The Coldcard MK4, developed by Coinkite, is a fully air-gapped Bitcoin-only hardware wallet. The Coldcard is highly sought after amongst hardcore Bitcoin enthusiasts, with it's simplistic design and vast array of security features on top of what you'd expect from a market-leading hardware wallet.
The Coldcard MK4 uses fully open source technology. Anyone is able to view, edit and verify the code. The verifiability of the device allows the brightest minds in the Crypto space to evaluate and test the workings of the device, making for exceptionally high security standards.
Creating a backup of your seed phrase is quick an easy using a Micro SD card. You can also display your seed words if you wish to create a more durable, long-term backup.
- Full-sized numeric keypad
- Bright OLED screen
- Shipped in a tamper-evident bag, with verifiable bag number
- Reduced Attack Surface (BTC-only support)
- Dual secure element for storing seed words
- Engineered and manufactured in Canada
- USB-C compatibility (Highly durable USB-C cable included)
- Fully open source and verifiable source code
Different ways to connect
There are numerous ways to connect using the Coldcard MK4, all allow for a secure connection to be made without exposing your private keys.
- USB-C Connector - The industry standard for transmitting both data and power over a single cable (USB-C cable included).
- AirGap SneakerNET - Maximum security when transferring data between devices.
- NFC Tap - Secure and very short-range wireless transmission that sends data to your phone easily.
- Virtual Disk - The MK4 can emulate a USB disk drive, so sending PSBT files can be a drag-n-drop.
Trick PIN features
Where the Coldcard MK4 differs from other hardware wallets on the market, is with it's range of optional features which can be used to enhance the security of your device, including:
- 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!
- BIP39 Passphrases (25th word) - Coldcard supports BIP39 passphrases so you can also create an unlimited supply of distraction wallets. This feature is also useful for your own organisation 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.
- 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).
- 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.
Is Crypto Nest an authorised reseller?
Yes. We have official agreements in place with all of the brands we offer. You can verify this by contacting the brands directly or by viewing their official reseller lists.
All items are shipped directly from the manufacturers to our secure warehouse facility here in the UK and then straight to our customers around the world.
What are my delivery options?
If you're a UK customer you can take advantage of our free next-day delivery service via Royal Mail Tracked 24 delivery. This option will automatically apply once you've inputted a UK address at checkout, no minimum spend required.
For our international customers, we offer an International Signed/Tracked service and aim to deliver all items within 3-10 days (depending on the delivery location).
All orders placed before 3pm Monday-Friday and before 11am Saturday will be dispatched same-day.
See our full Shipping Policy here.
What is your Returns Policy?
We offer a full 30 day returns policy. If you are not 100% satisfied with your order within 30 days of receiving delivery of the items then you can request a refund for your order.
See our full Returns Policy here.