Biometrics for physical access control
by Csaba Körmöczi

Determining the identity of a person is becoming more and more important in our world. There are three main techniques for making such a decision. The first is knowledge-based authentication, which relies on something that a person knows, e.g. a password or PIN. The second technique is token-based authentication, which relies on something that a person possesses, such as an ID card or key. The third is biometrics-based authentication, which relies on recognising certain personal characteristics. Biometrics can be based on physical characteristics such as facial features, iris, hand geometry, hand veins, fingerprints, etc. or on personal traits, e.g. a hand-written signature, voice, etc.

AccessGuard is a physical access control system designed for high security areas. It is able to involve all the three factors of authentication methods mentioned above; it can accept PIN codes, tokens (smart cards or proxy cards), biometrics (fingerprint recognition), or a combination of these.

Fingerprint recognition and iris scanning are two of the few biometrics, which are not only considered unique, but also consistent over time, so these methods provide great reliability and accuracy. Additionally, fingerprint recognition has been used for more than hundred years, so it is safe to say that it is a proven one. The physical devices for some iris recognition systems and most fingerprint recognition systems are small enough to be integrated into almost any application.

There are a lot of emerging methods to capture a fingerprint, but Guardware is using the traditional optical scanning based on the total reflection method. This allows us to achieve high quality, high-resolution images with a larger surface than what is possible with chip sensors used for image capture. As the prism is made of hard glass, it is durable and scratch resistant, and it is not susceptible to ESD – electrostatic discharge – that may destroy or reduce the lifetime of a chip sensor.

On the surface of our optical scanners there is a special metal coating, used to detect some parameters of the object placed on the prism. Based on these parameters the system can distinguish between human tissue and fake fingers by measuring both static and dynamical electrical properties of the skin. Though a biosensor may be shooting over the target for most home applications, it is a must if the fingerprint system is used in a non-supervised environment or for access control to highly secure areas.

Naturally, the authentication of the user is one of the most important parts, but there are many other factors that make a system versatile and user-friendly. AccessGuard can be used as a device for physical access control, as an external device for an alarm system, as a device for time and attendance recording, or be combined with many other systems where reliable authentication is beneficial. The device is able to work in standalone mode, but it is also possible to install several in a networked environment. Encrypted communication is just one of the measures taken to ensure a high level of system integrity. A special script feature empowers the system administrator (or an integrator) to meet special needs and handle almost any special request (like double-key, silent alarm, anti pass-back, special greeting messages, man-trap, etc.) with these scripts. Due to the freely programmable inputs and outputs it is easy to integrate AccessGuard into an existing access control or time and attendance system.

Finding the right balance between security and comfort has always been the key success factor for biometric applications. The development of biometric systems is getting more and more competitive, as the focus of the users is shifting from primarily wanting convenience to being increasingly demanding in terms of requirements to high-end biometric solutions.