Posted: March 11th, 2023

side law

500 words

Week 1 Discussion Forum 2: Should we rely on bio-metrics for identification?

Read Sidebars 2-10 and 2-11 on pages 65-66 in our text. They discuss the state of bio-metrics in identification and authentication. What is your opinion of our reliance on fingerprints for identification of suspects in crimes.  How about their use for authentication?  In the era of terrorism we are becoming more reliant on bio metric technologies to both identify people and prosecute them for crimes. What are the limits of this technology and how should we proceed?

Sidebar 2-10 Are There Unremarkable People?

Are there people for whom a biometric system simply does not work? That is, are there people, for example, whose features are so indistinguishable they will always pass as someone else?

Doddington et al. [DOD98] examined systems and users to find specific examples of people who tend to be falsely rejected unusually often, those against whose profiles other subjects tend to match unusually often, and those who tend to match unusually many profiles.

To these classes Yager and Dunstone [YAG10] added people who are likely to match and cause high rates of false positives and those people who are unlikely to match themselves or anyone else. The authors then studied different biometric analysis algorithms in relation to these difficult cases.

Yager and Dunstone cited a popular belief that 2 percent of the population have fingerprints that are inherently hard to match. After analyzing a large database of fingerprints (the US-VISIT collection of fingerprints from foreign visitors to the United States) they concluded that few, if any, people are intrinsically hard to match, and certainly not 2 percent.

They examined specific biometric technologies and found that some of the errors related to the technology, not to people. For example, they looked at a database of people iris recognition systems failed to match, but they found that many of those people were wearing glasses when they enrolled in the system; they speculate that the glasses made it more difficult for the system to extract the features of an individual’s iris pattern. In another case, they looked at a face recognition system. They found that people the system failed to match came from one particular ethnic group and speculated that the analysis algorithm had been tuned to distinctions of faces of another ethnic group. Thus, they concluded that matching errors are more likely the results of enrollment issues and algorithm weaknesses than of any inherent property of the people’s features.

Still, for the biometric systems they studied, they found that for a specific characteristic and analysis algorithm, some users’ characteristics perform better than other users’ characteristics. This research reinforces the need to implement such systems carefully so that inherent limitations of the algorithm, computation, or use do not disproportionately affect the outcome.

Sidebar 2-11 Fingerprint Examiners Make Mistakes

A study supported by the U.S. Federal Bureau of investigation [ULE11] addressed the validity of expert evaluation of fingerprints. Experimenters presented 169 professional examiners with pairs of fingerprints from a pool of 744 prints to determine whether the prints matched. This experiment was designed to measure the accuracy (degree to which two examiners would reach the same conclusion) and reliability (degree to which one examiner would reach the same conclusion twice). A total of 4,083 fingerprint pairs were examined.

Of the pairs examined, six were incorrectly marked as matches, for a false positive rate of 0.01 percent. Although humans are recognized as fallible, frustratingly we cannot predict when they will be so. Thus, in a real-life setting, these false positives could represent six noncriminals falsely found guilty. The false negative rate was significantly higher, 7.5 percent, perhaps reflecting conservatism on the part of the examiners: The examiners were more likely to be unconvinced of a true match than to be convinced of a nonmatch.

The issue of false positives in fingerprint matching gained prominence after a widely publicized error related to the bombings in 2004 of commuter trains in Madrid, Spain. Brandon Mayfield, a U.S. lawyer living in Oregon, was arrested because the FBI matched his fingerprint with a print found on a plastic bag containing detonator caps at the crime scene. In 2006 the FBI admitted it had incorrectly classified the fingerprints as “an absolutely incontrovertible match.”