Patent attributes
A biometric authentication method is provided. In the method, identification information is collected from a user. A biometric scanner is used to scan a particular biometric characteristic of the user. If the user identification corresponds to the scanned biometric characteristic, then the scanner requests the user perform a predetermined action of a portion of the user's body. The predetermined action may be, for example, a hand gesture. The biometric characteristic is monitored while the predetermined action is being scanned. The scanner determines that the predetermined action is performed with the same portion of the user's body that was scanned for the biometric characteristic. The scanner determines if the portion of the user's body leaves the scanning area and monitors the scanning area for extraneous objects. The method provides more resistance against a replay attack.