Trézór Bridge®™ — Secure Crypto Connectivity

What is the Trézór Bridge concept?

In simple terms, a “bridge” is a small, trusted helper application that runs on your computer (or as part of a desktop manager) and lets web pages and decentralized apps (dApps) talk to a hardware wallet connected to that computer. The bridge relays requests — like “show me addresses” or “sign this transaction” — and ensures the sensitive private keys remain inside the hardware device.

Bridges exist because web browsers and OSs have limitations and security policies that prevent direct, consistent access to USB/BLE devices across platforms. A well-implemented bridge preserves the device’s security model while improving web3 usability.

Why a bridge matters for security and compatibility

• Key isolation: Your private keys never leave the hardware wallet — the bridge only forwards signing requests.
• Cross-platform support: Bridges enable consistent behavior across browsers and operating systems that might not support direct hardware access.
• On-device confirmations: The hardware wallet shows transaction details and requires physical confirmation — the bridge cannot sign without this step.

Before you install: a safety checklist

• Buy hardware wallets from authorized sellers; avoid used or tampered devices.
• Type vendor domains directly into the browser — don’t click emailed or social links.
• Prepare offline backups for your recovery seed (paper and/or metal backup plate).
• Consider a dedicated browser profile for dApps to reduce extension or cookie cross-contamination.

Installing and running the bridge (practical steps)

1. Download the official package: Go to the vendor’s verified download page and grab the bridge or manager app installer. Prefer HTTPS and check signatures if the vendor publishes them.
2. Verify integrity: If checksums or PGP signatures are available, verify the file before installation to ensure authenticity.
3. Install and allow permissions: Run the installer and grant only the permissions required (USB access, local loopback). Avoid forked or unknown binaries.
4. Start the bridge: Confirm the bridge is running in your system tray or background services before connecting your hardware wallet.
5. Connect your wallet: Plug in the device and unlock it with your PIN — always enter the PIN on the device itself.

Typical user workflows

Receiving crypto

1. Open your wallet manager or dApp and select the account to receive into.
2. Generate a receiving address and verify the same address on the hardware device screen.
3. Share that address with the sender or enter it into the sending platform.

Sending crypto

1. Create a transaction in your app.
2. The bridge forwards the request; the device displays recipient, amount, and fees.
3. Verify every detail on the device display. If anything differs from the app, cancel.
4. Confirm on-device to sign; the bridge returns the signed transaction for broadcast.

Interacting with smart contracts

Smart-contract interactions may show limited information on-device depending on vendor support. Prefer dApps that present decoded summaries and use minimal allowance approvals. For high-risk actions, verify contract code using trusted explorers or interfaces.

Security best practices — quick reference

• Verify downloads and signatures before installing a bridge or manager app.
• Confirm addresses, amounts, and contract data on the device screen every time.
• Use a dedicated, minimal browser profile for web3; avoid unnecessary extensions.
• Keep firmware, bridge software, and dApp dependencies up to date via official channels.
• Limit broad approvals (give contracts the smallest allowance necessary) and revoke unused allowances.
• Consider metal seed backups for fire/water resistance for long-term custody.

Troubleshooting common problems

Bridge not running or not detected

• Check system tray / menu bar for the bridge process and restart it.
• Restart your browser or try a fresh browser profile without extensions.
• Try another USB cable or port (some cables are charge-only).

Transaction details differ on-device

Firmware compatibility warnings

• Only update firmware from the vendor’s official manager or website.
• If an update fails, consult official support before entering your recovery seed into anything — legitimate fixes will never require you to type your seed into a web form.

Developer guidance — integrate carefully

Developers building dApps that interface with a local bridge should prioritize clarity and safety:

• Never ask for or transmit seed phrases or private keys.
• Present a human-readable summary of transactions before invoking the bridge for signing.
• Prefer standard transports (WebHID/WebUSB) where supported and provide fallbacks for compatibility.
• Implement origin checks and show the origin to users where possible so it can be confirmed on-device or in bridge UI.
• Handle common error states (device locked, disconnected, firmware mismatch) gracefully and provide actionable remediation steps.

Advanced workflows

For highly sensitive operations consider air-gapped signing (export unsigned transaction, sign offline, import signed transaction for broadcast). For institutional or high-value custody, multisig setups and hardware security modules (HSMs) combined with audited orchestration software are recommended.

FAQ — short answers

Will the bridge ever ask for my recovery seed?

No. If any software asks for your seed, it is malicious — stop immediately and investigate.

Can I install the bridge on multiple machines?

Yes. Install the bridge only on machines you control and trust. Each installation must be verified like the first.

Is a bridge always required?

Not always. Modern browsers with WebHID/WebUSB can sometimes communicate directly, but a bridge improves compatibility and standardizes flows across browsers and OSs.