**2.1 Types of multi-biometric systems**

The multi-biometric system can be (**Figure 3**) (a) a multi-sensor system that allows obtaining data from various sensors using one biometric feature, (b) a system with multiple algorithms processing a single biometric feature, (c) a system consolidating multiple occurrences of the same body trait, (d) a system using

**Figure 3.** *Types of multi-biometric systems.*

multiple templates of the same biometric method obtained with the help of a single sensor, and (e) a multimodal system combining information about the biometric features of the individual to establish his identity [2–4].
