🔓 Xiaoxiao Decrypt (潇潇图片解混淆)

XiaoxiaoDecrypt (displayed as "🔓 Xiaoxiao Decrypt (潇潇图片解混淆)") is the other half of the obfuscation pair in ComfyUI-FastTool. If you've ever opened a folder of PNGs that look like static noise and wondered who broke your images - that's this family. The encrypt node scrambles pixel positions along a space-filling curve using a password as the shuffle seed; this node applies the inverse permutation and puts the pixels back. Same password, same dimensions, picture restored.

The "解混淆" in the display name is the honest word: this de-obfuscates, it doesn't "decrypt" in the cryptographic sense. The mechanism is a deterministic pixel reorder, so it's fast (no expensive crypto), fully reversible, and utterly dependent on you getting two things right: the password and the image dimensions. There's no key to manage, no nonce, no integrity check - which is also exactly why it can't tell you the password is wrong. Give it the wrong string and it happily produces confident, scrambled-looking static.

When you'd reach for it

Three cases, basically. Someone shared an obfuscated preview (challenge thumbnails, teasers) and you have the password. You encrypted a batch of your own WIPs and want them back. Or you're building a workflow where a generation gets scrambled mid-graph (say, a preview stage) and needs unscrambling before it goes to a SaveImage. The node runs as a standard graph node, so it slots into any of those.

Inputs and outputs

• image (optional) or input_folder (optional) - decrypt whatever's flowing through the graph, or point at a folder of PNGs/JPGs/WebPs for batch mode. Folder mode uses a thread pool (max_workers, default 4) and writes dec_<name>.png files.
• password - must match the one used to encrypt. Empty works only if the encrypt side also used an empty password (a fixed, password-less shuffle - the worst of all worlds, don't).
• output_folder (default output_xiaoxiao) - where the restored PNGs land, relative to your ComfyUI root.
• strip_metadata (default true) - on the decrypt side this just controls whether any metadata that survived the obfuscated file is carried into the restored PNG. Since obfuscation normally stripped it, this rarely matters; but if you kept an original with metadata and round-tripped it, note that ComfyUI-style workflow metadata will not come back from a metadata-less file.
• max_preview (default 4) - the node returns the last max_preview restored images as its output batch.

Output is a single image - the restored batch - plus the files on disk.

Install

Part of ComfyUI-FastTool; one install covers the whole pack:

cd ComfyUI/custom_nodes
git clone https://github.com/Fengxiaoxiao-001/ComfyUI-FastTool.git

Or ComfyUI Manager (search "FastTool"), then restart. No pip dependencies - it's pure numpy/torch/Pillow.

Where people get burned

• Same dimensions, always. The shuffle is derived from the image's width and height at encrypt time. An image encrypted at 1024×1024 will not decrypt correctly at 512×512 - you'll get noise, silently. Resize back to the original before decrypting.
• Wrong password gives no warning. Test with a single image and a known-good password before burning a whole folder through it. The node can't detect a mismatch.
• Lost metadata stays lost. If the obfuscated PNG had its workflow metadata stripped (the default), decrypting won't conjure it back. Keep the originals if you'll ever need the generation settings.
• It's reversible by anyone with the source. The algorithm ships in the pack. Treat this pair as spoiler-prevention, not security - and never base a real password on something you care about.