Facial recognition is an efficient security measure that does not require physical contact with the device and can work well even in low-light conditions due to infrared cameras or other advanced sensors. While fingerprint scanners are common and secure, they require physical contact. Iris scanners are also secure but may have functionality issues in low light. Voice recognition does not require physical contact but can potentially be less secure due to the possibility of voice imitation and typically does not perform well in noisy environments.