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by Wolf McNally and Christopher Allen

LifeHashTool is a command line tool written in Swift that generates LifeHash images as PNG files.

LifeHashTool is distributed as a Swift package.

LifeHash Montage

Status - Late Alpha

LifeHashTool is currently under active development and in the late alpha testing phase. It should not be used for production tasks until it has had further testing and auditing.

Installation Instructions

git clone
cd LifeHashTool/

Build the Debug version:

swift build

Build the Release version:

swift build -c release

Build and install the release version as /usr/local/bin/lifehash:

Password: [enter your password]

⚠️ NOTE: To avoid having to code sign, the script does not copy the executable: it only creates a symbolic link to it. So if you delete the .build directory from the LifeHashTool directory, the link will no longer resolve.

⚠️ NOTE: As of the release of LifeHash 6, LifeHashTool generates .version2 LifeHashes by default.

Usage Instructions

Print the help:

lifehash --help

Usage: lifehash [OPTION...] [INPUT]

  -v VERSION      [version1|version2|detailed|fiducial|grayscaleFiducial] (default: version2)
  -m MODULE_SIZE  Size of each module ("pixel") (default: 1)
  -p OUTPUT_PATH  (default: current directory)

  -h --help       Print this message.

* The output PNG file will have the same name as the INPUT string.

* If no INPUT string is provided, a random one will be generated of the form "XXX-XXX" where X is a random letter.

Generate a version2, 32x32 pixel LifeHash in the current directory from the string "0":

lifehash 0


Generate a detailed, 64x64 pixel LifeHash in the current directory with a randomly generated name of the form "XXX-XXX" where X is a random letter.

lifehash -v detailed


Generate the same LifeHash as above, but use a module size of 8, resulting in a 512x512 image:

lifehash -v detailed -m 8 OKS-OID


Use the included script to generate 30 fiducial LifeHashes with a module size of 8 in the directory ./output:

./ fiducial 30 8

ls ./output

Use ImageMagick montage to create a montage of the images you just generated:

montage output/* montage.jpg
open montage.jpg

Origin, Authors, Copyright & Licenses

Unless otherwise noted (either in this / or in the file's header comments) the contents of this repository are Copyright © 2020 by Blockchain Commons, LLC, and are licensed under the spdx:BSD-2-Clause Plus Patent License.

In most cases, the authors, copyright, and license for each file reside in header comments in the source code. When it does not, we have attempted to attribute it accurately in the table below.

This table below also establishes provenance (repository of origin, permalink, and commit id) for files included from repositories that are outside of this repo. Contributors to these files are listed in the commit history for each repository, first with changes found in the commit history of this repo, then in changes in the commit history of their repo of their origin.

File From Commit Authors & Copyright (c) License
exception-to-the-rule.c or exception-folder 2020 Exception Author MIT


To build LifeHashTool you'll need to use the following tools:

  • Xtools with Swift (or another Swift compiler)

Derived from…

This LifeHashTool project is either derived from or was inspired by:

Used with…

These are other projects that work with or leverage LifeHashTool:

Financial Support

LifeHashTool is a project of Blockchain Commons. We are proudly a "not-for-profit" social benefit corporation committed to open source & open development. Our work is funded entirely by donations and collaborative partnerships with people like you. Every contribution will be spent on building open tools, technologies, and techniques that sustain and advance blockchain and internet security infrastructure and promote an open web.

To financially support further development of $projectname and other projects, please consider becoming a Patron of Blockchain Commons through ongoing monthly patronage as a GitHub Sponsor. You can also support Blockchain Commons with bitcoins at our BTCPay Server.

Project Sponsors

Thanks to our project sponsors for their support of $projectname:




We encourage public contributions through issues and pull requests! Please review for details on our development process. All contributions to this repository require a GPG signed Contributor License Agreement.


The best place to talk about Blockchain Commons and its projects is in our GitHub Discussions areas.

Gordian System Discussions. For users and developers of the Gordian system, including the Gordian Server, Bitcoin Standup technology, QuickConnect, and the Gordian Wallet. If you want to talk about our linked full-node and wallet technology, suggest new additions to our Bitcoin Standup standards, or discuss the implementation our standalone wallet, the Discussions area of the main Gordian repo is the place.

Wallet Standard Discussions. For standards and open-source developers who want to talk about wallet standards, please use the Discussions area of the Airgapped Signing repo. This is where you can talk about projects like our LetheKit and command line tools such as seedtool, both of which are intended to testbed wallet technologies, plus the libraries that we've built to support your own deployment of wallet technology such as bc-bip39, bc-slip39, bc-shamir, Sharded Secret Key Reconstruction, bc-ur, and the bc-crypto-base. If it's a wallet-focused technology or a more general discussion of wallet standards,discuss it here.

Blockchain Commons Discussions. For developers, interns, and patrons of Blockchain Commons, please use the discussions area of the Community repo to talk about general Blockchain Commons issues, the intern program, or topics other than the Gordian System or the wallet standards, each of which have their own discussion areas.

Other Questions & Problems

As an open-source, open-development community, Blockchain Commons does not have the resources to provide direct support of our projects. Please consider the discussions area as a locale where you might get answers to questions. Alternatively, please use this repository's issues feature. Unfortunately, we can not make any promises on response time.

If your company requires support to use our projects, please feel free to contact us directly about options. We may be able to offer you a contract for support from one of our contributors, or we might be able to point you to another entity who can offer the contractual support that you need.


The following people directly contributed to this repository. You can add your name here by getting involved. The first step is learning how to contribute from our documentation.

Name Role Github Email GPG Fingerprint
Christopher Allen Principal Architect @ChristopherA <> FDFE 14A5 4ECB 30FC 5D22 74EF F8D3 6C91 3574 05ED
Wolf McNally Project Lead @WolfMcNally <> 9436 52EE 3844 1760 C3DC  3536 4B6C 2FCF 8947 80AE

Responsible Disclosure

We want to keep all of our software safe for everyone. If you have discovered a security vulnerability, we appreciate your help in disclosing it to us in a responsible manner. We are unfortunately not able to offer bug bounties at this time.

We do ask that you offer us good faith and use best efforts not to leak information or harm any user, their data, or our developer community. Please give us a reasonable amount of time to fix the issue before you publish it. Do not defraud our users or us in the process of discovery. We promise not to bring legal action against researchers who point out a problem provided they do their best to follow the these guidelines.

Reporting a Vulnerability

Please report suspected security vulnerabilities in private via email to (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.


A command line tool written in Swift that generates LifeHash images as PNG files.



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