Iris recognition relies on the unique patterns of an individual's iris to confirm identity. It boasts a high level of accuracy and low false acceptance and rejection rates, making it highly resistant to being fooled or replicated. This makes it suitable for high-security environments. Fingerprint recognition, while unique, suffers from higher false acceptance rates than iris recognition and can sometimes be replicated using sophisticated methods. Keypads rely on a 'something you know' factor and can be easily compromised if the pin is shared or guessed. Voice recognition has a higher risk of false acceptance and can potentially be spoofed with high-quality recordings or advanced voice synthesis.