With ShadowTrack's service, parolees or others on restricted leave receive automated phone calls at random times of the day. During the call, they are asked to answer questions. The software, which uses voice authentication software from Nuance Communications, then compares the responses against a voiceprint in its records.
If the voice matches, the home incarceration continues. If the person who responds ("Yes, this is Billy Ray. My favorite color is yellow") sounds more like a 12-year-old using a deepened voice, the system automatically alerts the authorities.
"It is about one-third of the cost of traditional ankle transmitters," ShadowTrack CEO Robert Magaletta said. "We use it for probation and parole; we use it for juvenile monitoring, truancy. It is very popular with drug courts."
And it's not just for criminals either. Banco Bradesco, Brazil's largest private-sector bank, has installed Nuance's Verifier authentication software as part of its consumer e-banking and bill-payment system. In Canada, a large bank and a telecommunications carrier are each currently conducting beta tests, said Larry Heck, vice president of research and development for Menlo Park, Calif.-based Nuance.
Authentication technology--hardware and software systems that allow an individual or business to precisely identify someone--is a technology whose time has come. The question now is whether society wants it.
Although smart cards--plastic cards that carry password and identity data, for digital authentication--have taken off in parts of Europe, most people still rely on passwords to gain access to bank accounts and computer databases.
Passwords, however, can be stolen. With smart cards, the likelihood of a scam is reduced, because sensitive data travels in an encrypted fashion in an exchange between two machines. To break into an account, you'd have to steal someone's PC or smart card.
Authentication technologies are much more advanced than one would think.
Authentication technologies are much more advanced than one would think. The key factor in Verifier is that it analyses the vibrations created in the human vocal tract, according to Nuance's Heck.
In short, the shape of a person's vocal tract determines the timbre and resonance of the voice, and everyone's vocal tract is fairly distinct in shape and size. Thus, just as B flat on a French horn and a piano sound different, different vocal tracts will produce particular sounds. Identical twins can pass for each other, but in most cases, imposters fail.
"In most cases, imitators they tend to focus on the gait or timing of the speech. They aren't altering the physical mechanism of speech, which is the vocal tract," Heck said. "Rich Little has a physical apparatus that is fixed, and there is nothing you can do about it."
Voiceprints can also rely on small chunks of data. Nuance takes samples at different energy (or decibel) levels and then breaks up the soundtrack into 30-millisecond segments. A voiceprint can be recorded in between two and eight seconds, with a total of two to four utterances. The most variable factor in the system is the quality of the phone line, according to Heck.
A study from the U.K.'s National Physical Laboratory found that voice authentication, for purposes of identification, had a lower failure rate than methods using fingerprints or facial recognition, Heck noted. Onlyscored better.
"People are overoptimistic on what you can do with fingerprints," Heck said.
Hard identification, of course, gives people the creeps.
Microsoft's Next Generation Secure Computing Base (NGSCB), formerly known as, which creates secure data vaults on PCs, cuts down on fraud because identity is hardwired into a PC, according to the software maker. Critics, however, charge that it will allow media companies to prevent consumers from sharing music or video.
The technological basis of Verifier, in fact, came from research on voice authentication Heck conducted under a grant from the National Security Agency, the CIA, the U.S. Marine Corps and the Defense Advanced Research Projects Agency (DARPA) in the mid-1990s, according to Heck.
"The first idea was over-the-phone voice authentication--'Is it Bob or not?'" Heck said. "They wouldn't say what it was for."
Another slightly unsettling part is the cost-savings angle, at least to me. Customers give up some privacy, but companies and governments cut their costs.
Some jurisdictions have even turned it into a way to make profits. "In nine out of ten cases, they (offenders) pay for it themselves," said ShadowTrack's Magaletta.
On the other hand, ATM cards have allowed banks to cut costs and more easily collect data on customers--and no one would even think of eliminating them.
A source who once had to wear an ankle bracelet (the result of grad school buffoonery gone awry) said he worried that the ShadowTrack system could compromise privacy--but said it could also have advantages. (He met his future wife while doing a home stay, complete with ankle bracelet, at a friend's house. He spent the whole weekend sporting the Franklin Roosevelt blanket-on-the-legs look.)
If you'd like to talk more on this issue, you can reach me at home.