Tendermint KMS

Using Tendermint KMS for BitNet Validator Security

Tendermint KMS (Key Management System) allows BitNet validators to separate key management from their core nodes. It improves validator security by protecting keys against compromise, reducing the risk of double-signing, and supporting hardware security modules (HSMs) such as Ledger or YubiHSM.

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Benefits of Tendermint KMS

• Hardware or software-based double-signing protection

• Support for secure devices (e.g., Ledger, YubiHSM 2)

• Defense-in-depth through physical separation of the signing process

• Secure centralized key signing across multiple validators or BitNet zones

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Prerequisites for Installing KMS

Install the following dependencies:

# Debian/Ubuntu
sudo apt install libusb-1.0-0-dev pkg-config build-essential

# RedHat/CentOS
sudo yum install libusb1-devel

# macOS
brew install libusb

Install Rust:

curl https://sh.rustup.rs -sSf | sh

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Compiling Tendermint KMS from Source

Clone the repository and build the binary:

git clone https://github.com/iqlusioninc/tmkms && cd tmkms
cargo build --release --features=ledger

For YubiHSM support, replace --features=ledger with --features=yubihsm.

This creates the tmkms binary at:

./target/release/tmkms

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KMS Configuration with Ledger Devices

Ledger requirements:

• Ledger Nano X or S

• Ledger Live installed

• Tendermint Validator App (Developer Mode)

Enable Developer Mode in Ledger Live and install the Tendermint App.

Create a config file:

# ~/.tmkms/tmkms.toml
[[validator]]
addr = "tcp://localhost:26658"
chain_id = "bitnet-mainnet"
reconnect = true

[[providers.ledger]]
chain_ids = ["bitnet-mainnet"]

Start the key manager:

tmkms keygen ~/.tmkms/secret_connection.key
tmkms start -c ~/.tmkms/tmkms.toml

The validator key will appear in the logs (e.g. bitnetvalconspub...). Save this for the next step.

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Connecting BitNet Node to KMS

Edit config.toml in your BitNet node to enable external key signing:

priv_validator_laddr = "tcp://127.0.0.1:26658"

Start your BitNet validator node:

bitnetd start

Once launched, the Ledger device will request confirmation before signing messages. If confirmed, the KMS will automatically handle signature requests securely.

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Final Note on KMS Security

• These instructions serve as a starter guide. For production, validators must fully evaluate the security implications of KMS usage.

• The "TEST" message on the Ledger device screen is shown only in pre-release firmware. It should not appear once the Tendermint app is officially published.