(fâls ri-jek´shun) (n.) In biometrics, the instance of a security system failing to verify or identify an authorized person. Also referred to as a type I error, a false rejection does not necessarily indicate a flaw in the biometric system; for example, in a fingerprint-based system, an incorrectly aligned finger on the scanner or dirt on the scanner can result in the scanner misreading the fingerprint, causing a false rejection of the authorized user.
The false rejection rate, or FRR, is the measure of the likelihood that the biometric security system will incorrectly reject an access attempt by an authorized user. A system’s FRR typically is stated as the ratio of the number of false rejections divided by the number of identification attempts.
Compare to false acceptance.