TG

Trezor Guardian — Advanced Security Guide

Practical advice for power users and integrators: seed hygiene, multisig, air-gapped workflows, and incident response.

Trezor devices are designed around a simple promise: private keys are generated, stored, and used within a trusted device that you control. This guide expands beyond basics to provide actionable, engineering-friendly recommendations for dramatically reducing compromise risk across personal and organizational deployments.

Seed and recovery best practices

Your recovery seed is the single most critical asset. Treat it as more sensitive than any password or cloud credential.

Generate offline
Prefer device-generated seeds. If remotely generated seeds are unavoidable, reseed into a trusted air-gapped device and verify public addresses.
Physical backups
Use metal seed plates or split the seed (Shamir/secret sharing) across geographically separated, tamper-evident storage.
Passphrase layer
Add an optional passphrase for plausible deniability and hidden wallets; ensure passphrase entry is never recorded by hosts.
Never store digitally
Avoid photos, cloud notes, or password managers for seed material. If you must store electronically, encrypt with a strong key and offline storage.

Advanced signing workflows

Air-gapped signing and multisignature policies substantially raise the bar for attackers.

  • Use unsigned transaction construction on an online host, then transfer the payload to an air-gapped Trezor (SD/QR) for signing.
  • Design multisig with geographically and administratively separated cosigners; prefer 2-of-3 or higher for custody.
  • Automate audit logs: record transaction preimage hashes and device confirmations in a write-only log for incident investigation.

Integration and developer tips

Treat hardware wallets as signing modules. Minimize host logic and validate everything you receive back from the device.

  1. Canonical serialization: use deterministic serialization for all signed payloads to prevent malleability.
  2. Bind context: include chain/network IDs and nonces inside signing payloads to avoid replay across chains.
  3. Rate-limiting: host-side rate limits and exponential backoff reduce the surface for host-driven DoS against the device.

Incident response playbook

Prepare for compromise with a clear, tested plan.

  • If seed is suspected compromised: generate a fresh seed on a new device, rotate funds to new addresses, and revoke any online access tokens.
  • For lost device (not seed): restore the seed to a new device and rotate any exposed public keys where possible.
  • Document and timestamp all actions; for organizational incidents, involve legal and forensics early.
// Example: deterministic signing payload (JSON-LD like pseudocode)
{
  "@context":"https://trezor.example/tx",
  "network":"bitcoin-mainnet",
  "inputs":[...],
  "outputs":[...],
  "metadata":{"nonce":""}
}

Accessibility & audits

Auditability is core: Trezor's firmware and tooling are open-source, enabling independent review. Encourage third-party audits and keep supply chains transparent when procuring devices at scale.