Opendime Pubkey Calculator

This tool calculates the public key of any sealed Opendime based on the contents of its advanced/verify2.txt file.

You can use the tool here or you can run it locally on your computer.

How to set up locally:

• Clone this repository.

• Run npm install to install the dependencies, including Browserify.

• Run browserify app.js -o opendime-pubkey.js to compile the Javascript file to be used in the browser.

• Open opendime-pubkey.html in your browser to use.

How to use in the browser:

• Plug in your sealed Opendime. There is no need to reveal the private key for this to work.

• Navigate to the advanced folder and find verify2.txt. Copy the contents into the text area.

• Click on the Calculate Public Key button; you should see your Opendime's public key.

• Optional: Click on the Copy to clipboard button to copy the public key. An alert will appear if successful.

Motivation:

Opendime devices have a unique property that allow ownership of a private key without knowledge of it. Opendimes are also much cheaper than hardware cryptocurrency wallets. Finally, revealing the private key requires irreversible physical tampering (destruction).

I believe these qualities give the Opendime potential to be used as a physical access key, e.g. a physical multisig key. Since the complex issue of cybersecurity is reduced to the simple issue of physical security, storage is much more operationally simple than most other options such as a raw private key, encrypted private key, paper wallet, seed phrase, etc.

Disclaimer:

Use at your own risk. I will not be held accountable for any bugs or errors.

Most of the code in app.js is directly copied from bitcoinjs-message. I would like to thank the developers who made this library.