack lowercases string keys in shared preprocessing, so if your reference tool is case-sensitive about the key, match its convention or you'll get output that "should" match but doesn't. And like every polyalphabetic cipher here, the round-trip is all-or-nothing - one character off in the key and decryption is instant garbage, no error message, no mercy.

Worth knowing before you build a puzzle around it: Beaufort is still a classical polyalphabetic substitution, so it's crackable with frequency analysis and known-plaintext work once the solver has enough ciphertext. It's a step up from Vigenère's repeating-key weakness only in the sense that it's less commonly attacked - not because it's fundamentally stronger. Use it for a satisfying mid-tier clue, not for anything that must stay secret.

Installing it

Standard pack install:

cd ComfyUI/custom_nodes
git clone https://github.com/AzelusLightvale/ComfyUI-ARG-Toolkit

Restart and find it under ARG Toolkit → Cryptography → Classical (ComfyUI Manager: search "ComfyUI ARG Toolkit"). Backed by secretpy, auto-installed by Manager or via pip install -r requirements.txt on manual clones. Pure Python, no models.

Troubleshooting

• Decrypt fails → key mismatch. Beaufort won't tell you nicely.
• Mode doesn't seem to do anything → correct, that's the symmetric property working as intended.
• Differs from an online tool → check formatting toggles and key case conventions.

Beaufort is the cipher for constructors who like elegant properties - the same key both ways is a neat detail to build a clue around ("the key unlocks both doors"). In a pack full of field ciphers and polyalphabetic classics, it's a quietly clever choice.