This program generates 3D printable key/data pairs that encrypt low res binary images.
The encryption is basically a One-time pad, with all its benefits and disatvantages (like being vulnurable to known plaintext attacks).
Each pixel is represented as a 2x2 grid of sub pixels, for each pixel exactly 2 sub pixels are "set".
First a key is generated by selecting a random arrangement of sub pixels.
If the pixel we are encrypt is "white" we simply copy the 4 sub pixels from the key, if it is "black" we invert them.
By overlaying the key sub pixels and the "encrypted" sub pixels we get either 2 white and 2 black subpixels (i.e. 50% gray) or 4 black subpixels (i.e. black) and thus can reconstruct the image:
encrypt_3d --key 42 --grid-width 8 --grid-height 8 --hole-ratio 0.2 generate-key --key-output example/small_key.stl
encodes an image, note that you MUST use the same key
encrypt_3d --key 42 --grid-width 8 --grid-height 8 --hole-ratio 0.2 encode --image-input example/line.png --image-output example/small_line.stl
number of holes on x axis
--grid-width
number of holes on y axis
--grid-height
size of holes (in range 0-1, as ratio to pixel size)
--hole-ratio
- create a virtual env
- install project editable:
pip install -e ".[dev]" - install commit hooks:
pre-commit install
pre-commit run --all-files
pre-commit run --all-files [HOOK_ID]
check .pre-commit-config.yaml for HOOK_ID
python -m build
wheels will be in dist folder
This was not my original idea, I stumbled across something similar done on overhead slides a couple of years ago, but I can't find the original source anymore.
If anyone has relevant references please sub mit a PR or open an issue.