Coinkite Releases Major COLDCARD Firmware Update with BIP-322 Signing, WIF Key Support, and Enhanced Security Features

Coinkite's COLDCARD firmware update adds BIP-322 signing, WIF key import, and a transaction input explorer for enhanced security and control.

TORONTO, ONTARIO, CANADA, March 6, 2026 /EINPresswire.com/ -- Coinkite, a leading developer of premium Bitcoin hardware wallets, today announced a significant firmware update for its COLDCARD product family, including both the Mk and Q models. The new release introduces powerful new capabilities for users, including BIP-322 "Proof of Reserve" signing, WIF (Wallet Import Format) key storage, and a host of other enhancements designed to improve functionality and security.

The update empowers users with greater control over their bitcoin holdings and provides new tools for advanced wallet management and verification.
Key new features in this release include:
BIP-322 Signing

COLDCARD now supports signing BIP-322 "Proof of Reserve" PSBT files. This feature allows users to securely and comprehensively prove control over a list of UTXOs while committing to a short text message. This long-awaited Bitcoin Improvement Proposal, assigned in 2018, is now a practical tool for demonstrating ownership of funds in a verifiable way. Users will need a compatible wallet or tool to generate the specialized PSBT required for this process.

WIF Store
The new WIF Store functionality allows users to import foreign private keys in Wallet Import Format (WIF) and use them for PSBT signing. Keys can be imported via SD card, Virtual Disk, NFC, QR code scanning, or manual entry. Once stored in the WIF Store, the COLDCARD will automatically sign any PSBT requiring that key. This feature is particularly useful for recovering funds from paper wallets, cashing out an OPENDIME, or in specialized emergency situations, and can operate independently of the device's master seed. Up to 30 keys can be stored securely.

Export BIP-380 Extended Key Expression
Users can now export BIP-380 extended key expressions, which are essential for setting up multisig or single-signer wallets. These expressions, in the format [XFP/p/a/t/h]xpub, provide all the necessary information for wallet configuration. The feature supports common address derivations and allows for custom path specification.
Transaction Input Explorer

A new Transaction Input Explorer has been added, allowing users to inspect detailed data about the UTXOs being spent in a proposed transaction. By pressing the (2) key before approving a transaction, users can page through the inputs, providing a crucial verification step similar to the existing output explorer for destination details.

Additional Features and Enhancements
- The update also includes numerous other improvements:
- Support for v3 transactions in PSBT files.
- An option to type a derived BIP-85 secret as an emulated USB keyboard.
- A "Nuke Device" option to purge all sensitive data, rendering the COLDCARD as e-waste.
- A CCC debug menu to reset block height.
- The ability to display the BIP-39 passphrase on-screen after activation.
- A new "Buried Settings" menu for rarely used configurations.
- The addition of "Blue Wallet" to the "Export Wallet" options.
- Detection of duplicated inputs in PSBT files.
- A bug fix for exported file names in multisig wallet exports.

Model-specific updates include:
Mk (v5.5.0): An enhancement to show QR codes of XOR-split seeds.
Q (v1.4.0Q): A bug fix for an issue with empty notes in hobbled mode.

The new firmware is available now for all COLDCARD Mk and Q devices. Users are encouraged to update their devices to take advantage of these new features.

About Coinkite:
Coinkite is a developer of bitcoin security products, including the COLDCARD hardware wallet series. The company focuses on security, privacy, and open-standard principles, creating tools for users managing their own bitcoin assets.

Austin Green
Coinkite Inc.
ag@coinkite.com

Legal Disclaimer:

EIN Presswire provides this news content "as is" without warranty of any kind. We do not accept any responsibility or liability for the accuracy, content, images, videos, licenses, completeness, legality, or reliability of the information contained in this article. If you have any complaints or copyright issues related to this article, kindly contact the author above.