The following article has been prepared as an aid to those employers searching for a biometric system to use in the workplace. The document is intended to support employers to consider the need for a system and then to evaluate the privacy impact of different systems. The document is made to make employers aware of their responsibilities under the Data Protection Acts 1988 and 2003. The issue is the use of an employer system that may have data protection solicitude. All situations must be judged on a case-by-case basis.

Different types of biometric systems.
All biometric systems operate on the basis of the automatic identification or authentication of a person. What differs between systems is the nature of the biometric and the type of storage.

Information used to generate biometric data.
Biometric data may be created from physical or physiological characteristics of a person’s body. They are: a fingerprint, an iris, a retina, an ear shape, outline of a hand, a face, voice pattern, DNA, and body odor. Biometric data might also be created from behavioral data such as hand writing or keystroke analysis. Digitized template is produced from the biometric data. This template is then compared with the other produced when an employee tries to authenticate at a reader.

Types of biometric data.
There are three principal types of biometric data:
• Raw Images, consisting of recognizable data such as an image of a face or a fingerprint, etc.
• Encrypted images, consisting of data that can be used to generate an image.
• Encrypted partial data, consisting of partial data from an image, which is encrypted and cannot be used to recreate the complete original image.

Types of biometrics systems.
There are two main types of systems:
• Identification systems, which confirm the identity of an individual;
• Authentication / verification systems, which confirm that a biometric derived from a person who presents at a reader matches another biometric, stored on a card and presented simultaneously.

Storage of biometric data.
There are two principal methods of storing biometric data/templates;
• A card is used as templets storage. A templet is generated when a person presents at a reader, and this template is compared with the template on the card.
• Central databases store the templates on a central system which is then searched each time a person presents at a reader.