Off-Chain Multi-Sigs Powered by Threshold Cryptography
User keys are split via a threshold scheme into “shares” secured on a mixture of authentication methods and user devices. A threshold number of shares are required to gain access to the key.

Onboarding thousands of users through Web3Auth
Binance chain Extension Wallet (BEW) introduced a new seamless and secure user onboarding process through Web3Auth in early 2021 and has since onboarded hundreds of thousands of users into the BEW wallet.

Designed with a simple and straightforward user experience for mainstream users, the onboarding includes OAuth logins, key management that reduces account loss while retaining the non-custodial guarantees that the decentralized ecosystem requires.

拓展学习：
例如，对于三选二 (2/3) 设置，我们为用户提供三种共享：ShareA、ShareB 和 ShareC。

ShareA存储在用户的设备上：实现是特定于设备和系统的。例如，在移动设备上，共享可以存储在通过生物识别技术保护的设备存储中。
ShareB在 Web3Auth 的 Auth 网络中进行管理和拆分，由用户拥有的 OAuth 登录提供程序访问。
ShareC是一个恢复共享：由用户保留的额外共享，可能保留在单独的设备上，下载或基于具有足够熵的用户输入（例如密码、安全问题、硬件设备等）。
与现有的 2FA 系统类似，用户需要证明拥有至少 3 (2/3) 股中的 2 股，才能取回他的私钥。

https://www.npmjs.com/package/shamirs-secret-sharing
https://en.wikipedia.org/wiki/Shamir%27s_secret_sharing
https://medium.com/toruslabs/how-binance-chain-extension-wallet-removes-seedphrases-with-web3auth-40cd527fcfaf