What does an increase in the Crossover Error Rate (CER) signify for a biometric authentication system?

An increase in the Crossover Error Rate (CER) for a biometric authentication system signifies reduced accuracy. The CER represents the point at which the false acceptance rate (FAR) and the false rejection rate (FRR) are equal. As the CER increases, it indicates that the system is more likely to either incorrectly accept an unauthorized user or incorrectly reject an authorized user. This balance means that the system's reliability in distinguishing between authentic and non-authentic individuals is compromised, thereby leading to reduced accuracy in the biometric authentication process.

In biometric systems, a lower CER is typically desired as it signifies a higher level of precision in correctly identifying true matches while minimizing the incorrect matches. Thus, an increase in CER reflects a decline in the system's overall effective performance concerning accurate verification and identification.