Biometric authentication is the confirmation of someone's identity based on their personal characteristics. Biometric systems examine the user's voice, fingerprints, iris or other characteristics that are exclusive to each individual, guaranteeing that only the authorised user is granted access. Therefore, users don't have to worry about getting passwords or other more traditional types of authentication hacked. However, biometric systems have their own disadvantages, which can prove even more problematic than drawbacks of current methods of authentication.
Biometric Data Cannot Change
In case of fraud, users can change passwords or request another smart card as a security measure against future problems. However, you cannot change your fingerprints or iris in case these data are compromised. Biometric data is not secret; everyone leaves their fingerprints on everything they touch. A way to avoid fraud is supervised biometric authentication. This method works in airports or shopping malls, but there certainly cannot be supervisors at every ATM.
Biometric Systems Can't Be Used By Everyone
Disabled people, amputees and those with congenital defects can't use biometric authentication systems. For example, fingerprint authentication is not possible for people who have had a limb or limbs amputated. Airports or banks, for example, do not exclude people based on their special needs, and must introduce alternative authentication systems. However, as Mark Ryan, professor of computer security at the University of Birmingham, suggests, alternative systems may also be a cause of embarrassment to those having to use them.
Biometric systems can only operate when backed by huge databases, with records on all users' information. For instance, iris scanners take a picture of your iris and compare it with the pictures of all authorised users until they find a match --- your entry. This means that personal data are stored in records not only of established authorities, such as police or border agencies, but also of private corporations, such as Disney's four theme parks in Orlando.
The cost of developing biometric authentication systems and operating their databases is considerably higher than the cost of currently used systems. A fingerprint scanner is more expensive than a keyboard for password insertion, while the data used to safely identify the fingerprint is more complicated that a few letters and numbers.