https://github.com/le0developer/jspowobfdata
JavaScript Proof Of Work Obfuscated Data
https://github.com/le0developer/jspowobfdata
Last synced: about 1 month ago
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JavaScript Proof Of Work Obfuscated Data
- Host: GitHub
- URL: https://github.com/le0developer/jspowobfdata
- Owner: Le0Developer
- License: mit
- Created: 2025-12-29T13:30:25.000Z (2 months ago)
- Default Branch: master
- Last Pushed: 2026-01-08T15:06:41.000Z (about 2 months ago)
- Last Synced: 2026-01-08T17:27:16.038Z (about 2 months ago)
- Language: Rust
- Homepage: https://le0developer.github.io/jspowobfdata/
- Size: 190 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# jspowobfdata
JavaScript Proof Of Work Obfuscated Data.
This project provides a way to obfuscate data using a proof-of-work mechanism in
JavaScript. The obfuscated data can only be deobfuscated by solving a
computational puzzle, ensuring that the data is protected until the
proof-of-work is completed.
This is useful for scenarios where you want to hide information from casual bots
or automated systems, requiring them to expend computational effort before
accessing the data (for example, contact information on a webpage).
## Usage
Use the website to obfuscate your data:
https://le0developer.github.io/jspowobfdata/index.html
## Compatibility
The script used at runtime to deobfuscate is approximately:
| Minified | Gzipped | Brotli |
| -------- | ------- | ------ |
| 1258 B | 705 B | 607 B |
It works in all modern browsers that support the
[Web Crypto API](https://caniuse.com/mdn-api_subtlecrypto) (Widely available
since 2017).
## Modern build
If you can spare some extra bytes and want better performance, you can use the
modern build that uses WebAssembly and Web Workers. This build is around:
| Minified | Gzipped | Brotli |
| -------- | ------- | ------ |
| 16966 B | 7444 B | 6463 B |
To use the modern build, include the `MODERN=1` flag when building the library
with `make`. The WASM implementation is ~5-6x faster than the pure SubtleCrypto
implementation.
If WASM or Workers are not supported, it will gracefully fall back to the pure
SubtleCrypto implementation (however without yielding to the main event loop due
to build flags).
## Animation
The `aria-busy` attribute is used to indicate the deobfuscation process is
ongoing. This allows you to add CSS animations during the proof-of-work phase.
We use such an animation (provided by [Pico.css](https://picocss.com/) ) on our
[demo page](https://le0developer.github.io/jspowobfdata/demo.html).
## Details
The obfuscation process involves the following steps:
1. Choose a key space (in bits) that determines the difficulty of the
proof-of-work.
2. Generate a 32-byte AES-GCM key and a random nonce.
3. Encrypt the data using AES-GCM with the generated key and nonce.
4. Blank out N bits of the key to create a puzzle. The number of bits to blank
is determined by the chosen key space.
5. Package the obfuscated data, nonce, and puzzle.
## Extra libraries
There are some extra libraries available in this repo, but you need to clone and
build them yourself using `make all`. They will be in the `dist/` folder after
building.
- `main.js` - The main runtime script to deobfuscate data in the browser. (see
table above for size)
- `page.js` - The runtime script for the demo page. Almost 4kb due to UI
handling, generation and speedtest. You shouldn't need to ever use this.
- `weblib.js` - This has the runtime logic like `main.js`, but it only exposes a
minimal Javascript API and doesn't interact with the DOM by default. This
makes it a further ~300 bytes smaller than `main.js`. By default it exports as
a global `jsobfpow` function, but you can change that with build time flags.
See `src/bundles/weblib.sk` for details.
## References
This is inspired by
[Altcha's Obfuscating Data](https://altcha.org/docs/v2/obfuscation/) feature,
however this implementation has a few key differences:
- No branding
- Small footprint (>25 times less JavaScript shipped to the client)
## Contributing
I consider this project in its current form to be feature complete.
Measurable improvements (e.g. runtime code size) will be welcome.