Biometric key technology is the organic combination of biometric encryption technology and traditional
cryptography. Biometric key can directly encrypt data or encrypt key, with the character of portable use
and not easily being stolen, forgotten and broken. This article provides an algorithm for generating key
based on the fingerprint feature bit-strings, extracting ngerprint feature information with bit-strings
form as first step, generating key by the combination of this feature information and BCH error correcting
code secondly. Experiments show that the algorithm can generate stable key of encryption on the premise
of protecting the user's ngerprint information. It can further improve the security strength and reach
two-factors protection if the biometric key is stored in the smart card, which has certain practical value.