You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: A Survey of Keystroke Dynamics Biometrics 
Chapter Title:  1.1.3. 
1. Abstract of Cited Paper (BIB001):  While online applications can provide convenience to individuals and organizations, they can pose significant remote user authentication challenges. One possible solution to these challenges is to utilize behavioral typing patterns to provide an additional layer of authentication. Such behavioral biometrics have the advantage of being revocable if compromised, unlike physical biometrics such as fingerprints. This study investigates the viability of biometric keypads. Results indicate that biometric keypads can differentiate authentic users from impostors even when a secure PIN has been compromised. Furthermore, it is shown that authentication accuracy can be improved through optimal PIN selection by avoiding correlated key combinations.

Literature Review:
Biometrics. Biometrics refers to certain physiological or behavioral characteristic that is uniquely associated to a person. This trait is highly distinctive and can be utilized for distinguishing different individuals. Physiological biometrics refers to a person's physical attribute, such as fingerprint, face, and iris. It is well known for its permanence and high uniqueness that promote high recognition accuracy. Unfortunately, it is not likely to be revoked if compromised (unable to change fingerprint pattern) BIB001 , may possibly suffer low public acceptance due to invasiveness (iris scanning), and could be unlikely practical in large-scale deployment due to implementation cost (DNA analysis). The way people do things such as speaking (voice), writing (signature), typing (keystroke dynamics), and walking style (gait recognition) are known as behavioral biometrics. Behavioral biometrics has the edge over its physiological counterpart on the ability to work in stealth mode verification. As such, minimal interaction is required during authentication process reduces invasiveness and thus promotes user acceptability. In addition, in the event if one's behavioral attribute is compromised, it is likely to be replaced (changing to a new password, thus, new keystroke print or new written signature) BIB002 . While these merits may be encouraging, they are normally inferior to physiological biometrics in terms of variability (voice changes along with aging factor) and may consequently influence verification accuracy.