BBMTLib

Bold Bitcoin MPC TSS Library

A secure Multi-Party Computation (MPC) Threshold Signature Scheme (TSS) library for Bitcoin, built for mobile integration on both iOS and Android.

NOSTR Integration for Wallet Creation and Transactions

BBMTLib now leverages NOSTR relays to create wallets and send transactions, utilizing a robust multi-layer encryption pattern based on Nostr Improvement Proposals (NIPs):

• NIP-44: Encrypted Direct Messages using shared secret derivation
• NIP-59: Gift Wraps (Rumor → Seal → Wrap pattern for TSS message transport) to enhance privacy

Key Security Benefits:

• End-to-end encryption between parties
• Metadata privacy (relays cannot see sender/recipient relationships)
• Forward secrecy (one-time keys for wraps)
• Authentication (signed seals verify sender identity)

CLI Usage Option

In addition to library integration for mobile apps, BBMTLib also provides a command-line interface (CLI) for testing and automation. This allows developers to generate wallets, sign transactions, and interact with NOSTR relays directly from the terminal. See the cmd/ directory and included examples for CLI usage instructions.

How to Build

# Get dependencies
go mod tidy

# Initialize Go Mobile (install as tool, doesn't modify go.mod)
go install golang.org/x/mobile/bind@latest

# Set build flags
export GOFLAGS="-mod=mod"

iOS

# Build for iOS, macOS, and iOS Simulator
gomobile bind -v -target=ios,macos,iossimulator -tags=ios,macos,iossimulator github.com/BoldBitcoinWallet/BBMTLib/tss

Android

# Build for Android
gomobile bind -v -target=android github.com/BoldBitcoinWallet/BBMTLib/tss

# If the following error occurs  
"no usable NDK in /Android/Sdk: unsupported API version 16"
# Then specify the version api with the following command
gomobile bind -v -target=android -androidapi 21 github.com/BoldBitcoinWallet/BBMTLib/tss

# Copy the generated tss.aar lib to the android/app/libs folder
cp tss.aar ../android/app/libs/tss.aar

License

This project is licensed under the Apache-2.0 License. See LICENSE for details.

NOTICE

This product includes modified code from third-party projects. For full attribution details, see the NOTICE file.