NFT Materialization with an NFT Cryptnox Card

Cryptnox Cards
4 min readOct 2, 2022


Crytpnox is developing and producing hardware wallets (cold storage) in smart card format
In this article, we will explain how to use a specific version (B-NFT-1)of the card for perfect NFT materialization. This card type was specifically designed for this purpose, and at the end of this article, we will explain in a technical section why this is only achievable with this card. As of the date of publishing this article, the NFT Cryptnox Card is not officially on the market.

In this article, we will show how to materialize this NFT on a Cryptnox NFT card:

It was minted on the NFT marketplace Opensea using the store smart contract on Polygon chain (ERC1155).

The corresponding page looks like this (you can look at it here) :

Part 1:

Copy the URL of the display page of the NFT as above. In our case it will be:

Part 2:

Download and install Cryptnox NFT Manager here (Only on Microsoft Windows for now).

Start it, and paste the above copied URL in the URL field, and press the Get fields button.

The app display will look like:

Part 3:

Put a Cryptnox NFT Card in a card reader (only one reader and one card), and press the Execute load button. Wait for 2–3 seconds as the car generates an internal random key pair, and then you will get the following display:

Look at the following field:

Your card address:

This is the public key of the on-card generated key pair !

Part 4:

Now we go back to the above NFT Opensea marketplace page, and we will transfer the NFT to the address of the card. Press the Transfer button on the upper right, and put the card address as recipient:

Validate with your Web3 wallet (It can perfectly be a Cryptnox Hardware Wallet Card, using Walletconnect). Then the transfer should be completed:

And now that the NFT is transferred to the address of the card, it is materialized on a Cryptnox NFT Card !

Chek on the NFT Manager app and press the Card info button. This appears:

As you can see, the Checking owner contract field = OK (it was not the case when the card was loaded, before performing the transfer).

Let’s get a bit more technical for a sec, so that you can grasp the technical materialization aspect. Look at the following data:

“No history entries”

This means that the private key was never used, thus no digital signature was ever performed with the private key generated on the card. Who ever is holding the card is 100% sure to be the sole owner of the card ! This cannot be completed with any other kind of hardware wallet as of this date !

Want to perform the above check on your phone ? Want to stream the NFT to your Apple TV ? Download the Cryptnox Wallet app from the Apple Store:

Start the App, scan the Crpytnox NFT Card and the corresponding menu will appear. Enjoy !!



Cryptnox Cards

Cryptnox is a swiss based company developing smart cards (hardware wallet) for blockchain