Biometric Systems in use by Miller

Understanding biometric security systems and their applications

Biometric security systems, put simply, are one which recognises a human being though their physical make-up and behaviour. It can then use this information to allow them access to a physical, or digital, location. Biometric security systems come in many different varieties.


The longest-running method of biometric identification is that which uses a person’s fingerprints. It has long been used in criminal investigations, since the patterns of ridges and furrows in a person’s fingertip is unique to them. In biometric systems, a special scanner is used in order to identify the person who wishes to gain access.

The main drawback to this method of identification is that it is less accurate than others. The sensor will also sometimes fail to recognise a print because of the build-up of grime left by the impact of thousands of dirty fingertips. That said this is one of the cheapest methods of biometric identification and one whose speed and accuracy is improving every year.


A vein scanner will identify a person by the arrangement of veins in either their palm, fingers, or the back of their hand. It does this by bombarding the hand with infra-red light and thereby exciting the haemoglobin in the blood. The resulting pattern can then be detected using a special scanner. It is the latter phase of this process which is the most costly – the technological requirements put it beyond the reach of most small businesses.

Hand Geometry

As well as scanning the vein structure of hand, users can also be identified by the shape of their hands. The main downside of this method is that the geometry of a given human’s hand is not unique. It is therefore best used in conjunction with other biometric devices in order to better verify a person’s identity.


Despite what one might first assume, the wearing of visual aids, like glasses and contact lenses, does not impede the efficacy of an eye scanner. Almost everyone can use an iris-scanner.

An Iris scanner consists of a high-definition camera which photographs the iris and special software which can use the image to identify the user. This renders it distinct from older forms of eye-based biometrics, which scan the retina.

One thing which might be seen as a negative factor of the iris scanner is the psychological effect it has on the users – it can be daunting to have to put your eye in front of a strange device. This fear is one which causes many businesses to hesitate before parting with the considerable sum necessary to acquire such a system.


A facial recognition system typically employs several cameras in order to discern the relative position, size and shape of a person’s facial features and thereby determine their identity. Newer systems can attain superior accuracy by forming a three-dimensional image of a person’s face. The unique geometry of a person’s face – the contours of a person’s eye sockets, nose and cheeks – can be used to paint a more detailed and more accurate picture of their face.

A facial recognition system is not intrusive, as it is contactless. This fact, combined with the system’s accuracy, has made it especially popular. However, these benefits come at a price. Facial recognition systems are a great deal more costly than the other technologies available. Such systems are therefore typically only employed in situations where the need for security is the greatest.

Advantages of Biometrics

Whilst we have already examined some of the various merits of the various methods of biometric authentication, it is worth also discussing why biometrics may be better (or worse) than other methods of access control.

More secure than card/pin systems

The main advantage of employing a biometric system is that it is more secure than one based on card or pin and still more secure than one based on a mechanical lock and key. These more traditional forms of identification can be subverted. A PIN can be communicated verbally, while a card can be passed from one person to another. This creates scope for theft and for corruption.

An employee might pass their card to someone in order that they be ‘clocked in’ when they are not yet present. This prevents an employer from being able to identify those who are persistently late – and in some cases allows people to avoid turning up altogether.

Another danger lies in the ability of a potential thief from entering the premises using an employee’s card. This card might have been stolen, or it might have been willingly passed on. It makes little difference in the end: a security breach has occurred that could not have done so under a biometric system.

Keeps track of who is coming and going

As well as preventing unauthorised people from entering the premises, an electronic system of user access can keep a detailed and precise log of exactly when users are entering the premises and which areas they are entering into. This will aid matters in the event of any misconduct. If some damage should occur in a building, for example and there is only one person there, it will be fairly simple to prove that person’s guilt.

Easy to use

Another huge boon of a biometric system is that it is, essentially, fool-proof. While a password can be forgotten and a set of keys lost, there is very little chance that someone might misplace a finger or an eyeball.

Disadvantages of Biometrics

The main drawback of the systems thus far discussed can be their cost. Another is their relative slowness. This might be problematic if a huge volume of traffic needs to be authorised in a short space of time; it would, after all, not do to have a half-hour queue to get into a building every morning.

Another disadvantage of biometric systems is that they do not cope well with adverse environmental conditions. A fingerprint scanner will, for example, not operate correctly if the lens becomes dirty. As such, such devices are better suited to being contained within a cabin, when used in outdoor environments – particularly those in which extreme weather conditions are at all probable.