Posted in: Archive
May 30, 2014 12:30 AM UTC

Cryo Card Review: Nearly Indestructible Bitcoin Cold Storage

Cold storage is perhaps the safest way to store your bitcoins (or any other cryptocurrencies) since cold wallets are kept offline. Anyone can send money to a cold wallet, but retrieving funds from cold storage isn't possible without physical access to the wallet, making this…

Cold storage is perhaps the safest way to store your bitcoins (or any other cryptocurrencies) since cold wallets are kept offline. Anyone can send money to a cold wallet, but retrieving funds from cold storage isn’t possible without physical access to the wallet, making this storage option a lot safer from online hackers. Many people print their private keys on paper, creating a “paper wallet”. However, these types of wallets are susceptible to flooding, fires, ink wearing away, and more. Fortunately, CryoBit has created a more elegant solution – the Cryo Card.

CryoBit claims to have created “the ultimate solution to offline cold storage” that is flood-proof, fireproof, and more. I wanted to see if CryoBit’s claims were true, and the company was nice enough to send a free Cryo Card for me to review. Keep reading to see my impression of Cryo Card.



[dropcap size=small]Y[/dropcap]es, this needs to be in all caps. Cryo Card displays your bitcoin address on the front and your BIP38-encrypted private key on the back. On the Products page, you’re given the option to enter your existing wallet information or generate a new wallet address. The second option is what bothers me.

When you click the “Create New” button, the following screen pops up:

Here, you’re expected to enter your secret passphrase that decrypts your wallet, and hope that CryoBit isn’t storing this passphrase. There is no reason to trust CryoBit, or anyone for that matter, when it comes to securing your bitcoins. Even if the company isn’t storing passphrases, you should never generate a cold wallet on an online computer; that just defeats the purpose of a cold wallet. You could have a keylogger on your computer that would capture and send that passphrase to a remote server. The safest way to create a cold wallet is to:

  1. Download the source code for onto a blank flash drive.
  2. Open on a system that was never connected to the Internet (you could boot into a live linux distro and open on that).
  3. Go to the “Paper Wallet” section and choose “BIP38 Encrypt”.
  4. Enter your passphrase and hit the “Generate” button to get your wallet address and encrypted private key.
  5. Now enter your wallet address and encrypted private key on CryoBit’s website.

Does this seem a little paranoid? It’s not. Cold storage is intended to house nearly all of your bitcoins, so no security measure is too excessive.

After entering my wallet information, I was taken through standard checkout screens with shipping information, payment, etc., and about a week later, the Cryo Card arrived.


What makes Cryo Card so cool is its simplicity. It’s basically just a sheet of tough stainless steel with your wallet information etched on it.

My wallet address
My encrypted private key

The package I received also came with a sleek carrying pouch, an information sheet, and a nice card.

A small paper pouch for the card
Information about CryoBit
A nice card from Brian Atchley – cofounder of CryoBit

CryoBit likes to repeatedly point out Cryo Card’s overall strength.

“Engineered to withstand anything mother nature can throw at it; Cryo Card’s base layer is constructed of AMS 5524 Stainless Steel, an aerospace grade metal that demonstrates both high heat and corrosion resistance in all environments. It is highly resistant to both acids and bases, fresh and salt water, and temperatures of up to 2500°F (1370°C). Cryo Card is then marked by a high-contrast proprietary ceramic-glass material that exceeds the metal’s oxidative and thermal performance. In addition, this marking material is virtually scratchproof. Since the marking is chemically bonded to the base metal and is comprised of a very hard ceramic composite, it is nearly impossible to remove by any form of physical or chemical abrasion – without first removing the metal layer underneath.”

Sounds great, but I wanted to see for myself whether or not these claims were true.

Drop Test

The first thing I tried was dropping the card from a height. You can see my three trials in the video below:

And here are the results:

You can see some scratching and scuffing on the bottom right corner, but there wasn’t much more than that. Furthermore, both QR codes remained scannable.

Acid Test

The next thing I tried was exposing Cryo Card to acid, specifically vinegar with a pH of 5. You can watch the video below, but spoiler: nothing happens.

Flame Test

The last thing I tried was exposing Cryo Card to fire. CryoBit states that Cryo Card can withstand temperatures up to 1370°C, but the results weren’t exactly what I expected:

There’s some obvious discolouration at the bottom and the card as a whole got a lot darker.

This is how the card used to look before being dropped several times and being exposed to fire.

To be fair, the QR codes are still scannable. In fact, there’s a video online of CryoBit torching the Cryo Card:

As you can see, the QR code becomes harder to see, but it still scans successfully. All in all, it seems like Cryo Card can handle pretty much anything.

Overall Impression

A double-sided Cryo Card costs $30, which might seem like a lot, but I think it’s a fair price considering how tough Cryo Card is. If you’re planning on storing almost all your bitcoins on this one card, then $30 is a solid investment for what is an almost indestructible cold storage solution. The only thing I’d like to stress is that if you choose to buy a Cryo Card, generate your own wallet using the steps above. Do not create a wallet address+private key pair on an online computer.

Last modified: January 25, 2020 10:03 PM UTC

Neil Sardesai @@neilsardesai

I enjoy keeping up with the latest stuff in science and technology and have been following Bitcoin for a few years now. I also occasionally post cool stuff on twitter.

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