Biometric Technology is Security




Violeta C. Hernandez

University of Minnesota, Morris

600 E 4th ST Apt.D3

(320) 589-6585

hernandv@morris.umn.edu

 

 

 

 

 

 

ABSTRACT

Everyday actions are becoming less likely to be handled by paper and pencil or face-to-face.  Now, electronic transactions are the demand for high-level accurate user identification and authentication.  Biometric technology has made it easy for this great demand of transaction to be affordable and user-friendly.  This paper will highlight some of the transactions that use Biometrics and technologies used for the process of some of the transactions. 

Keywords

Fingerprints, iris, biometrics, market, and optical.

1.     INTRODUCTION

As the world grows so does technology.  As crime increases so do ways of using technology for security.  Security is starting to be based on technology systems that have been developed to identify fingertips, irises, facial features, hands, etc. These identifiers can be scanned with technologies that use biometrics.  Biometrics is the automatic measurement of physical or behavioral aspects of the human body for authentication or identification, and it is a rapidly growing industry.  Biometrics’ ease of use, accuracy, reliability, and flexibility are quickly being establishing as the premier authentication technology [7]. 

2.     IDENTIFICATION

People have unique body features that cannot be replaced or lost, like passwords or cards, and that can be used for identification.  If the body features are the user to a system or “password”, it will never be forgotten or stolen.  Confirming identity by unique physical attributes greatly reduces the chance of a successful user to be impersonated.  Biometrics can be used in identification and verification modes.  An identification mode is where the biometrics system identifies a person from the entire enrolled population by searching a database for a match.  A verification mode is where the biometrics system authenticates a person’s claimed identity for her/his previously enrolled pattern [7].  

 

Figure 1. Characteristics of the finger  [3].

3.     FINGER-SCAN BIOMETRICS

3.1     What Makes the Fingertip Unique

 

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The uniqueness of the fingertip consists of one of three distinguishing patterns, which are loop, whorl/swirls, or arch.  There are some fingerprints that contain more than one of these patterns.  The loop pattern consists of ridges that start from one side of the finger and then reach the core point (normally in the middle of the print) of the finger and loop back to the same side.  In the whorl pattern, some ridges form concentric circles around the center of the finger, and the remainder shape themselves around these circles.  The pattern that forms an arch over the center begins at one side of the finger and end at the other end of the finger [2, 3].  

3.1.1     Types of ridges

The following are characteristics of different kinds of ridges:  ridges known as dots are very small, island ridges are slightly longer than dots which occupy a middle space between two temporarily divergent ridges (ponds or lakes are empty spaces between two temporarily divergent ridges), branches are multiple ridges that are separated by a point called bifurcation, bridges are small ridges joining two longer adjacent ridges, and crossovers are two ridges which cross each other [2, 3]. 

3.1.1.1     Spaces Between Ridges

The point at which a ridge stops is called a ridge ending.  The bifurcation is the point where a ridge splits into multiple ridges, called branches.  The core is the inner point, approximately the center, around which loops, whorl/swirls, or arches center (see Figure 1) [2,3].  

3.2     Processes used in Scanning

Obviously, since no two fingerprints are alike it is essential to find mechanisms that develop processes that can find the uniqueness of fingerprints.  Fingerprint recognition is not an easy task when the area of the fingertip is small and hard to measure.  Clear ridges patterns are hard to come about without the use of increasingly complex mechanisms that capture the fingerprint image with sufficient detail and resolution.  Optical, silicon, and ultrasound technologies are used today to simplify the process of scanning [3, 5].

3.2.1.1      Optical Technology

This technology is the oldest, inexpensive, and most implemented.  It can withstand temperature fluctuations and is widely used.

The process includes placing the finger on a coated platen that is usually built of hard plastic.  In most devices, a charged coupled device (CCD) converts the image of the fingerprint, with dark ridges and light valleys, into a digital signal. The brightness is either adjusted automatically (preferable) or manually (difficult), leading to a usable image [3].

Yet, even though these advantages are very clear and distinct, particularly when there is a lot of mechanical mishandling, the drawbacks include the insufficient size of the platen (must be of sufficient size to achieve a quality image) and latent prints.   Harsh latent prints (leftover prints from previous users) can cause two sets of prints to be superimposed. Also, the coating and CCD arrays can wear with age, reducing accuracy [3].

Although most companies, such as Identicator and its parent company Identix jointly with Motorola, utilize optical technology, more are moving on the road to silicon [3].

3.2.1.2     Silicon Technology

Silicon or chip technology is being proposed as a means of identifying the fingers’ ridges and spaces as well.  This technique presents an opportunity to devise and implement highly repressive identification schemes.

“The silicon sensor acts as one plate of a capacitor, and the finger is the other,” [3].  The sensor measures the temperature difference of the friction of the, “ridges generating more heat than the non-touching loops,” as they slide along the silicon surface [12].  The capacitance between platen and the finger is transformed into an 8-bit grayscale digital image.

Since the chip is comprised of discreet rows and columns, which are between 200-300 lines in each direction on a 1 cm X 1.5 cm wafer, it can produce exceptionally detailed image quality, using less surface, than optical [3].

“Authen Tec’s technology for fingerprint identification is based not on optical or capacitive sensors.  Instead, the FingerLoc sensor is a silicon chip that includes a sensing array.  The sensor ignores external, damaged skin and reads the secondary layer, where prints are found in pristine condition.  To read the print, an array of tiny antennas reads the thin layer of saline liquid that resides between the living skin and the dead skin on a person’s fingertip,” [4].

Major companies, such as Infineon (the semiconductor division of Siemens), Sony, and Veridicom (a spin-off of Lucent) the leader in silicon technology, have recently delved into the silicon field market [3].   

3.2.1.3     Ultrasound Technology

Ultrasound technology, though considered the most accurate of the finger-scan technologies, is not yet widely used. It transmits acoustic waves and measures the distance based on the impedance of the finger, the platen, and air. Since ultrasound has the capacity to penetrate dirt and residue on the platen and the finger, it takes away the demand for optical technology [3].

By using the products from Ultra-Scan Corporation (USC) the strength of optical and silicon technologies are combined.  The combination consists of large platen size and ease of use and the ability to overcome sub-optimal reading conditions. [3].

4.     IRIS-SCAN BIOMETRICS

4.1     What Makes the Iris Unique

The most familiar characteristics that are unique to the iris are the trabecular meshwork (permanently formed by the 8th month of gestation), a tissue that gives the appearance of dividing the iris in a radial fashion.  The other characteristics that are easier to capture because of their clarity to the human eye are rings, furrows, freckles, and the corona [8].

4.2     Processes used to Identify the Iris

Characteristics that are unique are expressed simply by iris recognition technology converting these visible characteristics into a 512 byte IrisCode(tm), a template stored for future verification attempts.  512 bytes is a fairly compact size for a biometric template, but the quantity of information derived from the iris is massive.  From the iris' 11mm diameter, Dr. Daugman's (a developer of the iris recognition concept in 1990) algorithms provide 3.4 bits of data per square mm.  This density of information is such that each iris can be said to have 266 unique "spots".  This '266' measurement is cited in all iris recognition literature; after allowing for the algorithm's correlative functions and for characteristics inherent to most human eyes, Dr. Daugman concludes that 173 "independent binary degrees-of-freedom" can be extracted from his algorithm – an exceptionally large number for a biometric [8].  (Note:  Dr. Daugman’s algorithm is illustrated in the following section.)    

Figure 2.  Caption of the eye by the monochrome camera [8].

4.2.1.1     Algorithm

First a monochrome camera, which uses both visible and infrared light, is positioned no more than three feet from the eye.  Then the algorithm narrows in from the right and left of the iris to locate its outer edge (see Figure 2).  The algorithm then uses two-dimensional Gabor wavelets to filter and map segments of the iris into hundreds of vectors.  The wavelets of various sizes assign values drawn from the orientation and spatial frequency of selected areas, referred to as the “what” of the sub-image, along with the position of these areas, referred to as the “where.”  The “what” and “where” are used to form the IrisCode.  Data from the wavelet filtering and mapping is represented by hexadecimal data returned instead of images.  Portions of the top of the eye, as well as 45 degrees of the bottom, are unused to account for eyelids and camera-light reflections (see Figure 3).  The iris recognition algorithm recognizes the changes and size of the pupil.  The algorithm can also detect reflections on the eye and contacts on the eye [8].

Figure 3.  This caption takes away the eyelids and camera light [8].

4.2.1.2     Accuracy of Algorithm

The IrisCode constructed from these complex measurements provides such a tremendous wealth of data that iris recognition offers levels of accuracy orders of magnitude higher than other biometrics (see Table 1) [8].  (Note:  The Equal Error Rate is the point at which the likelihood of a false accept and false reject are the same.) 

Table 1.  Statistical representations of accuracy

Odds of 2 different irises returning a 75%match

Equal Error Rate

Odds of 2 different irises returning identical

 

1 in 1016

1 in 1.2 million

         1 in 1052

 

 

 

 

 

 

The algorithm can also account for blocking of the iris: even if 2/3 of the iris were completely obscured, accurate measure of the remaining third would result in an equal error rate of 1 in 100,000 [8].

5.     OTHER BIOMETRIC TECHNIQUES

Not only do biometric technologies include finger and iris scanning but also other techniques.  These techniques are facial, retina, hand, voice, and signature scanning that are also security developments that capture the interest of the market.

Facial scan technology uses distinctive features or characteristics of the human face.  Facial scan is in fields as varied as physical access, surveillance, home PC access, and ATM access.  This technology is high among users because of ATM applications.

Figure 4. A look at the back of the human eye [13].

 

Retina scan technology along with iris scanning is very accurate and therefore very demanded for authentication.  The difference between retina and iris scanning is that retina scan uses a more invasive technique, which looks for blood vessel patterns behind the human eye (see Figure 4).  Since it is among the most difficult to use, patience is needed to read film portrayals of retina scanning.  This biometric technology is exclusively demanded in high-end security applications, such as military installations, power plants, etc.

Hand scan (hand geometry) though not the most accurate, dominates an important segment of the biometric industry.  Hand scan is read by taking the measurements of fingers, joints, and knuckles of the human hand.  This biometric technology resolves low to mid security problems in processes such as access control, time, and attendance in the work place or other industries.

Voice scan (voice / speaker verification) recognizes distinctive qualities of a person’s voice.  Voice scanning is used in areas such as call centers, home imprisonment, banking, account access, home PC and network access, and many others.

Signature scan (Dynamic Signature Verification) though not broadly demanded, is used to authenticate documents.  Stroke order, speed, pressure, and other factors that deal with signing are read by this biometric technology.    

6.     THE MARKET ON BIOMETIRCS

Low cost and accuracy is what flashes in the eyes of the business world, and biometrics authentication is what makes the light for the market.  Biometrics solutions are used successfully in few fields as e-commerce, network access, time and attendance, ATM’s, corrections, banking and medical record access.  Authentication security is becoming more and more vital in the marketplace.  “Some biometric techniques are affordable and viable even now.  Fingerprint recognition hardware can be deployed for $200 to $300 per desktop,” [1].

Also, with growing customer demands, and increasing federal security requirements, companies are racing with each other for the best releases of biometric devices.

Leading biometric companies such as Idextix released a new secure-transaction service called itrust, “which is being funded with $3.75 million from Motorola Ventures, the handset manufacture’s venture capital arm,” [4].

6.1     Finger-scanning in the Market

Finger scanning biometrics is the most implemented and demanded application (see Figure 6) in the market.  Its great demand is duded to its low cost and high accuracy.  For example, “small cost of these devices can provide secure access to desktop PCs, laptops, the Web, and most recently, to mobile phones and palm computers,” [12].  The illustration given in Figure 5 gives a good visual of the association of the finger recognition’s cost and accuracy to other techniques’ cost and accuracy (see Figure 5) [11].  Therefore, because of its low cost and performance more security systems are using finger scanning.  

The Immigration and Naturalization Service’s (INS) Passenger Accelerated Service System (INSPASS) uses biometrics for traveler verification, which makes it easy to transfer goods and people between countries.  The CANPASS is the Canadian version of INSPASS and uses fingerprint biometrics for recognition at the Vancouver International Airport [5].

In July of 1991, Los Angeles County in California installed the first Automated Fingerprint Image Reporting and Match (AFIRM) in order to reduce fraudulent and duplicate welfare benefits.  “Within the first 6 months of use, the county saved $5.4 million dollars, and the savings have been growing ever since,” [5].  AFIRM became a statewide operation in California some time in 1997. 

6.2     Iris-scanning in the Market

Since the concept of Iris scanning is owned by Drs. Leonard Flom and Aran Safir along with Dr. John Daugman  who developed the recognition algorithms, does not face any competition.  Companies, such as OKI, LGS, NCR, and Diebold, who wish to use its technology, need to be licensed [14].  Though iris scan is the most expensive technology, more companies have integrated iris scan technology into ATM’s because of its very high accuracy (see Figure 5) [11].  High performance means high security for systems such as ATM’s, which are used by people more and more for transactions of money.       

The industry focus on iris scanning has grown tremendously on areas with true revenue production.  “The release of their PC Iris identification product, designed for home PC use, could significantly realign the biometric industry as it stands today,” [14].  The release of an affordable, reasonably sized iris recognition device may seize market share from more biometric vendors in other disciplines [14].       

Even with the interest of iris scanning by companies, users have been reluctant to use the technology (see Figure 6). “Iris and retina scans are unlikely to gain acceptance due to people’s natural protectiveness of their eyes,” [1].

Figure 5.  “This figure roughly illustrates a comparison between cost and accuracy.  The cost represented here is a typical incremental investment needed for acquiring a commercially available biometric sensor and for implementing and identity authentication system.  The most costly technologies aren’t necessarily the most accurate,” [11].

7.     CONCLUSION

There is great demand for the fast, tremendously accurate authentication that biometric systems can provide.  Continued improvements in technology will bring increased performance at a lower cost, fueling the continued growth in operational systems.  Biometric authentication, however, is not a magical solution that solves all security concerns.  A complete systems approach that addresses a variety of security, functional, operational and cost consideration is always necessary.  The growth will place greater demand on both biometric system developers and they need to work together to develop testing standards.

Figure 6.  Sample chart from biometric market report 2000 [13].    

8.     REFERENCES

[1]     Connolly, P.J.  Future security may be in the hands, or eyes, of users- By eliminating the need for user passwords, biometrics will tighten networks and save big IT money.  InfoWorld, 22 (InfoWorld Media Group, Inc. Oct. 2000), 94.

[2]     Finger and Faces: A Closer Look.  PC Magazine, (Ziff-Davis Publishing CO, April 1999), 199.

[3]     Finger-Scan Technology.

http://www.finger-scan.com/finger-scan_technology.htm.

[4]     Goldman, Chris.  Biometrics Break on Through.  Wireless Review, 17 (A PRIMEDIA CO, Sept. 2000), 11.

[5]     Government Applications and Operations. http://www.biometrics.org/REPORTS/CT.

[6]     Hand-Scan.com Home.                                http://www.hand-scan.com.

[7]     Hearing on Biometrics and the Future of Money.                              http://www.house.gov/banking/52098jd.htm.

[8]     Iris Recognition: The Technology.                  http://www.iris-scan.com/iris_technology.htm.

[9]     Michaud, Kevin.  Fingerprint ID system uses image DSP.  Electronic Engineering Times, (CMP Media, Inc. November 1999), 130.

[10]  NEWS from Subcommittee Chairman Michael N. Castle.  http://www.house.gov/banking/52098cas.htm.

[11]  Pankanti, S., Bolle, R. M. and Jain, A.  “Biometrics: The Future of Identification,” IEEE Computer, (Feb. 2000), 46-49.

[12]  Phillips, P. J., Martin, A., Wilson, C. L. and Przybocki, Mark.  “An Introduction to Evaluation Biometric Systems,” IEEE Computer, (Feb. 2000), 56-63. 

[13]  The “Biometrics-Scan.com” Sites                                              http://www.iris-scan.com/Dash-scan.com.htm.                           

[14]  The Iris Recognition Industry Today.              http://www.iris-scan.com/iris_recongnition_today.htm.