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Ballet Crypto Pure

🔍 Last analysed 23rd March 2022 . Leaks Keys
19th September 2021

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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 have these attributes:

  • secure initial setup
  • tamper evidence
  • balance check without revealing private keys
  • small size
  • low unit price
  • either of ...
    • somebody has a backup and needs to be trusted
    • nobody has a backup and funds are destroyed if the token is lost/damaged

The Analysis 

Similar to the Casascius coins but built to be the same size as a credit card, Ballet Crypto Pure is the next iteration of Ballet’s physical bitcoin product series. It comes in denominations of 0.1, 0.025, 0.01 or 0.005 BTC. It comes in stainless steel, 24K gold-plated or plastic. Both the public address and the private keys are physically located on the card. The manufacturer assures that they do not keep records of the private keys through their Two-Factor Key Generation (2FKG) production process:

Two critical private key components are generated in a geographically segregated, multinational private key production process.

To keep up with BIP38 standards and to verify authenticity of the cards, Ballet put up balletcrypto.org which should be accessed subsequently with an offline and secure device. The process is as follows:

Step 1

Enter your wallet passphrase. Remove the tamper-evident scratch-off to get the wallet passphrase.

Step 2

Verify using BIP38 confirmation code. You can use the Ballet Crypto mobile app to get your wallet’s BIP38 confirmation code.

OR

Decrypt using BIP38 encrypted private key. Peel off the top layer sticker and scan the encrypted private key QR code, which is set against a yellow sticker.

Interface

The question despite all the processes involved in ensuring that the private keys are not recorded by the manufacturer, is trust. Do we trust the manufacturer to be faithful in ensuring that their 2FKG process is upheld? Ballet Crypto is founded and headed by CEO Bobby Lee, a long time cryptocurrency personality also known to be involved in BTC China and bitcoin mining. An extreme and overabundance of caution, would say, “Don’t Trust - Verify”.

It’s also important to note that Ballet Crypto could also require a companion app: Ballet Crypto No Source!

The Ballet Crypto app is a companion app to your Ballet wallet. When using the app, your assets are kept completely offline on your wallet. The app does not store the credentials of your wallet and cannot access your private key. Your assets are kept offline and no one can hack or otherwise gain access to your funds through the app.

In conclusion, although the Ballet Crypto Pure may indeed prove to be a “nice” novelty item for holding bitcoin, its lack of an interface, dependence on a companion app, the physical inclusion of both the private key and the public address on the device means that if someone can take possession of the card it can be compromised. Like most bearer assets, the Ballet Crypto Pure can be passed on from one user to another as a collectible.

(dg)

Verdict Explained

This product requires sharing private key material!

As part of our Methodology, we ask:

Does the device hide your keys from other devices? If not, we tag it Leaks Keys!

Some people claim their paper wallet is a hardware wallet. Others use RFID chips with the private keys on them. A very crucial drawback of those systems is that in order to send a transaction, the private key has to be brought onto a different system that doesn’t necessarily share all the desired aspects of a hardware wallet.

Paper wallets need to be printed, exposing the keys to the PC and the printer even before sending funds to it.

Simple RFID based devices can’t sign transactions - they share the keys with whoever asked to use them for whatever they please.

There are even products that are perfectly capable of working in an air-gapped fashion but they still expose the keys to connected devices.

This verdict is reserved for key leakage under normal operation and does not apply to devices where a hack is known to be possible with special hardware.

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.