Concept definition 

B.CHAIN is a biometric hardware wallet suitable for mass deployment. It reinforces the security of self-custodial mobile wallet handling digital assets and Web3 access. B.CHAIN supports most cryptocurrencies such as Bitcoin, Ether, ERC-20 tokens and many others.

B.CHAIN is easy to integrate with the existing mobile wallet application (App) and interacts through the phone’s NFC communication interface: end users just need to tap to sign a transaction! A convenient and secure way to also interact with Web3 decentralized applications (dapps).

The mobile wallet application providers maintain complete control over their user interfaces and functionalities. They design their prefered user experience while leveraging the B.CHAIN SDK that handles all communications with the card. The SDK is a set of libraries running on iOS 13.3+ and Android 8.1+.

B.CHAIN manages a Hierarchical Deterministic (HD) wallet which needs to be initialized by loading a seed generated by the App using the BIP39 standard.

The seed is securely transmitted in a binary format by the SDK to the Secure Element that stores the corresponding master private key in a protected memory. The card is then able to compute key pairs for various cryptocurrencies following the BIP32 derivation mechanism. Private keys never leave the Secure Element while public keys can be retrieved by the App to compute public addresses enabling to receive assets and check balances autonomously. Requesting a new public key from the card can be done at any time for maximum flexibility (e.g. the App supports a new cryptocurrency).

Transactions are driven by the App, this is where the users will enter all data using the comfort of the mobile wallet’s interfaces. When the transaction is ready, the users simply taps their card on the back of their phone to generate the signature. They need to unlock their B.CHAIN using their fingerprint or by entering a PIN code or both.

If the card is lost or stolen, users can quickly restore their crypto hardware wallet. The users enter the BIP39 recovery phrase they saved from the App display during wallet creation and tap a new card!

The advantages of B.CHAIN are the following: 

User friendly

Mobile friendly and easy to use: just tap to sign

Cost effective

Allows for mass deployment

Highly secure

Based on a secure certified chips

Fingerprint protected

If you lose your wallet nobody can use it