discovery

A story of failed biometrics at a gym

business, security, tech in changing society / /

Fingerprints
Creative Commons License photo credit: kevindooley

From Jake Vinson’s “Cracking your Fingers” (The Daily WTF: 28 April 2009):

A few days later, Ross stood proudly in the reception area, hands on his hips. A high-tech fingerprint scanner sat at the reception area near the turnstile and register, as the same scanner would be used for each, though the register system wasn’t quite ready for rollout yet. Another scanner sat on the opposite side of the turnstile, for gym members to sign out. … The receptionist looked almost as pleased as Ross that morning as well, excited that this meant they were working toward a system that necessitated less manual member ID lookups.

…

After signing a few people up, the new system was going swimmingly. Some users declined to use the new system, instead walking to the far side of the counter to use the old touchscreen system. Then Johnny tried to leave after his workout.

… He scanned his finger on his way out, but the turnstile wouldn’t budge.

“Uh, just a second,” the receptionist furiously typed and clicked, while Johnny removed one of his earbuds out and stared. “I’ll just have to manually override it…” but it was useless. There was no manual override option. Somehow, it was never considered that the scanner would malfunction. After several seconds of searching and having Johnny try to scan his finger again, the receptionist instructed him just to jump over the turnstile.

It was later discovered that the system required a “sign in” and a “sign out,” and if a member was recognized as someone else when attempting to sign out, the system rejected the input, and the turnstile remained locked in position. This was not good.

The scene repeated itself several times that day. Worse, the fingerprint scanner at the exit was getting kind of disgusting. Dozens of sweaty fingerprints required the scanner to be cleaned hourly, and even after it was freshly cleaned, it sometimes still couldn’t read fingerprints right. The latticed patterns on the barbell grips would leave indented patterns temporarily on the members’ fingers, there could be small cuts or folds on fingertips just from carrying weights or scrapes on the concrete coming out of the pool, fingers were wrinkly after a long swim, or sometimes the system just misidentified the person for no apparent reason.

Fingerprint Scanning

In much the same way that it’s not a good idea to store passwords in plaintext, it’s not a good idea to store raw fingerprint data. Instead, it should be hashed, so that the same input will consistently give the same output, but said output can’t be used to determine what the input was. In biometry, there are many complex algorithms that can analyze a fingerprint via several points on the finger. This system was set up to record seven points.

After a few hours of rollout, though, it became clear that the real world doesn’t conform to how it should’ve worked in theory. There were simply too many variables, too many activities in the gym that could cause fingerprints to become altered. As such, the installers did what they thought was the reasonable thing to do – reduce the precision from seven points down to something substantially lower.

The updated system was in place for a few days, and it seemed to be working better; no more people being held up trying to leave.

Discovery

… [The monitor] showed Ray as coming in several times that week, often twice on the same day, just hours apart. For each day listed, Ray had only come the later of the two times.

Reducing the precision of the fingerprint scanning resulted in the system identifying two people as one person. Reviewing the log, they saw that some regulars weren’t showing up in the system, and many members had two or three people being identified by the scanner as them.

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Failure every 30 years produces better design

art, business, history, science / /

From The New York Times‘ “Form Follows Function. Now Go Out and Cut the Grass.“:

Failure, [Henry] Petroski shows, works. Or rather, engineers only learn from things that fail: bridges that collapse, software that crashes, spacecraft that explode. Everything that is designed fails, and everything that fails leads to better design. Next time at least that mistake won’t be made: Aleve won’t be packed in child-proof bottles so difficult to open that they stymie the arthritic patients seeking the pills inside; narrow suspension bridges won’t be built without “stay cables” like the ill-fated Tacoma Narrows Bridge, which was twisted to its destruction by strong winds in 1940.

Successes have fewer lessons to teach. This is one reason, Mr. Petroski points out, that there has been a major bridge disaster every 30 years. Gradually the techniques and knowledge of one generation become taken for granted; premises are no longer scrutinized. So they are re-applied in ambitious projects by creators who no longer recognize these hidden flaws and assumptions.

Mr. Petroski suggests that 30 years – an implicit marker of generational time – is the period between disasters in many specialized human enterprises, the period between, say, the beginning of manned space travel and the Challenger disaster, or the beginnings of nuclear energy and the 1979 accident at Three Mile Island. …

Mr. Petroski cites an epigram of Epictetus: “Everything has two handles – by one of which it ought to be carried and by the other not.”

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Thoughts on tagging/folksonomy

social software, tech in changing society, technology / /

From Ulises Ali Mejias’ “A del.icio.us study: Bookmark, Classify and Share: A mini-ethnography of social practices in a distributed classification community“:

This principle of distribution is at work in socio-technical systems that allow users to collaboratively organize a shared set of resources by assigning classifiers, or tags, to each item. The practice is coming to be known as free tagging, open tagging, ethnoclassification, folksonomy, or faceted hierarchy (henceforth referred to in this study as distributed classification) …

One important feature of systems such as these is that they do not impose a rigid taxonomy. Instead, they allow users to assign whatever classifiers they choose. Although this might sound counter-productive to the ultimate goal of organizing content, in practice it seems to work rather well, although it does present some drawbacks. For example, most people will probably classify pictures of cats by using the tag ‘cats.’ But what happens when some individuals use ‘cat’ or ‘feline’ or ‘meowmeow’ …

It seems that while most people might not be motivated to contribute to a pre-established system of classification that may not meet their needs, or to devise new and complex taxonomies of their own, they are quite happy to use distributed systems of classification that are quick and able to accommodate their personal (and ever changing) systems of classification. …

But distributed classification does not accrue benefits only to the individual. It is a very social endeavor in which the community as a whole can benefit. Jon Udell describes some of the individual and social possibilities of this method of classification:

These systems offer lots of ways to visualize and refine the tag space. It’s easy to know whether a tag you’ve used is unique or, conversely, popular. It’s easy to rename a tag across a set of items. It’s easy to perform queries that combine tags. Armed with such powerful tools, people can collectively enrich shared data. (Udell 2004) …

Set this [an imposed taxonomy] against the idea of allowing a user to add tags to any given document in the corpus. Like Del.icio.us, there needn’t be a pre-defined hierarchy or lexicon of terms to use; one can simply lean on the power of ethnoclassification to build that lexicon dynamically. As such, it will dynamically evolve as usages change and shift, even as needs change and shift. (Williams, 2004)

The primary benefit of free tagging is that we know the classification makes sense to users… For a content creator who is uploading information into such a system, being able to freely list subjects, instead of choosing from a pre-approved “pick list,” makes tagging content much easier. This, in turn, makes it more likely that users will take time to classify their contributions. (Merholz, 2004)

Folksonomies work best when a number of users all describe the same piece of information. For instance, on del.icio.us, many people have bookmarked wikipedia (http://del.icio.us/url/bca8b85b54a7e6c01a1bcfaf15be1df5), each with a different set of words to describe it. Among the various tags used, del.icio.us shows that reference, wiki, and encyclopedia are the most popular. (Wikipedia entry for folksonomy, retrieved December 15, 2004 from http://en.wikipedia.org/wiki/Folksonomy)

Of course, this approach is not without its potential problems:

With no one controlling the vocabulary, users develop multiple terms for identical concepts. For example, if you want to find all references to New York City on Del.icio.us, you’ll have to look through “nyc,” “newyork,” and “newyorkcity.” You may also encounter the inverse problem — users employing the same term for disparate concepts. (Merholz, 2004) …

But as Clay Shirky remarks, this solution might diminish some of the benefits that we can derive from folksonomies:

Synonym control is not as wonderful as is often supposed, because synonyms often aren’t. Even closely related terms like movies, films, flicks, and cinema cannot be trivially collapsed into a single word without loss of meaning, and of social context … (Shirky, 2004) …

The choice of tags [in the entire del.icio.us system] follows something resembling the Zipf or power law curve often seen in web-related traffic. Just six tags (python, delicious/del.icio.us, programming, hacks, tools, and web) account for 80% of all the tags chosen, and a long tail of 58 other tags make up the remaining 20%, with most occurring just once or twice … In the del.icio.us community, the rich get richer and the poor stay poor via http://del.icio.us/popular. Links noted by enough users within a short space of time get listed here, and many del.icio.us users use it to keep up with the zeitgeist. (Biddulph, 2004) …

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Dead for 3 years

commonplace book, true stories / /

From The Telegraph‘s “Skeleton woman’ dead in front of TV for years“:

A woman’s skeleton was discovered in her flat three years after she is believed to have died, it emerged today.

Joyce Vincent was surrounded by Christmas presents and the television and heating in her bedsit were still on.

The 40-year-old’s body was so decomposed that the only way to identify her was to compare dental records with a holiday photograph.

Police believe she probably died of natural causes in early 2003, and was only found in January this year when housing association officials broke into the bedsit in Wood Green, North East London.

They were hoping to recover the thousands of pounds of rent arrears that had piled up since her death.

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Four principles of modernity

commonplace book, science / /

From “Relativity, Uncertainty, Incompleteness and Undecidability“:

In this article four fundamental principles are presented: relativity, uncertainty, incompleteness and undecidability. They were studied by, respectively, Albert Einstein, Werner Heisenberg, Kurt Gödel and Alan Turing. …

Relativity says that there is no privileged, “objective” viewpoint for certain observations. … Now, if things move relative to each other, then obviously their positions at a given time are also measured relative to each other. …

Werner Heisenberg showed that if we built a machine to tell us with high precision were an electron is, this machine could not also tell us the speed of the electron. If we want to measure its speed without altering it we can use a different light but then we wouldn’t know where it is. At atomic scale, no instrument can tell us at the same time exactly where a particle is and exactly at what speed it is moving. …

If this system is complete, then anything that is true is provable. Similarly, anything false is provable false. Kurt Gödel got the intuition that traditional mathematical logic was not complete, and devoted several years to try to find one thing, a single thing that was inside the mathematics but outside the reach of logic. … Gödel’s incompleteness means that the classical mathematical logic deductive system, and actually any logical system consistent and expressive enough, is not complete, has “holes” full of expressions that are not logically true nor false. …

Turing’s halting problem is one of the problems that fall in to the category of undecidable problems. It says that it is not possible to write a program to decide if other program is correctly written, in the sense that it will never hang. This creates a limit to the verification of all programs, as all the attempts of building actual computers, usable in practice and different from Turing machines have been proved to be equivalent in power and limitations to the basic Turing machine.

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A 4000 year old ship in the desert

commonplace book, history / /

From “World’s oldest ship timbers found in Egyptian desert“:

The oldest remains of seafaring ships in the world have been found in caves at the edge of the Egyptian desert along with cargo boxes that suggest ancient Egyptians sailed nearly 1,000 miles on rough waters to get treasures from a place they called God’s Land, or Punt.

Florida State University anthropology professor Cheryl Ward has determined that wooden planks found in the manmade caves are about 4,000 years old – making them the world’s most ancient ship timbers. Shipworms that had tunneled into the planks indicated the ships had weathered a long voyage of a few months, likely to the fabled southern Red Sea trading center of Punt, a place referenced in hieroglyphics on empty cargo boxes found in the caves, Ward said.

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A cared-for mummy

commonplace book, weird / /

From “Mummified woman died naturally“:

A woman whose mummified body was dressed in a white gown and placed in front of a television for 2½ years died from heart disease. …

Officials never suspected abuse or foul play after finding Johannas Pope, 61, in her Madisonville home Jan. 4.

Pope told her caretaker, Kathy Painter, she didn’t want to be buried because she believed she would come back to life. …

Painter left Pope’s body in a chair in an air-conditioned room on the second floor of their Davies Place home.

Investigators learned that Painter took care of Pope’s body – trying to preserve it.

Owens said Painter put on gloves and removed the maggots from Pope’s body daily.

He said she used bug spray when they became too numerous to remove by hand. Investigators found 17 cans of bug spray in the house, he said. …

Painter even bought Pope new clothes just before officials discovered her body.

“She bought new clothes because she thought this was the time period she was coming back,” Owens said.

Family members kept a window air conditioner running to keep Pope’s body cool until about two months ago, when it broke, Owens said. Heating vents were covered during winter.

Some friends and relatives who visited were told Pope was upstairs, ill, Owens said. …

There is no Ohio law mandating the reporting of a dead body.

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New communication, new art forms

on writing, social software, tech in changing society / /

From Jim Hanas’ “The Story Doesn’t Care: An Interview with Sean Stewart“:

I think that every means of communication carries within itself the potential for a form of art. Once the printing press was built, novels were going to happen. It took the novel a little while to figure out exactly what it was going to be, but once the press was there, something was going to occur. Once motion picture cameras were around, the movies—in some format or another—were going to happen.

I modestly or immodestly think that [developers of alternate reality games] got some things fundamentally right about the way the web and the internet want to tell stories in a way that not everyone had gotten quite when we lucked into it. What people do on the web is they look for things and they gossip. We found a way of storytelling that has a lot to do with looking for things and gossiping about them. …

Suspension of disbelief is a much more fragile creation in the kinds of campaigns we’re doing right now than it is in novels, where everyone has taken the last two hundred years to agree on a set of rules about how you understand what’s happening in a book. That hasn’t happened here. Right now, this is at an unbelievably fluid and dynamic stage—a whole bunch of things that have been figured out in other art forms, we’re working them out on the fly.

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The inevitability of taxation

business, overheard, politics, science / /

From Giampaolo Garzarelli’s Open Source Software and the Economics of Organization:

Whenever organizational forms present rapid change because of their strong ties to technology, public policy issues are always thornier than usual. Indeed, historically, it seems that every time that there’s the development of a new technology or production process, the government has to intervene in some fashion to regulate it or to extract rents from it. This point is well- encapsulated in the well-known catch-phrase attributed to Faraday. After Faraday was asked by a politician the purpose of his recently discovered principle of magnetic induction in 1831, he replied: “Sir, I do not know what it is good for. However, of one thing I am quite certain, some day you will tax it”.

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Dead for a while

commonplace book, weird / /

From BBC News:

A man lay dead in his flat for 15 months before his body was found.

Recording an open verdict into the death of Derek Perkins, 63, coroner Dr Nigel Chapman said he had never known a body to be undiscovered for so long.

The exact date of Mr Perkins’ death is unknown, but a newspaper found near his body was dated 31 December, 2002. …

In a written statement, Nottingham City Council said they had tried to make contact during the past six months by letter, phone and visits.

It said faster rent arrears procedures should help the council investigate problems sooner.

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