How do I enable USB-only mode on the Coldcard Mk4?

To enhance security, enable USB-only mode on your Coldcard Mk4 by navigating to Settings, selecting USB Mode, and choosing USB Only, limiting communication to USB.

Apr 04, 2025 at 05:49 am

Enabling USB-only mode on the Coldcard Mk4 is a crucial step for enhancing the security of your cryptocurrency transactions. This mode restricts the device to communicate only via USB, thereby reducing the risk of wireless attacks. To enable this feature, you will need to navigate through the Coldcard's menu system. Here's a detailed guide on how to do it:

Understanding USB-only Mode

USB-only mode on the Coldcard Mk4 ensures that the device can only be accessed through a USB connection. This is particularly useful for users who want to minimize the attack surface of their hardware wallet. By disabling other communication methods, you significantly reduce the chances of unauthorized access through Wi-Fi or Bluetooth. This mode is recommended for users who perform sensitive transactions and want to maintain the highest level of security.

Steps to Enable USB-only Mode

To enable USB-only mode on your Coldcard Mk4, follow these steps:

• Connect your Coldcard Mk4 to your computer using a USB cable.
• Power on the device and wait for the main menu to appear.
• Navigate to the "Settings" menu by pressing the arrow keys.
• Scroll down to "USB Mode" and select it.
• Choose "USB Only" from the list of options.
• Confirm your selection by pressing the OK button.

Once these steps are completed, your Coldcard Mk4 will operate in USB-only mode, ensuring that it can only be accessed through a USB connection.

Verifying USB-only Mode

After enabling USB-only mode, it's important to verify that the setting has been applied correctly. To do this:

• Disconnect and reconnect the Coldcard Mk4 to your computer.
• Navigate back to the "Settings" menu.
• Check the "USB Mode" setting to ensure it displays "USB Only".

If the setting is correct, you can be confident that your Coldcard Mk4 is now in USB-only mode. This verification step is crucial to ensure that your device is secure and operating as intended.

Benefits of USB-only Mode

Using USB-only mode on the Coldcard Mk4 offers several benefits. It enhances security by limiting the device's communication methods to a single, physically secure connection. This reduces the risk of remote attacks, such as those that could be carried out over Wi-Fi or Bluetooth. Additionally, USB-only mode can help prevent unauthorized firmware updates or other malicious activities that might be attempted through wireless connections. By using this mode, you can ensure that your cryptocurrency transactions remain as secure as possible.

Potential Drawbacks of USB-only Mode

While USB-only mode offers significant security benefits, there are some potential drawbacks to consider. For instance, this mode may limit the flexibility of your Coldcard Mk4, as you won't be able to use wireless features like Bluetooth or Wi-Fi for updates or other functions. Additionally, if you frequently need to move your device between different computers, you'll need to ensure that each computer has the necessary drivers and software to interact with the Coldcard Mk4 via USB. Understanding these limitations can help you decide if USB-only mode is the right choice for your specific needs.

Additional Security Measures

Enabling USB-only mode is just one part of securing your Coldcard Mk4. To further enhance the security of your hardware wallet, consider these additional measures:

• Use a strong and unique passphrase for your wallet.
• Keep your Coldcard Mk4 firmware up to date.
• Store your device in a secure location when not in use.
• Use the device in a private and secure environment to prevent shoulder surfing.

By combining USB-only mode with these additional security practices, you can maximize the protection of your cryptocurrency assets.

Troubleshooting Common Issues

If you encounter issues while enabling USB-only mode on your Coldcard Mk4, consider the following troubleshooting steps:

• Ensure that your USB cable is functioning correctly and properly connected.
• Restart the Coldcard Mk4 and try the steps again.
• Check for any firmware updates and apply them if available.
• If the issue persists, consult the Coldcard Mk4 user manual or contact customer support for further assistance.

These steps can help resolve common problems and ensure that your device operates smoothly in USB-only mode.

Best Practices for Using Coldcard Mk4 in USB-only Mode

To get the most out of your Coldcard Mk4 in USB-only mode, follow these best practices:

• Always use a trusted computer when connecting your Coldcard Mk4.
• Regularly back up your wallet data to prevent loss of funds.
• Use a hardware wallet-compatible software like Electrum or Sparrow Wallet for managing your transactions.
• Keep your Coldcard Mk4 and its USB cable in a secure location to prevent physical tampering.

By adhering to these best practices, you can ensure that your Coldcard Mk4 remains secure and efficient in USB-only mode.

Common Questions and Answers

Q: What is USB-only mode on the Coldcard Mk4?

A: USB-only mode is a security feature on the Coldcard Mk4 that restricts the device to communicate only via USB, thereby reducing the risk of wireless attacks.

Q: How do I enable USB-only mode on the Coldcard Mk4?

A: To enable USB-only mode, connect your Coldcard Mk4 to your computer, navigate to the "Settings" menu, select "USB Mode," choose "USB Only," and confirm your selection.

Q: Why should I use USB-only mode on my Coldcard Mk4?

A: Using USB-only mode enhances the security of your Coldcard Mk4 by limiting its communication methods to a single, physically secure connection, reducing the risk of remote attacks.

Q: Are there any drawbacks to using USB-only mode?

A: Yes, USB-only mode may limit the flexibility of your Coldcard Mk4, as you won't be able to use wireless features like Bluetooth or Wi-Fi for updates or other functions.

Q: How can I verify that USB-only mode is enabled on my Coldcard Mk4?

A: To verify, disconnect and reconnect the Coldcard Mk4, navigate to the "Settings" menu, and check that "USB Mode" displays "USB Only."

Q: What additional security measures should I take with my Coldcard Mk4?

A: Use a strong passphrase, keep firmware up to date, store the device securely, and use it in a private environment to enhance security.

Q: What should I do if I encounter issues while enabling USB-only mode?

A: Ensure your USB cable is functioning, restart the device, check for firmware updates, and consult the user manual or customer support if issues persist.

Q: What are some best practices for using the Coldcard Mk4 in USB-only mode?

A: Use a trusted computer, regularly back up your wallet data, use compatible software, and keep your device and USB cable secure.