Typing behavior is one of the dynamic biometric characteristics
that can be used to identify people. The rhythm with which certain words or letter combinations are entered and the time intervals between the letters are among the characteristic features used for behavioral biometric recognition.
Conclusions can be drawn about keyboard entries from typing behavior, and entire entries can be reconstructed using corresponding keystroke programs. Such eavesdropping programs can be used to spy out textpasswords or the personal identification number(PIN) without the user noticing.