Slashdot Mirror
Face-Scanning Loses by a Nose in Palm Beach
Rio writes: "A story from myCFnow.com reports that Palm Beach International Airport officials said
face-scanning technology will not become part of their airport's security system."
Looks like
the ACLU was right.
Checking a database of 15 employees, the technology gave false-negatives -- failed to recognize the test subjects -- over 50% of the time. A spokesperson said, "There's room for improvement." The Pentagon said
the same thing
in February. The false-positive rate is more important -- it isn't mentioned, but even if it were just 0.1%, Bruce Schneier argues,
it'd be useless.
Airport face identification isn't practical? Try telling the Australian Government that. They are trialling a hybrid face-recognition/biometric passport system that sends shivers up my spine.
"Einstein argued that [...] God is not capricious or arbitrary. No such faith comforts the software engineer." ~ Brooks
If it is a small sample then a high false negative rate is even worse.
If it can't identify 1 of 15, then what chance has it got of finding 1 person out of millions?
Bruce talks about 99.9%, so there's 0.1% left, not 0.01% as the story says right now.
No, sorry, just read Bruce's Cryptogram
Suppose this magically effective face-recognition software is 99.99 percent accurate. That is, if someone is a terrorist, there is a 99.99 percent chance that the software indicates "terrorist," and if someone is not a terrorist, there is a 99.99 percent chance that the software indicates "non-terrorist." Assume that one in ten million flyers, on average, is a terrorist. Is the software any good?
No. The software will generate 1000 false alarms for every one real terrorist. And every false alarm still means that all the security people go through all of their security procedures. Because the population of non-terrorists is so much larger than the number of terrorists, the test is useless. This result is counterintuitive and surprising, but it is correct. The false alarms in this kind of system render it mostly useless. It's "The Boy Who Cried Wolf" increased 1000-fold.
echo '[q]sa[ln0=aln80~Psnlbx]16isb572CCB9AE9DB03273snlbxq' |dc
Actually, over on plastic, we had a recent discussion about being on sex offender lists. The point was made that sex offender lists often include people who flashed someone 40 years ago and got caught. However, they're branded with the big 'A' (or is it 'P' these days?) wherever they go, in spite of the fact that these lists didn't exist back then. People think they're pedophiles when they might just have been sleeping with their underage girl/boy friend. Great.
So, with that in mind - is keeping blacklists (or greylists, really) of people a good idea at all? We like to pretend that they keep us 'safer' - but I bet the sixty-year-old gay man (prosecuted under one of those 'unenforced' state sodomy laws) who's driven out of his neighborhood with cries of 'think of the children!' isn't feeling any safer as a result of the existence of these lists.