False acceptance rate

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The false acceptance rate or FAR (also false acceptance rate or rate false accept, rarely rate false acception or false acceptance ratio ) is a concept of biometrics . It describes the probability or relative frequency with which a security system grants access even though the person has no access authorization . In medicine and in connection with the detection of e.g. B. computer viruses or spam are also referred to as the false positive rate (cf. false positive ).

The FAR is a security feature. It describes the errors of the 1. type of detection test.

The false match rate (FMR) is often used synonymously with FAR. When calculating the FMR, however, access attempts that are rejected from the start due to poor image quality, for example, are not taken into account. Thus, the FMR stands for the acquisition attempts, while the FAR depicts the acquisition transactions.

The FAR is generally regarded as the most important criterion for the quality of a biometric solution, but on the other hand it cannot be specified globally, as it depends on many different internal and external factors. A typical value is e.g. B. a FAR of or . This means that on a statistical average, one out of 100,000 unauthorized access attempts will lead to success.

In the identification , the FAR increases rapidly in contrast to the verification , since each access attempt is faced with not just one, but many references. Biometric systems have to take these different requirements into account.

Expressiveness

In connection with the FAR there is always the false rejection rate (FRR), which indicates the probability with which an authorized person will be rejected. In contrast to the FAR, which is to be understood as a security feature, a small FRR represents a convenience feature. The smaller the FAR, the larger the FRR and vice versa. However, there is no formula for calculating one value from the other. Both values ​​must be determined through tests.

In order to be able to make reliable statements about a biometric system and to find a suitable compromise between security and convenience, both details would be necessary. For marketing reasons, however, the singular specification of a particularly small FAR is often preferred.

See also

Web links

Individual evidence

  1. Classification of terms in biometrics. Christoph Busch Harmonized Biometric Vocabulary. Retrieved February 5, 2015.