Hardware Signing Device Guide
Hardware signing devices are essential for secure Bitcoin storage in collaborative security setups. This guide explains what they are, why Trezor is recommended, and how to set them up safely for use with your 2/3 multisig vault.
What Is a Hardware Signing Device?
A hardware signing device (often called a hardware wallet) is a physical device that stores your private keys offline and approves Bitcoin transactions. In collaborative security, it provides your approval after you initiate a transaction. One additional approval is still required before Bitcoin can move.
Unlike software wallets that store keys on your computer or phone, hardware signing devices keep your keys isolated from internet-connected devices, making them much harder to compromise.
See our Buy Bitcoin Resources page for recommended Trezor models with images and direct purchase links.
Why "Signing Device" Not "Wallet"?
In collaborative security, we use the term "hardware signing device" because it more accurately describes the device’s role. The device doesn’t store your Bitcoin, it signs transactions. Your Bitcoin is secured by the multisig vault structure, with the hardware device providing one of the required signatures.
A signing device is not the custody plan
A hardware signing device is an important security layer, but it should not be treated as infallible.
Device security issues can affect hardware, firmware, seed generation, backups or the software used to coordinate transactions.
In collaborative security, the device protects one key inside a wider multisig structure. A failure involving that device or key cannot, by itself, move the Bitcoin. See also our current Coldcard hack warning and the evergreen Hardware Wallet Security guide.
Why We Recommend Trezor
Trezor is our recommended hardware signing device for several key reasons:
Ease of Use
Trezor devices are straightforward to set up and use, making them ideal for clients new to hardware signing devices. The interface is intuitive and well-documented.
Security model and transparency
Trezor has a long operating history and publishes open-source firmware that can be reviewed by security researchers. No hardware device should be treated as immune from future vulnerabilities, so device choice must sit inside a broader custody and recovery structure.
Multisig Support
Trezor devices work seamlessly with Theya and Unchained vault providers, making them perfect for collaborative security setups.
Cost-Effective
Trezor offers excellent value for money, with models available at different price points to suit various needs and budgets.
Already have a hardware device? Existing compatible devices may be used after their model, firmware, setup history and any current security warnings are reviewed during onboarding. Trezor remains our recommended choice for new purchases. Current Coldcard owners should review the Coldcard hack warning before retaining or admitting a key.
Alternative Options
While Trezor is recommended, there are alternatives depending on your needs:
Software Key with Theya (iOS Only)
If you use an iPhone, you can use Theya’s software key option instead of a hardware device. This provides convenience while still maintaining the security benefits of 2/3 multisig. The software key runs on your iPhone and integrates directly with the Theya app.
When to choose this: If you prefer not to manage a physical device and you’re comfortable with iOS-based security. The multisig structure still provides strong protection even with a software key.
Other Hardware Devices
Existing compatible devices may be used after their model, firmware, setup history and any current security warnings are reviewed during onboarding. Compatibility with Theya or Unchained is necessary but not sufficient.
During onboarding we record device provenance (brand and model, firmware at initialisation, seed-generation date and method, passphrase policy, wallet fingerprint, vault role and applicable security notices). Seed material is never placed in the Estate Plan Protocol.
Note: For new purchases, we recommend Trezor for ease of use, open firmware reviewability and strong multisig support inside a broader custody structure.
How to Choose a Trezor Model
We recommend two Trezor models for collaborative security setups:
Trezor Safe 3
Our default hardware signer, simple, secure, and straightforward to recover in collaborative vaults. Perfect for most clients.
Trezor Safe 5
Latest-gen flagship with enhanced secure element, ideal for signers handling significant value or wanting premium features.
Both models work seamlessly with Theya and Unchained vault providers. For most clients, Trezor Safe 3 provides the best balance of security, features, and value.
Where to buy: See our Buy Bitcoin Resources page for direct links to purchase Trezor Safe 3 and Safe 5. You can also purchase directly from Trezor or reputable resellers. Avoid buying from third-party marketplaces where devices could be tampered with.
Setup and Security Best Practices
Proper setup is critical for security. Follow these steps:
Initial Setup Steps
- Purchase from official source: Buy directly from Trezor or authorized resellers
- Verify packaging: Check that the device packaging is sealed and untampered
- Follow official setup guide: Use Trezor’s step-by-step guides:
- Install Bitcoin-only firmware: During setup, choose Bitcoin-only firmware instead of the multi-coin version. This reduces the attack surface by removing support for other cryptocurrencies, making your device more secure and focused on Bitcoin.
- Initialize the device: Set up a new wallet (never use a pre-configured device)
- Write down your recovery seed: This is your backup if the device is lost or damaged
- Test the recovery process: Verify you can restore from your seed phrase
- Set a PIN: Choose a strong PIN to protect the device
The official Trezor guides cover firmware installation, wallet creation, backup & recovery in detail. We recommend following them step-by-step, and your adviser can help during onboarding if you have questions.
Never share your recovery seed phrase with anyone. Not with us, not with support, not with anyone. The seed phrase is your backup, if someone else has it, they can access your keys. Store it securely offline.
Security Best Practices
- Use Bitcoin-only firmware: Install and maintain Bitcoin-only firmware on your Trezor device. This reduces the attack surface and keeps your device focused on Bitcoin security.
- Store your recovery seed securely: Use a metal backup or store in a fireproof safe. Never store it digitally or in the cloud.
- Keep your device firmware updated: Regular updates include security improvements. When updating, ensure you maintain Bitcoin-only firmware. Updating firmware may correct new seed generation or signing behaviour without changing a seed that already exists. Read the vendor’s official notice to determine whether key replacement or wallet migration is also required.
- Use a strong PIN: Choose a PIN that’s hard to guess but easy for you to remember
- Keep the device physically secure: Store it in a safe place when not in use
- Verify addresses on the device: Always confirm receiving addresses on the device screen, not just on your computer
- Never enter your seed phrase online: Legitimate services will never ask for your seed phrase
Integration with Collaborative Security
During onboarding, we’ll help you integrate your hardware signing device with your Theya or Unchained vault:
The Integration Process
- Device connection: Connect your Trezor to your computer during the onboarding call
- Vault setup: Your adviser guides you through connecting the device to your vault
- Key generation: The device generates one of your three multisig keys
- Verification: We verify the setup and test a small transaction
- Documentation: The device configuration is documented in your Estate Plan Protocol
The entire process takes about 15 minutes during your onboarding call. Your adviser is there to guide you every step of the way.
You don’t need to buy hardware through us. Purchase directly from Trezor or reputable resellers. We’ll help you configure whatever device you choose during onboarding.
Backup and Recovery
If your hardware signing device is lost, stolen, or damaged, you can recover access using your recovery seed phrase:
Recovery Process
- Purchase a replacement device: Any Trezor device (or compatible hardware) will work
- Restore from seed phrase: Use the recovery seed phrase you wrote down during initial setup
- Reconnect to vault: Your adviser helps you reconnect the restored device to your vault
- Verify access: Test that you can sign transactions with the restored device
Important: Losing your hardware device does not by itself freeze collaborative vault funds. You initiate transactions; the hardware device provides your approval; one more approval is still required. Contact your adviser before you act. How signing works →
Store your recovery seed phrase securely. Consider using a metal backup for fire and water protection. Store it in a location separate from your device. Never store it digitally or share it with anyone.
Common Mistakes to Avoid
Avoid these common pitfalls when using hardware signing devices:
❌ Buying from Untrusted Sources
Only buy from Trezor directly or authorized resellers. Third-party marketplaces may sell tampered devices.
❌ Using a Pre-Configured Device
Always initialize a new device yourself. Never use a device that comes with a seed phrase already set up.
❌ Storing Seed Phrase Digitally
Never take photos, store in cloud storage, or type your seed phrase into any device. Write it down on paper or metal.
❌ Sharing Your Seed Phrase
No legitimate service will ever ask for your seed phrase. Never share it with anyone, including support staff.
❌ Not Testing Recovery
Test that you can restore from your seed phrase before storing significant funds. Practice makes perfect.
❌ Ignoring Firmware Updates
Keep your device firmware updated. Updates often include important security improvements. A firmware fix may still leave an existing seed needing migration. Read the vendor notice.
How The Bitcoin Adviser Helps
We provide comprehensive support for hardware signing device setup and management:
- Guidance on device selection: We help you choose the right device for your needs
- Setup assistance: Your adviser guides you through device setup during onboarding
- Vault integration: We help you connect your device to your Theya or Unchained vault
- Recovery support: If your device is lost or damaged, we help you restore access
- Ongoing assistance: Questions about your device? Your adviser is always available
- Documentation: Device details are included in your Estate Plan Protocol for your heirs
You’re never alone. From choosing a device to setting it up to recovering from loss, your dedicated Bitcoin Adviser is here to help every step of the way.
Get Help with Hardware Setup
Clients can book meetings with their advisers for hardware device setup, configuration, or troubleshooting. Whether you’re choosing your first device, setting up a replacement, or have questions about your current setup, your dedicated Bitcoin Adviser is here to help.
Already a client? Reach out to your adviser directly to schedule a session.
Not yet a client? Book a consultation to learn how we can help.
Educational only: no financial, tax, or legal advice. Seek appropriate licensed professionals where required. Device recommendations are based on our experience and may not suit all users.