In science fiction movies, computers have been checking handprints, listening to voices, or scanning eyes to ensure that only authorized personnel can access systems for years. But such security checks, called biometric systems, are no longer limited to Hollywood reels; a small but growing number of organizations are deploying systems that compare an individual’s biological characteristics (such as face, fingerprints, or voice) against others before granting access to secure areas.

This technique exploits the fact that biological characteristics are singular, unchanging, and difficult to lose, transfer, or forget. Consequently, they tend to be more reliable, user friendly, and secure than systems that rely on passwords.

While offering many benefits, the technology still has its faults. The various techniques to ensure proper identification are still emerging and may be too unreliable for certain organizations. Also, biometric techniques can be costly, with entry level systems hovering in the $50,000 to $100,000 range, so the technology is still in the pilot phase and probably a few years from working its way into the educational mainstream.

Still, some schools already have implemented biometric systems to help keep their students safe. The Harriet Beecher Stowe School, a Chicago, Ill., elementary school with 1,500 students in grades K-8, has installed a fingerprint-checking system to give students secure access to the school’s two buildings.

The school is in a high-crime area, and students often travel between the two buildings during the day. The school had relied on a key system to ensure that entrances between the buildings were properly secured. Teachers were issued keys and used them as they moved from building to building. But “if one teacher lost a key, we had to collect all 100 and have the locks changed, a process that was expensive, frustrating, and time consuming,” said Charles Kyle, the school’s principal.

One of the faculty’s spouses worked at Chicago’s O’Hare airport, where a biometric fingerprinting system from Identix Corp. of Sunnyvale, Calif., controls access to doors so individuals can’t sneak onto planes or put items in cargo bins. The school hired SecurCom Inc., a Twin Lakes, Wis., systems integrator that works closely with Identix, to replace its key system with the fingerprint access, which became operational in May.

“I feel relieved knowing there aren’t hundreds of keys floating around the school,” Kyle said.

Characteristics of biometric solutions

Each biometric technology has its own unique characteristics, procedures, and degree of accuracy. But the process of capturing, extracting, storing, and matching biometrics is similar for each. An individual presents his biometric data to a capture device, which collects the personal information and forwards it to a software algorithm that extracts the unique characteristics and creates an identifier.

When the person wants to access the system, he presents the identifier. If it matches, he gains access to the system. To ensure that a department doesn’t have to enroll identifiers at every workstation, they’re often stored centrally—so a user can log in at any fingerprint-reading device on a network, for example.

Matching is seldom black and white, however. Due to environmental and other conditions present at the time of data capture, no two biometrics are ever identical. Typically, a matching algorithm yields a score for each match attempt and then compares it to a company-established threshold.

If the threshold is set low, it becomes easier for an unauthorized person to be falsely accepted. If the threshold is set high, an authorized person might be falsely rejected.

“Organizations have been concerned about accuracy issues, but biometric technology has been improving—so the matching level should be adequate for most,” said Harry Wilkinson, president of SecurCom.

Fingerprint authentication devices, like the one at Harriet Beecher Stowe School, are the most commonly understood biometric system. Once a user’s digits are scanned, he or she no longer has to worry about entering security codes or passwords.

Facial recognition offers the least-intrusive approach to authentication—in fact, users may not even be aware that they’re being identified. These systems can continually monitor the front of a computer for the presence of valid users, unlock the system when they sit down, then immediately re-lock the system again when they stand up. However, facial systems sometimes have difficulty telling some people apart, particularly identical twins, so their use has been limited.

Voice-recognition systems rely on common hardware components, so they are the simplest systems to deploy. A company or school district may only need to add a microphone to install such a system. In fact, certain systems can use the telephone for authentication, so no additional equipment is needed.

However, voice recognition systems are not highly reliable. In certain cases, a system’s settings might have to be tuned several times until it adapts to the user. Consequently, this approach is only used in environments where the potential loss from fraud is not too high.

Barriers to acceptance

Since it is an emerging area, biometric security still must overcome some barriers before attaining widespread acceptance. Perhaps the biggest is that these products are too expensive for general use: Prices typically run in the four-digit or five-digit range per device. But there have been positive pricing trends. “Three years ago, it was impossible to build a biometric security system with off-the-shelf components; now, it’s fairly straightforward,” said SecurCom’s Wilkinson.

Price reductions coincide with the adoption of low-cost standardized components: digital signal processors, random access memory, and cameras, as well as new methods of mass production for custom components, such as plastic optics.

While the prices are falling, they are still out of reach for most school districts. Voice recognition systems are the simplest and cheapest systems to deploy. Prices for fingerprinting systems have been falling, but facial recognition systems costs are still high.

The Harriet Beecher Stowe School was able to put its system in because the vendors installed it for free. “We think a lot of schools will be interested in biometric security system and see the Harriet Beecher Stowe work as an investment in our future,” Wilkinson said. The company planned to meet with the Chicago School Board during the summer to talk about expanding use of the biometric security system to other city schools.

Other Illinois school districts have expressed interest in such systems as well. Kyle, who became principal of the Harriet Beecher Stowe School in the fall of 1998, had previously worked at a suburban elementary school where the parents had voted to spend money to secure buildings more tightly.

“Some administrators ignore security issues because they’re afraid the talk about potential problems will alarm parents,” he concluded. “My experience has been just the opposite: Parents know what may happen at school and feel better when they see administrators taking steps to avoid them.”