Technical paper on BIOMETRICS

Biometrics is the science and technology of authentication by measuring the subject person's physiological or behavioral features. The term "biometrics" is derived from the Greek words bio (life) and metric (to measure). For our use, biometrics refers to technologies for measuring and analyzing a person's physiological or behavioral characteristics, such as fingerprints, irises, voice patterns, facial patterns, and hand measurements, for identification and verification purpose. So, Biometric systems can be defined as "automated methods of verifying or recognizing the identity of a living person based on a physiological or behavior characteristic". In a typical IT biometric system, a person registers with the system when one or more of his physiological characteristics are obtained, processed by a numerical algorithm, and entered into a database. Ideally, when he logs in, all of his features match 100%; then when someone else tries to log in, she does not fully match, so the system will not allow her to log in. Current technologies have widely varying Equal Error Rates - as low as 60% and as high as 99.9%.Identification and verification have long been accomplished by showing something you have, such as a license or a passport. Sometimes it also required something you know, such as a password or a PIN. As we move into a time when we need more secure and accurate measures, we begin to look at biometrics.

In this paper let us look through facial recognition and iris scan methodologies in Biometrics, how they work and their applications.

Introduction:

Imagine the ability to unlock the door, obtain money from a machine, authenticate a credit card, or even start a car with just a glance at a camera or a touch. For years now, we have seen biometrics being used in movies and on television: Mission Impossible, Sneakers, and Star Trek are just some examples. Although we may think of using biometrics as 'high-tech' and new, primitive biometrics such as height have been used to identify people since the time of the ancient Egyptians. Now biometric technology is moving into the mainstream. Not only is biometrics being used for access to high security areas, but they are now being utilized in corporate settings for network security.

Overview of biometrics:

At its most simple level, biometric systems operate on a three-step process. First, a sensor takes an observation. The type of sensor and its observation will vary by biometric type. For face recognition, the sensor is usually a camera and the observation is a picture of an individual’s face. Second, the biometric system develops a way to describe the observation mathematically; a biometric signature. The method will again vary by biometric type, but also from vendor to vendor. Third, the computer system inputs the biometric signature into a comparison algorithm and compares it to one or more biometric signatures previously stored in its database. Other system components, or human operator, then use these result(s) for other actions such as allowing computer access, sounding an alarm, etc. Although understanding the three-step biometric process is sufficient for most users, biometric systems are in reality much more complicated.

Uses for Biometric technology:


  • ATM and ticketing machines that recognize an authorized valid user (with or without card or PIN).
  • Internet access and computer log-in control.
  • Privacy systems for database and records protection.
  • Travel security systems with passport, ticket, and baggage verification.


Facial Recognition:

Although the concept of recognizing someone from facial features is intuitive, facial recognition, as a biometric, makes human recognition a more automated, computerized process. For example, public safety authorities want to locate certain individuals such as wanted criminals,suspected terrorists, and missing children. Facial recognition may have the potential to help the authorities with this mission.

The system captures faces of people in public areas, which minimizes legal concerns for reasons explained below. facial recognition can be done without any physical contact. This feature also gives facial recognition a clandestine or covert capability

As a biometric, facial recognition is a form of computer vision that uses faces to attempt to identify a person or verify a person’s claimed identity. Regardless of specific method used, facial recognition is accomplished in a five step process.


  • First, an image of the face is acquired. This acquisition can be accomplished by digitally scanning an existing photograph or by using an electro-optical camera to acquire a live picture of a subject. As video is a rapid sequence of individual still images, it can also be used as a source of facial images.

  • Second, software is employed to detect the location of any faces in the acquired image. This task is difficult, and often generalized patterns of what a face “looks like” (two eyes and a mouth set in an oval shape) are employed to pick out the faces.

  • Once the facial detection software has targeted a face, it can be analyzed. As noted in slide three, facial recognition analyzes the spatial geometry of distinguishing features of the face. The most popular method is called Principle Components Analysis (PCA), which is commonly referred to as the eigenface method. Template generation is the result of the feature extraction process. A emplate is a reduced set of data that represents he unique features of an enrollee’s ace. For distinguishing facial features,they do not use hairstyle,facial hair or other similar factors.

  • The fourth step is to compare the template generated in step three with those in a database of known faces. In a verification application, the generated template is only compared with one template in the database – that of the claimed identity.

  • The final step is determining whether any scores produced in step four are high enough to declare a match. The rules governing the declaration of a matches are often configurable by the end user.


Benefits:

  • Can recognize when user leaves PC.
  • Easy to use.
  • Equipment can be used for video conferencing as well as security.
  • Uses a 3 dimensional picture and will not accept 2 dimensional substitutes

 Drawbacks:
  • Constant camera surveillance may intimidate users.


Iris Recognition:

The iris of each eye of each person is absolutely unique. This even applies to identical twins. It is clearly visible from a distance, making it ideal for a biometric solution. No other biometric technology can rival the combined attributes of mathematical certainty, speed and non-invasive operation offered by iris recognition.

Working:

A video image of the iris of the eye is needed to produce a digitized 512 byte IrisCode® record. The image can be taken from up to 3 to 21 inches away .Once an individual is entered into the database, recognition is affirmed in just seconds. Iris recognition technology examines more than 240 degrees of freedom in the human iris to create the patented IrisCode© record.

The IrisCode™ creation process starts with video-based image acquisition. This is a purely passive process achieved using CCD Video Cameras. This image is then processed and encoded into an IrisCode™ record, which is stored in an IrisCode™ database. This stored record is then used for identification in any live transaction when an iris is presented for comparison.

Biometric Measurements

During the verification or identification process errors can occur. There are two critical measurement factors which indicate the level of accuracy, or reliability, of any given biometric. They are False Reject Rate (FRR) and False Accept Rate (FAR).

False Reject Rate (FRR)

When a biometric measurement from a live subject is compared to that subject's enrolled template and the system fails to match the two, a "false reject" event occurs. The theoretical probability of this happening, or the actual frequency with which it occurs is known as the False Reject Rate (FRR). The FRR will vary widely depending on the situation under which the biometric is used. Factors such as user co-operation, operating conditions, etc can all effect the FRR.

False Accept Rate (FAR)

There is always a possibility that the measurement from a live subject will be sufficiently similar to a template from another, different, person that a match will be declared. This second type of error is called a "false accept" event and the associated probability is called the false accept rate or FAR. The FAR achieved by a particular biometric directly reflects the fundamental power and specificity of the technology. To achieve a low FAR the biological entity measured must be absolutely unique to the individual, and the algorithm used to measure the entity must capture this uniqueness very effectively. 

The other biometric methods charted above offer scalability between security and ease of access with a trade-off between the FRR and FAR. As is shown above, IrisCode™ technology offers no scalability and is fixed to the y-axis. The FRR is much lower than that of alternative biometrics and the FAR is fixed at 0.

Benefits:
  • Low error incidence.
  • Employees know that their employers mean business when this type of security is implemented.

 Drawbacks:

  • Infrared iris scanning is perceived as intrusive.
  • Portability issues arise with remote (laptop) users.
  • Video cameras are being used, and employees may fear being ‘spied’ upon.

Conclusion

Biometric iris and facial recognition has the potential to provide significant benefits to society.Facial recognition is by no means a perfect technology and much technical work has to be done before it becomes a truly viable tool to counter terrorism and crime. But the technology is getting better and there is no denying its tremendous potential. Our Iris Recognition solutions are currently operating in a diverse range of organizations including
  • Commonwealth Bank of Australia
  • St Vincent's Hospital
  • Narita Airport in Japan
Due to the non-contact, non-invasive properties of Iris Recognition, it is the only biometric suitable for environments where hygiene is paramount or users hands are constantly occupied.


References

Technical paper on BIOMETRICS
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