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Black Metal Crypto Cards

🔍 Last analysed 23rd March 2022 . Provided private keys

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Do your own research!

Try out searching for "lost bitcoins", "stole my money" or "scammers" together with the wallet's name, even if you think the wallet is generally trustworthy. For all the bigger wallets you will find accusations. Make sure you understand why they were made and if you are comfortable with the provider's reaction.

If you find something we should include, you can create an issue or edit this analysis yourself and create a merge request for your changes.

What is a bearer token?

Bearer tokens are meant to be passed on from one user to another similar to cash or a banking check. Unlike hardware wallets, this comes with an enormous "supply chain" risk if the token gets handed from user to user anonymously - all bearer past and present have plausible deniability if the funds move. We used to categorize bearer tokens as hardware wallets, but decided that they deserved an altogether different category. Generally, bearer tokens require these attributes:

  • Secure initial setup
  • Tamper evidence
  • Balance check without revealing private keys
  • Small size
  • Low unit price
and either of these applies:
  • Somebody has a backup and needs to be trusted.
  • Nobody has a backup and funds are destroyed if the token is lost or damaged.

The Analysis 

Product Description

The cards are made of grade 304 stainless steel and are 0.5 mm thick. It supports any cryptocurrency. The public keys and the private keys are optionally printed for free. You can order the QR code together with a passphrase. The provider will print the QR code. Scratch-off stickers to cover the QR codes are also provided for free.

Analysis

The provider printing the QR codes for the user means that they will have access to copies of the private key. Their security measures are detailed on this page.

Further proof that the card is more of a novelty item that you shouldn’t accept as payment:

How long is my wallet data and/or QR codes saved on your website? The public address, private key and all related order details are automatically deleted after 2 months. This gives us enough time to process your order. And you enough time to review it or ask us questions about it.

After 2 months, we wouldn’t need to keep your data. And to prevent your wallet info being leaked during a data breach, this seemed like the safest option for us.

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Verdict Explained

The device gets delivered with private keys as defined by the provider!

As part of our Methodology, we ask:

Provided Keys!

Are the keys never shared with the provider?

If the answer is "no", we mark it as "Provided private keys".

The best hardware wallet cannot guarantee that the provider deleted the keys if the private keys were put onto the device by them in the first place.

There is no way of knowing if the provider took a copy in the process. If they did, all funds controlled by those devices are potentially also under the control of the provider and could be moved out of the client’s control at any time at the provider’s discretion.

The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.