Major UX upgrade for the flagship Bitcoin hardware wallet

Coinkite, a Bitcoin-specific hardware wallet manufacturer, recently launched MK5. MK5 builds on the strong security foundation established by previous versions and significantly upgrades the quality of life and user experience with MK4 Coldcard. The MK5 is available in a variety of colors and styles. Today we’ll review the Orange and Glow in the dark versions and their form factor and user experience upgrades to answer the following questions: Is upgrading your device worth the money?

It is built on the well-known and trendsetting MK4 security platform, which integrates two secure element chips and MCUs from different manufacturers in the same device. Instead, the MK5 focuses on quality of life and brings new features such as improved NFC connectivity, reworked the hardware wallet’s buttons and plastic chassis, and added a much larger screen. This is the first hardware upgrade to the Coinkite MK line since the launch of the MK4 in 2022, incorporating some of the technology that debuted in the Coldcard Q in 2023.

What’s new in MK5 Coldcard?

The massive upgrade to the UX is immediately noticeable. For starters, the screen is much larger, perhaps 30% larger. Their announcement blog describes it as having a “1.54-inch display protected by Gorilla Glass,” which makes it look and feel much more rugged than previous models.

The next obvious upgrade is the buttons. Unlike the recessed MK4 buttons that require your finger to enter the socket to click, the MK5 buttons are much easier to press as they are almost flush with the device’s chassis. It feels good when pressed, has a clicking sound, and provides positive tactile feedback to the user. It’s a lot more comfortable than the warm, slightly uncomfortable, unresponsive touchscreen feel of other hardware wallets.

You’ll also quickly notice that the chassis has been redesigned. Sections of the screen no longer stick out above the keyboard. Instead, it’s all one rectangle with comfortably curved edges. It looks more modern and elegant while maintaining the signature design principle of Coinkite products: cypherpunk transparency showcasing the underlying hardware.

The MK5 also comes with buttons with slide and click functions and a screen protector half case. It can be completely removed and fits perfectly into the back of the device, exposing the USB power input on the bottom of the device without issue.

NFC push transaction

Finally, Coinkite has doubled down on NFC support with the MK5. NFC antenna, short for Near Field Communication, is a technology stack that is becoming increasingly popular in the Bitcoin industry. From NFC taps to Lightning Bolt card payments with a cool design and laser eye, Coinkite’s own Tapsigners, and Cashu’s tap sending functionality developed by Calle.

NFC is a powerful alternative to other wireless connectivity technologies such as Bluetooth or Wi-Fi that some hardware wallet providers have adopted, but it has some controversial drawbacks, mainly range. Unlike alternatives, NFC is short-range by design. We speak of ranges in centimeters, whereas Bluetooth and Wi-Fi speak of tens of meters. This eliminates the paranoia-level threat that someone targeting your home with a long-range antenna could capture your transactions on the move or remotely connect to your devices.

NFC also lacks a multi-step device connection protocol. If the feature is turned on or off on your phone, the app may start scanning and a transfer may occur. There are no pin codes or having to look through the list of Bluetooth-enabled devices. In theory, it’s a much simpler UX. It’s also a much better user experience than transferring pre-signed transactions to an SD card from your laptop or phone. While NFC may technically cross the ‘air gap’ line on the MK4 and MK5, NFC still offers the best quality of all wireless connectivity options and is set to off by default. Similar to the option of connecting the MK5 to a computer via USB for data transfer, the NFC antenna can also be cut at the hardware level by scraping certain wires within the hardware.

Coinkite’s NFC Push Tx software is open source and requires much smaller lines of code than Bluetooth or Wi-Fi. The entire NFC Push Tx code is open source. There is no license defined on the client web app side of the protocol and will probably be integrated by all web applications. The hardware aspects of the code are open, but restricted by a non-commercial use license.

Colors of MK5

To satisfy Bitcoiner’s thirst for collectibles, the MK5 is available in a variety of cases, including gold-plated transparent gray, brilliant orange, and even glow-in-the-dark! I had to play with the orange and blue glow-in-the-dark versions, but I wish I had gotten my hands on the gold foil pieces.

Nonetheless, the design is beautiful, transparent enough to show the hardware, yet colorful enough to be stylish. Here’s what it actually looks like:

supply chain security

The packaging was also very interesting. The box containing the hardware came with a purchase order for the item, and the item was placed inside a tamper-evident security bag. This bag was made of pretty strong plastic so I had to cut it with a knife as I couldn’t tear it easily. The bag is also marked with a unique number as shown in the photo below. Inside the bag was another plastic strip with the same number written on it. And when I first powered on the device, the screen showed the same numbers. This is a flash memory code set for each device at the factory. It becomes much more difficult to intercept and manipulate hardware firmware. The next step is to notify the user of their bag number via email or through site login. This also allows users to have a side channel to verify numbers.

If there is an issue with the packaging, please take a photo and contact Coinkite Support.

The battery and exposed hardware device in the photo below is Coinkite’s COLDPOWER adapter, and I happened to be lying down and thought I’d test it too. Even rogue Wi-Fi that is repeatedly plugged into a power outlet can transmit signals through wires, so this is to ensure that there are no cables connected to the computer at all and that the device is fully powered (lol).

What needs to be improved?

Integration of NFC Push Tx with mobile wallets was a bit inconsistent. I tried Cove, Bull Bitcoin and Nunchuck. Of the three, Nunchuck is the best integrated, with Cove not far behind. Bull Bitcoin seems to have disabled that feature or hid it pretty well. Cove is a young project that is likely to make leaps and bounds in the coming months, while Nunchuck, a very advanced and powerful wallet, took a few minutes to figure out, but ultimately turned out to be the best interface of the three.

Even with a more powerful NFC antenna, I still had to remove the phone’s ridiculously thick case to get reliable data transfers, but that’s not the end of the world.

Conclusion: Is the MK5 worth the upgrade?

What I do know now is that, as the proud owner of an ancient MK3, the move to the MK5 is a significant upgrade, and for the low cost of $167 plus shipping, I’d say it’s a no-brainer. That’s a whole generation of security and UX upgrades I didn’t realize I needed.

For active users of the MK4, the larger screen and better buttons will certainly improve quality of life, while a better NFC antenna will also pay dividends by making transactions flow more smoothly. Again, compared to other hardware wallets on the market, the price is very reasonable.

But for passive MK4 owners who trade in a couple of times a year, it might not be worth squeezing that juice. They will still receive firmware updates, enjoy all the security benefits, and won’t miss out on the improved UX as much.

Disclaimer: Coinkite provided Bitcoin Magazine with two free MK5 cold cards to use for the purpose of testing the product for review.