COLDCARD Mk4 review

The COLDCARD Mk4 hardware wallet was designed to help you to safely store the private keys to your Bitcoin (BTC) — and your BTC only.

The first COLDCARD wallet came to market on Sept. 11, 2018, and the Mk4 is the latest iteration of the wallet.

The information on the device is protected by not one but two Secure Element chips — the same chips found in passports and credit cards — and you can use the device without connecting it to the internet.

But said security comes at a price.

The wallet itself runs for $157.94, and once you buy all of the accessories you need to get started using the wallet, your bill could top $200.

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What’s in the bag?

⚠️ Must read

Anytime you buy a hardware wallet you must ensure the product hasn’t been tampered with, otherwise your private keys may be compromised. Check that what you received matches what is listed on the retailer’s website, and carefully check that no tamper-proof seals or packaging have been damaged.

COLDCARD Mk4 price

The COLDCARD Mk4 costs $157.94. But you must purchase more than the device to use it.

You will also need to purchase a Power-Only USB-C Cable (US$16.99), a COLDPOWER Adapter (US$24.99) and a 9V battery if you want to refrain from plugging your device into your computer for charging power.

If you don’t mind plugging the device into your computer, you only need to buy the Power-Only USB-C Cable.

You will also need to buy a microSD card. Industrial-grade versions of these are sold on COLDCARD’s website for US$39.94.

When you add up all of the hardware necessary to get started with your COLDCARD Mk4, you could spend upwards of $229.

This price point is far higher than that of a Ledger Nano S Plus ($79) — which also uses a Secure Element chip to safely store the private keys to your Bitcoin (BTC) offline.

Another reputable and cheaper hardware wallet for storing your Bitcoin is the Trezor Model One — which costs $59. This hardware wallet doesn’t use a Secure Element chip, though.

Where to buy the COLDCARD Mk4

Purchase the COLDCARD Mk4 through the official Coinkite website. Coinkite is the parent company of COLDCARD.

If you purchase it through a third-party provider, you may be purchasing a device that’s been tampered with and is therefore compromised.

COLDCARD Mk4 coin support

The COLDCARD Mk4 only permits you to store the private keys to your Bitcoin (BTC). It does not allow for the storage of private keys to altcoins or NFTs.

COLDCARD Mk4 security

The COLDCARD Mk4 uses two Secure Element chips — from two different manufacturers — to minimize security risk. Ledger hardware wallets only have one Secure Element chip, and Trezor wallets have zero.

AirGap support

The COLDCARD Mk4 allows you to make transactions without connecting the wallet to the internet.

To make such transactions, you download data from your COLDCARD Mk4 to a microSD card then insert the card into your desktop computer.

Once inserted, you can make transactions using that data via an assortment of software wallets including Sparrow Wallet — the most widely recommended desktop wallet to use with your COLDCARD Mk4.

Multiple PINs

Create multiple pins for your COLDCARD Mk4. The PINs can help to more securely store your BTC.

Two types of PINs you can create are a Duress PIN and a Brick Me PIN.

• Duress PIN. If you find yourself under duress — that is, being attacked for your BTC — you can give your attacker this PIN. It will open a wallet in which you can store an amount of BTC you’re willing to lose and not the full amount of BTC that you manage on your Mk4.
• Brick Me PIN. By entering this PIN, you command your COLDCARD Mk4 to self-destruct. Once you enter this PIN, the device becomes useless. Use this PIN also as a security measure when you discard an old, unused device.

COLDCARD Mk4 vs. Mk3

	Mk4	Mk3
Connector	UCB-C	Micro USB
Number of Secure Element chips	2	1
CPU apeed	120 MHZ	80 MHz
Memory	840 kB + 8 MB RAM	360 kB
Flash memory (firmware)	1.5 MB	700 kB
Settings memory	512 kB	4 kB
USB-in-use LED light	Yes	No
Sliding cover	Yes	No
Firmware upgrade time	15 seconds	2 minutes
Bitcoin transaction size limit	2 MB	384 kB

How to set up the COLDCARD Mk4

If you plan to set up your Mk4 without connecting it to your desktop, you’ll need all of the items that come in the bag with the wallet. These include a USB cable, a COLDPOWER adapter, a 9V battery, a microSD card and a microSD card adapter if your desktop computer doesn’t have an input for one.

If you plan to connect your Mk4 directly to your computer, you’ll only need the device and a Power-Only USB-C cable.

You’ll also need to download a desktop wallet like Sparrow Wallet, Electrum or Wasabi to your computer.

After doing all of this, follow the instructions on your device once you power it up for the first time.

There are numerous tutorials online to assist in this process.

How to use the COLDCARD Mk4

Using your COLDCARD Mk4 can be a little more complicated than using Ledger or Trezor devices and their corresponding software.

Visit COLDCARD’s site for detailed instructions for how to send and receive BTC with your Mk4.

COLDCARD Mk4 vs. other hardware wallets

While the COLDCARD Mk4 has some features in common with Trezor and Ledger wallets, it’s unique in multiple ways, as well.

One major difference between the COLDCARD Mk4 and Ledger and Trezor wallets is that the COLDCARD Mk4 doesn’t have native desktop software, while Ledger and Trezor wallets do.

• COLDCARD vs. Trezor

  The COLDCARD Mk4 only allows you to store the private keys to your Bitcoin (BTC). The Trezor Model T — Trezor’s flagship hardware wallet — allows you to store the private keys to 1,000+ digital assets as well as NFTs on the Ethereum blockchain.

  The Trezor Model T also has a touch screen, whereas the COLDCARD Mk4 doesn’t.

  The COLDCARD Mk4 uses two Secure Element chips as a security measure, whereas Trezor wallets don’t feature an equivalent type of secure internal hardware.

  COLDCARD and Trezor wallets have been developed with open-source code, which means that anyone can audit the code for security bugs.

• COLDCARD vs. Ledger

  The COLDCARD Mk4 only allows you to store the private keys to your Bitcoin (BTC), while Ledger wallets allow you to store the private keys to 5,500+ digital assets as well as NFTs on many different blockchains.

  COLDCARD and Ledger wallets all contain Secure Element chips. The COLDCARD Mk4 contains two of them for extra security.

  COLDCARD wallets have been developed with open-source code, which means that anyone can audit the code for security bugs. Ledger wallets have been developed with closed-source code.

COLDCARD Mk4 alternatives