kdk

A WIP development kit in Rust for microcontroller bitcoin wallet signers (mainly aimed to ESP32 or STM32) based on selfcustody/krux and odudex/kern for support microcontroller hardware signers with rust.

Motivation

The motivation came from a past discussion that maybe could not be accesible based on past proposition to include nostr features on firmware (maybe could not be available for public and summarized here) as well personal shares with bitcoin/rust developer friends:

Should a hardware device support signing Nostr events? Definitely.

Should Krux? I think it could make sense (if you view Krux as firmware for hardware signing in general), but not in its current form due to all the Bitcoin-specific assumptions being made about wallets, receive addresses, PSBTs, etc.

The way I see it, there are 3 options:

1. Add support for Nostr in the existing UI, but wrap a bunch of places in if is_nostr() style checks to hide or show certain UI elements (e.g., Scan Address, Wallet, Sign PSBT, etc. don't make sense to show if using a Nostr key, and Show Nostr public key, Sign Nostr event don't make sense if using a Bitcoin key)
2. Fork Krux, rip out the Bitcoin stuff entirely, and focus the fork on being exclusively a Nostr signer
3. Don't fork Krux, but redesign it such that it can support different use cases or cryptocurrencies / elliptic curves.

What do others think?

Jeff Sun, Krux's creator

Disclaimer

In any way KDK wants to compete with Kern or Krux, neither to redesign some basic aspects of krux, almost following a mix of Option 1 and Option 3:

• keep based-bitcoin firwamre
• master branch could accept bitcoin-related PRs as features, except altcoins (i.e., nostr, liquid, pgp, crypto-primitives could be accepted depending o context and review) -- they could share traits, enums, structs and methods with different parameters (e.g: nostr and schnoor)

⚠️ Experimental. This software has not been audited. Do not use it with real funds. See SECURITY.md.

Quick start

Download

git clone https://github.com/qlrd/kdk.git

Rust unit tests

cargo test

Examples

To see sample examples:

cargo run --example <example_name> # on crates/kdk-*/examples

TODO

It's even have crates for microcontrollers, for now just some primitives to build with (rust-bitcoin/bdk if applicable) in future while waiting for microcontrollers come.

• wallet crate
• sign crate
• ...
• STM-32 crate
• ESP32-* crate
• integration tests (see bornal)

License

MIT — see LICENSE.