False acceptance rate (FAR) is a measure of biometric accuracy. It represents the probability that a given biometric system will accept an incorrect input as a positive match. FAR is calculated by testing known biometric templates against a large database. The nitgen algorithm was tested and shown to have a theoretical FAR of 0.0001; in other words there is only a 1 in 10,000 chance that a finger could incorrectly be identified as a positive match. By contrast, the false reject rate (FRR) is a measure of the probability that a biometric system will incorrectly reject an input as a negative match. FAR and FRR rates have an inverse relationship with one another. In other words, the more selective the biometric system is (better FAR rate), the more likely that the system will also begin to occasionally reject the correct fingerprint.