When Internet Is Not Required

  • Device Communication:
    Bridge simply allows your computer to talk to your Trezor via USB. This communication happens locally over 127.0.0.1 (localhost).
  • Offline Transaction Signing:
    You can prepare a transaction on an offline computer, sign it with your Trezor, and export the signed transaction without internet access.
  • Accessing Stored Keys:
    Since Trezor never exposes your private keys, you can still use it offline to verify addresses or sign messages.

When Internet Is Required

  • Fetching Blockchain Data:
    Wallet interfaces like Trezor Suite or MetaMask need internet access to retrieve account balances, transaction history, or network fees.
  • Firmware & Software Updates:
    Installing Trezor Bridge updates or Trezor firmware updates requires downloading files from the internet.
  • Connecting to Browser Wallets or DApps:
    If you want to interact with DeFi apps or exchanges via your Trezor, an internet connection is necessary (but the Bridge itself still runs locally).

Key Takeaway

You can run Trezor Bridge entirely offline, but the applications using it may need internet to function fully. For highly secure setups (e.g., air-gapped systems), you can prepare transactions on an online device and sign them offline with Trezor + Bridge.

Is Trezor Bridge Safe?

Trezor Bridge runs locally on your computer and does not transmit private keys or sensitive information over the internet. Your Trezor device always signs transactions internally, ensuring that private keys never leave the hardware wallet. The main security risks arise from user-side mistakes or malware, not the Bridge itself.

Security Risks to Avoid

1. Downloading From Unofficial Sources

  • Risk: Fake websites may distribute compromised versions of Trezor Bridge.
  • Solution: Always download from the official Trezor website (trezor.io/bridge).

2. Outdated Bridge Versions

  • Risk: Older versions may contain bugs or lack compatibility with newer security protocols.
  • Solution: Keep Bridge updated by regularly checking the official site.

3. Malicious Browser Extensions

  • Risk: Some rogue browser extensions can attempt to intercept or spoof communication between your browser and Bridge.
  • Solution: Use a clean browser profile and avoid unnecessary crypto-related extensions.

4. Malware on Your Computer

  • Risk: Keyloggers or screen-capturing malware could target Trezor Suite or browser wallet interactions.
  • Solution: Keep your OS updated, run antivirus scans, and consider using Trezor on a dedicated or clean device.

5. Fake Transaction Prompts

  • Risk: Phishing attacks may trick you into approving a malicious transaction that appears legitimate on your screen.
  • Solution: Always verify transaction details directly on the Trezor device screen before confirming.

Best Security Practices

  • Verify Downloads: Check file hashes or signatures provided by Trezor.
  • Use a Strong PIN and Passphrase: Even if your device is stolen, your crypto remains safe.
  • Disconnect When Not in Use: Unplug your Trezor device when you’re not making transactions.
  • Be Aware of Remote Attacks: Avoid running Bridge on devices exposed to unknown or risky networks.

Key Takeaway

Trezor Bridge itself is secure, but your overall safety depends on maintaining a clean environment, verifying sources, and practicing good operational security. Remember: Your Trezor device is your last line of defense—always confirm actions on the hardware screen.