Secure
Your Bitcoin

Dual Secure Element

COLDCARD provides the best Physical Security. Your seed words are stored in specialized chips, designed solely to securely store secrets.Now dual-vendor!

Verifiable Surce Code

All of the COLDCARD code is viewable, editable, verifiable and most importanly; reproducible. You can review, compile it yourself and prove it is what is claimed!

True Air-gap

COLDCARD is the only hardware wallet that avoids ever being connected to a computer, for its full life cycle: from seed generation, to transaction signing. Uses PSBT (BIP174) natively!

PRODUCT HIGHLIGHT

The COLDCARD Q

Bigger Screen

320x240 pixel LCD screen
3.2" diagonal size

QWERTY Keyboard

ideal for long BIP-39 passphrases

QR Code Scanner Done Right

LED illumination and advanced
scanning algorthme

Dual MicroSD Slots

Push-pull type, not spring loaded

Battery Powered

Airgapped and wireless 3x AAA
cells (or USB)

USB & NFC Data Block

Can be irreversibly blocked by
cutting PCB trace or NFC data

Bright Screen

3128x64 pixel OLED screen

Numeric Keypad

Entering pin is easy & quick

Sliding Cover

Protects screen and prevents
hardware implants

NFC-V Compatible

Tap to transmit all data types

Ultrasecure

Real crypto security chips

Explore the Line-up

Q vs MK4

  • Dual Secure Element

  • 3.2” LCD Screen

  • Full Keyboard

  • NFC

  • USB-C powered

  • AAA Battery powered

  • QR Code Scanner done right

  • Unlimited memory
    No Bitcoin transaction size
    restriction

  • Extensive duress PIN
    features

  • Dual Secure Element

  • Bright LCD Screen

  • Numeric Keypad

  • NFC

  • USB-C powered

  • Small

  • Simple

  • Unlimited memory
    No Bitcoin transaction size
    restriction

  • Extensive duress PIN
    features

Connectivity

Different ways to connect your
COLDCARD — OFF, by default

USB-C Connector

The industry-standard for transmitting both data and power over a single cable.

AirGap SneakerNET

Maximum security when transferring data between devices.

NFC Tap

Secure & very short-range wireless transmission that sends data to your phone easily

Virtual Disk

COLDCARD can emulate a USB disk drive, so sending PSBT files can be a drag-n-drop.

QR Scanner

COLDCARD Q feature QR Scanner done right with LED illumination, advanced scanning algorithms and serial interface.

Trick Pin

Trick PIN Features

COLDCARD has even more tricks up its sleeve!

Duress PIN

You may define an optional "duress PIN code". If anyone enters that PIN code, instead of the "real" PIN code, nothing special is shown on the screen and everything operates as normal... However, the bitcoin key generated is not the main key. It is effectively a completely separate wallet!

To take best advantage of this feature, you should put some Bitcoin into the duress wallet. How much you are willing to lose or what you need to make it plausible, we don't know.

The "duress" wallet will still be derived from the original BIP39 words, so you don't need to back it up separately, but there will be no way to get from that wallet back to the original wallet with the real funds in it.

Countdown to Brick PIN

This is a covert variation of the BRICK ME PIN mode. It forces a time delay (of minutes/hours/days) when logging into the Coldcard.

But once set, unlike the normal countdown, this special mode covertly bricks the Coldcard (or, optionally merely wipes the seed). Again, this may form some part of your game-theory for duress situations, but is completely optional.

The goal of this mode is to provide plausible deniability of a required time delay (similar to Bank's safes), while denying the attacker a functional device in case they take it away.

BIP39 Passphrases (25th word)

We support BIP39 passphrases so you can also create an unlimited supply of distraction wallets. This feature is also useful for your own organization of funds or accounts. Unlike the single duress PIN, an unlimited number of related wallets can be created using BIP39.

Brick Me PIN

Another PIN can also be defined, which we call the “Brick Me” PIN. Using that PIN code at any PIN prompt, will destroy the dual secure element and render your Coldcard worthless. Again, this may form some part of your game-theory for duress situations, but is completely optional.

Login Countdown

Force a time delay when logging into the Coldcard. Once enabled, you must enter the PIN correctly, and then wait out a forced delay (of minutes/hours/days) while a countdown is shown on-screen. Then enter your PIN correctly, a second time, to get in.

NEED MORE SECURITY?

Our other products

Seedplate

A better Bitcoin backup metal plate!

Single plate, 12 words per side (24 total)

Quality steel cut and etched in Canada

Etch marks chemically colored in black for better legibility

Designed to be small in size: only 5×3" (12.7×7.62 cm) for easier storage and concealment

Buy SEEDPLATE now

COLDPOWER

9volt Battery to USB adaptor

Level up on your USB P.P.E. and power your Coldcard or other low power USB devices from a standard 9-volt battery without any USB data concerns. Makes a great gift for the cypherpunk in your life. (5volts, 500mA max current)

Buy COLDPOWER now

BLOCKCLOCK mini

Our second bitcoin data display

Track prices from exchanges, see blocks as they are published by miners, and connect the Opendime to display balance, fiat value, and deposit QR codes on a timeless 7 E-Ink digital display.

Buy BLOCKCLOCK mini now

OPENDIME

World’s 1st and only real physical bitcoin

Opendime is a small USB that allows you to spend bitcoin like a dollar bill. Pass it along multiple times. Connect to any USB to check balance. Unseal anytime to spend online. Trust no one.

Buy OPENDIME now

See all products

PARTIALLY SIGNED BITCOIN TRANSACTIONS

Extreme Compatibility. PSBT ♥

Interoperation between Bitcoin hardware wallets is now possible, thanks to BIP174 which introduces a binary file format that all hardware wallets can use. COLDCARD has been based on BIP174 from day one, and uses it exclusively.

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Sleep Like a Baby
Technology™

Best-in-class security built in all of
our COLDCARD products.

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  • Q Mk4

    Dual Secure Element for Key Storage

    We find it quite scary that some hardware wallets trust the main microprocessor with their most valuable secrets. Instead, COLDCARD uses two Secure Elements, from different vendors, to protect your Bitcoin.

    Specifically, the COLDCARD uses Microchip's ATECC608 and Maxim's DS28C36B, to store the critical master secret: the 24-word seed phrase for your BIP39 wallet.

    For your funds to be compromised, a backdoor would need to exist for 3 different chips: both the Secure Elements, and the main microprocessor.

  • Q Mk4

    Genuine vs. Caution Lights

    To resist Evil Maids, and other sneaky people with physical access to your COLDCARD, we sign our firmware with a factory key. During boot-up, the firmware's signature, and nearly every byte of flash memory, will be verified and the appropriate Green/Red light set.

    Changing that light's status is actually controlled by dedicated circuitry connected directly to a Secure Element, so a rogue bit of software cannot override it. The circuit for the lights is exposed on the top surface of the product, so any physical tampering by those maids will be visible as well.

  • Q Mk4

    Anti-phishing Words

    The PIN code on COLDCARD is divided into two parts, such as 1234-5678. You first enter 1234 and then you will be shown two words on-screen. Those words are unique for all PIN prefixes, and for each COLDCARD ever made. (The secrets used to enforce that come from inside the secure element, and are unknown to the rest of the world.)

    Your job is to memorize those two words, keep them secret, and every time you use the COLDCARD, check them before entering the final 5678 part of your PIN. This protects you against a trojan-horse COLDCARD that might look like yours but it cannot know those two words.

  • Q Mk4

    Physical Security

    The carefully designed PCB increases the SE probing difficulty. Our clear case is part of our security model too, so you can look and see if a "hardware implant" has been inserted inside your device.

    Because of the in-depth use of the secure elements, there is no "factory reset" for the COLDCARD. If you forget your COLDCARD PIN, there is nothing we can do except remind you to recycle your e-waste responsibly!

    We've even put a label, "SHOOT THESE", for more effective device destruction... When the time comes.

  • Q Mk4

    Air Gap Operation

    COLDCARD never needs to touch a computer. It can work entirely from a USB power pack or AC power adapter. This includes everything you need to do in the whole life of the product:

    • Initial PIN choosing and setup.
    • Pick your 24-seed words using our TRNG, import existing secrets, or use your dice rolls.
    • Export skeleton wallet files, for setup of Electrum or other desktop/mobile wallets.
    • Export lists of payment (deposit) address, using the Address Explorer.
    • Backup of seed and settings, which saves an encrypted 7z file.
    • Sign transactions for spending your Bitcoin, using PSBT files (BIP174) from any standards-compliant wallet
    • Firmware upgrades
    • Advanced users can even setup a multisig wallet between multiple cosigners, entirely on-device, and air gapped

    Using our industrial grade MicroSD Cards or any standard MicroSD card, for each of the above steps that require data to come in and out. Sneakernet for the win! If you want to reach the next level paranoia, you can use different cards for the data coming into versus out of the COLDCARD, and/or use cards a single time only.

  • Q Mk4

    Dice Roll and Provable Bitcoin Seed Generation

    If you don't trust our random number generator, you can generate the BIP39 seed phrase using dice rolls. We help with this process: you just have to press 1–6 for each roll (99 rolls recommended). At the end of that process, you'll have a properly-encoded seed phrase based solely on the dice rolls. Learn how to verify COLDCARD's dice-rolls math here.

SUPPLY CHAIN PROTECTTION

Getting an uncompromised
product into your hands

Unique Bag Number

We use a unique tamper-evident plastic bag to package your new COLDCARD. Each bag is unique and coded with a serial number. That "bag number" is written into the COLDCARD's as it's put into its bag. That value cannot be changed, and we ask your to verify the bag number when you power-up the COLDCARD for the first time.

Clear Case

The clear plastic case on COLDCARD is an important feature as well. There have been demonstrations of inserting custom hardware inside a competitor's hardware wallet to capture key-presses.

LEARN EVEN MORE

Video Walkthroughs

How to Clone/Migrate from Mk4 to COLDCARD Q

Mar 12, 2024

Tutorial: NFC Push Tx

Jun 26, 2024

Tutorial: Multisig (Desktop)

Jul 18, 2024

Tutorial: Applying a Passphrase

Jul 10, 2024

Coldcard Q Bitcoin Wallet - Beginner Tutorial

Feb 21, 2024

Coldcard Q Bitcoin Wallet - NFC On Mobile Tutorial

Feb 24, 2024

Creating a bitcoin multisig wallet with Nunchuk, TAPSIGNER and COLDCARD

Jun 30, 2023

Coldcard Q - Secure Offline Password Manager

Jul 11, 2024

Coldcard Q Bitcoin Wallet - Air Gapped QR Device for Mobile and Desktop

Apr 15, 2024

Spanish guide: COLDCARD Mk4 Tutorial

Jun 29, 2023

Italian guide: Bitcoin Core + COLDCARD

May 30, 2023