A technique of identity authentication through the "who are you" method, such as measurable physical or behavioral biometrics. Biological characteristics refer to the only physiological characteristics or behavior patterns that can be measured or automatically identified and verified. Use a sensor or scanner to read the biometric information, compare the read information with the user's feature information in the database, and if they are consistent, the authentication is passed.

Biological characteristics are divided into physical characteristics and behavioral characteristics. Physical features include: voice print (d-ear), fingerprint, palm shape, retina, iris, human body odor, face shape, blood vessels of hand and DNA. Behavioral features include signature, pronunciation, walking gait, etc. At present, some scholars classify retina recognition, iris recognition and fingerprint recognition as advanced biometric technologies. Palm recognition, face recognition, voice recognition and signature recognition are classified as secondary biometric technologies; Vascular texture recognition, human body odor recognition and DNA recognition are classified as "abstruse" biometric technologies.

At present, we are most exposed to fingerprint identification technology, and its application fields include access control system and micropayment. Some mobile phones and laptops we use every day already have fingerprint recognition function. Before using these devices, you don't need to enter a password, just press your finger on the scanner and you can enter the operation interface of the devices, which is very convenient and difficult for others to copy.

The security risk of biometric identification is that once the biometric information is stolen in database storage or network transmission, the attacker can carry out some kind of identity deception attack, and the target of the attack will involve all devices that use biometric information.