Ballet Crypto: Cold StorageApp Store
Our wallet review process
We examine wallets starting at the code level and continue all the way up to the finished app that lives on your device. Provided below is an outline of each of these steps along with security tips for you and general test results.
Application build test result
Ballet Crypto is an app that acts as a companion to your Ballet product, allowing you to manage your cryptocurrencies, check their market value and add additional ones to your wallet.
The app does not store your wallet’s private keys. It also does not track, store or transmit your personal or financial data outside the app.
This app is the companion app to BIP38 encrypted private key “paper” wallets. The idea is that the company Ballet Global Inc. sells credit card sized tokens that carry an address, a private key and a password while the app itself doesn’t store the private keys.
We usually classify companion apps that do not store private keys as “not a wallet” but here the security aspects of the “hardware wallet” as they call it are so blatantly different that we have to consider the app a wallet anyway.
Yes, the provider claims that the private keys doesn’t get stored in the app but in contrast to actual hardware wallets that never expose the private keys to companion apps, this BIP38 wallet’s private keys get reconstructed in the app, supposedly to do a send but we are all about verification, so we would like to know if we could audit the app to see if it really doesn’t secretly send the private keys to some server.
The other obvious issue is that the private keys are all generated by the provider! The cards they sell are what protects the keys. There is no way of knowing if anybody in the supply chain is keeping copies. The founder of the company Bobby Lee, a well known figure in the Bitcoin space acknowledges that trust is needed but emphasizes that he is trustworthy. In the spirit of “Don’t trust - verify!” we would/will certainly file this “hardware wallet” also as not verifiable but the companion app given the lack of source code is also not verifiable.
Do your own research
In addition to reading our analysis, it is important to do your own checks. Before transferring any bitcoin to your wallet, look up reviews for the wallet you want to use. They should be easy to find. If they aren't, that itself is a reason to be extra careful.