Human Keys

Human keys is an informal term for approaches that make cryptographic keys easier for people, rather than machines, to create, remember or recover. A standard private key is a long random number that no one can memorize, so wallets wrap it in more human-friendly forms: a list of words in a recovery phrase, a passphrase, a fingerprint or face scan that unlocks a key stored on a device, or a social recovery scheme in which trusted friends can help restore access. The term has no single standard meaning and is used differently by different projects. The trade-off is between convenience and security. Keys derived purely from something a person can remember, such as the "brain wallets" of Bitcoin's early years, proved easy for attackers to guess, while device-based biometric authentication depends on the hardware staying safe. Also see seed phrase.