bc-lifehash is a method of hash visualization based on Conway's Game of Life that creates beautiful icons that are deterministic, yet distinct and unique given the input data.
The basic concept is to take a SHA-256 hash of the input data (which can be any data including another hash) and then use the 256-bit digest as a 16x16 pixel "seed" for running the cellular automata known as Conway's Game of Life. After the pattern becomes stable (or begins repeating) the resulting history is used to compile a grayscale image of all the states from the first to last generation. Using Game of Life provides visual structure to the resulting image, even though it was seeded with entropy. Some bits of the initial hash are then used to deterministically apply symmetry and color to the icon to add beauty and quick recognizability.
This is the first-party Rust implementation. It produces byte-identical output to the C++ reference implementation, validated against 35 test vectors covering all five versions.
See a LifeHash demo at LifeHash.info.
[dependencies]
bc-lifehash = "0.1.0"Five LifeHash versions are supported:
- Version1 / Version2 — 16x16 grid, up to 150 generations.
- Detailed — 32x32 grid, up to 300 generations, richer color gradients.
- Fiducial — 32x32, designed for use as fiducial markers.
- GrayscaleFiducial — Same as Fiducial but rendered in grayscale.
// Generate a LifeHash image from a UTF-8 string
let image = bc_lifehash::make_from_utf8("Hello", bc_lifehash::Version::Version2, 1, false);
assert_eq!(image.width, 32);
assert_eq!(image.height, 32);
// image.colors contains packed RGB bytes (width * height * 3)You can also generate from raw bytes or a pre-computed 32-byte SHA-256 digest:
let image = bc_lifehash::make_from_data(&[0x01, 0x02, 0x03], bc_lifehash::Version::Detailed, 1, false);
// Or from a digest directly (must be exactly 32 bytes)
let digest = [0u8; 32];
let image = bc_lifehash::make_from_digest(&digest, bc_lifehash::Version::Fiducial, 1, true);
// With has_alpha=true, image.colors contains RGBA bytes (width * height * 4)| Type | Name | Language | Note |
|---|---|---|---|
| Reference | bc-lifehash | C++/C | |
| First-Party | bc-lifehash-rust | Rust | This crate |
| Third-Party | lifehash-rs | Rust | Galactechs LLC |
| Third-Party | bc-lifehash-python | Python | Cramium |
| Third-Party | toucan | Java | Sparrow Wallet |
| Reference | LifeHash | Swift |
- 0.1.0, March 16, 2026
- Initial release of bc-lifehash crate.
- LifeHash visual hashing algorithm based on Conway's Game of Life.
- Supports five versions: Version1, Version2, Detailed, Fiducial, GrayscaleFiducial.
- Deterministic SHA-256-seeded cellular automata with symmetry and color transforms.
- Configurable module size and optional alpha channel output.
- Test vectors and PNG generation tests.
- Byte-identical output to the C++ reference implementation.
bc-lifehash is currently in a community review stage. We would appreciate your consideration and/or testing of the libraries. Obviously, let us know if you find any mistakes or problems. But also let us know if the API meets your needs, if the functionality is easy to use, if the usage of Rust feels properly standardized, and if the library solves any problems you are encountering when doing this kind of coding. Also let us know how it could be improved and what else you'd need for this to be just right for your usage. Comments can be posted to the Gordian Developer Community.
Because this library is still in a community review stage, it should not be used for production tasks until it has had further testing and auditing.
See Blockchain Commons' Development Phases.
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| Name | Role | Github | GPG Fingerprint | |
|---|---|---|---|---|
| Christopher Allen | Principal Architect | @ChristopherA | <ChristopherA@LifeWithAlacrity.com> | FDFE 14A5 4ECB 30FC 5D22 74EF F8D3 6C91 3574 05ED |
| Wolf McNally | Lead Researcher/Engineer | @WolfMcNally | <Wolf@WolfMcNally.com> | 9436 52EE 3844 1760 C3DC 3536 4B6C 2FCF 8947 80AE |
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Please report suspected security vulnerabilities in private via email to ChristopherA@BlockchainCommons.com (do not use this email for support). Please do NOT create publicly viewable issues for suspected security vulnerabilities.
The following keys may be used to communicate sensitive information to developers:
| Name | Fingerprint |
|---|---|
| Christopher Allen | FDFE 14A5 4ECB 30FC 5D22 74EF F8D3 6C91 3574 05ED |
You can import a key by running the following command with that individual's fingerprint: gpg --recv-keys "<fingerprint>" Ensure that you put quotes around fingerprints that contain spaces.