Speaker 1: Welcome to tech Stuff, a production from I Heart Radio.
Speaker 1: Hey there, and welcome to tech Stuff. I'm your host,
Speaker 1: Jonathan Strickland. I'm an executive producer with iHeart Radio and
Speaker 1: a love of all things tech. It is time for
Speaker 1: a classic episode. This episode originally aired on April two, fourteen.
Speaker 1: It is called Biometrics Digital Fingerprinting Enjoy. We thought, hey,
Speaker 1: we should talk about biometrics, and then we started looking
Speaker 1: into it and getting really excited, and then we realized, hey,
Speaker 1: there's a lot to talk about, right. You know. Biometrics,
Speaker 1: of course, being the measurable biological or behavioral characteristics used
Speaker 1: for for any given individual. Yes, this is what how
Speaker 1: the FBI says, this is what the biometrics are. So, uh,
Speaker 1: you know, it's one of those things where we knew
Speaker 1: it was a huge time bick and we decided to
Speaker 1: narrow it down. So today we're specifically focusing on your fingerprints. Well,
Speaker 1: not your fingerprints, I mean, I mean everyone's fingerprints. No,
Speaker 1: see the person sitting next to you, No, not that one,
Speaker 1: the other one, that person's fingerprints. That's that's the one
Speaker 1: we're concentrating on. So yeah, because everyone has has different fingerprints,
Speaker 1: I mean like everyone, right, and this is something that
Speaker 1: has been known for a while but then forgotten and
Speaker 1: then rediscovered. So we're going to talk about that because
Speaker 1: it's kind of funny. So these days we think of
Speaker 1: biometrics as sort of those automated ways to verify your
Speaker 1: identity based on some sort of biological characteristic, like you know,
Speaker 1: the eye scan or the fingerprints scan or whatever. Vocal
Speaker 1: scans as well, you know, like the voice imprint. Lots
Speaker 1: of different Hollywood versions of this. But you know, again,
Speaker 1: going into that fingerprint approach, we thought that, uh, you know,
Speaker 1: we we look at not just how we've defined it
Speaker 1: and how stuff works, but look at a whole history
Speaker 1: of fingerprinting. We're not the first podcast to do this,
Speaker 1: by the way, certainly not. Josh and Chuck of Stuff
Speaker 1: you Should Know did an episode on April called how
Speaker 1: Fingerprinting Works, and they go pretty deeply into the history
Speaker 1: and say many pithy things. So if you would like
Speaker 1: to check that episode out, you can go to Stuff
Speaker 1: you Should Know dot com right and just stick around,
Speaker 1: because we're gonna say some pithy things too. We are
Speaker 1: going to cover some of the history kind of a
Speaker 1: quick overview, but first I thought I would read a
Speaker 1: couple of little excerpts from our article on how fingerprints
Speaker 1: scanners work, because there are a couple that I thought
Speaker 1: were really interesting from how stuff works dot Com. Neither
Speaker 1: of us actually wrote this. Nope, Nope, I didn't write
Speaker 1: this one. This one says people have tiny ridges of
Speaker 1: skin on their fingers because this particular adaptation was extremely
Speaker 1: advantageous to the ancestors of the human species. The pattern
Speaker 1: of ridges and valleys on fingers make it easier for
Speaker 1: the hands to grip things in the same way a
Speaker 1: rubber tread pattern helps to attire grip the road. The
Speaker 1: other function of fingerprints is a total coincidence. Like everything
Speaker 1: in the human body, these ridges form through a combination
Speaker 1: of genetic and environmental factors. The genetic code and DNA
Speaker 1: gives general orders in the way skin should form in
Speaker 1: the developing fetus, but the specific way it forms is
Speaker 1: a result of random events. The exact position of the
Speaker 1: fetus in the womb at a particular moment, and the
Speaker 1: exact composition and density of surrounding amniotic fluid decides how
Speaker 1: every individual ridge will form. This, by the way, is
Speaker 1: how identical twins can have different fingerprints pretty cool because
Speaker 1: you know, genetically they're identical, but their fingerprints are different,
Speaker 1: still different. Interesting. So looking at this history, you might think, Okay,
Speaker 1: I've heard about fingerprinting, particularly when it applies to law enforcement.
Speaker 1: That's probably where a lot of people are familiar with it,
Speaker 1: besides the verification. Sure, sure, and uh and a couple
Speaker 1: popular media pieces have talked recently about Um. I mean
Speaker 1: you you get things like Ripper Street or Sleepy Hollow
Speaker 1: having characters going like this new fingerprinting thing in the amaging,
Speaker 1: amazing Age of Victoria. Um, not not so much. Actually,
Speaker 1: so fingerprints people, Well, first of all, people have been
Speaker 1: aware of them for ages because we're curious folks, you know,
Speaker 1: human beings. We we were very curious and narcissistic. We
Speaker 1: like to learn stuff and we like to look at ourselves.
Speaker 1: And how do I know that this dates back are
Speaker 1: ages and ages and ages ago because we have prehistoric
Speaker 1: depictions found in Nova Scotia and it depicted a hand
Speaker 1: with ridge patterns on the skin. Now, that does not
Speaker 1: mean that the ancient Nova Scotians were familiar with the
Speaker 1: fact that all the fingerprints were unique, and therefore no
Speaker 1: to individuals had the same ones, but at least showed
Speaker 1: that you know, yeah, they noticed them. Yeah, but the
Speaker 1: ancient Babylonians may have actually used fingerprints to differentiate people. Um,
Speaker 1: we've found fingerprints in clay to to sign business transactions,
Speaker 1: and the ancient Chinese used inked fingerprints for both business
Speaker 1: purposes and child identification. And in the thirteen hundreds in Persia,
Speaker 1: official government documents often included fingerprints, probably to indicate they
Speaker 1: were authorized and official. Now, according to the US Marshall's Office,
Speaker 1: which has an entire web page devoted to fingerprinting in
Speaker 1: the history of it, one government official in Persia at
Speaker 1: that time made the observation that no two fingerprints were alike,
Speaker 1: which obviously would be very important if you're making a
Speaker 1: document official or authorized. But it wasn't until the eighteen
Speaker 1: eighties that that amazing Age of Victoria previously mentioned that
Speaker 1: we got some kind of official classification system, right. It
Speaker 1: wasn't until the modern era that we started seeing it.
Speaker 1: In uh story, it wasn't even in wide use at
Speaker 1: the beginning. It was just kind of exploratory. Dr Henry
Speaker 1: Faulds back in eighteen eighty proposed using fingerprints for identification
Speaker 1: as well as a means of classifying them. So he
Speaker 1: forwarded these ideas to a certain Charles Darwin, very important
Speaker 1: historical figure in his own right. But Darwin at the
Speaker 1: time was towards the end of his life and felt
Speaker 1: that he did not have the necessary UH time and
Speaker 1: energy to devote to this thought. It was really interesting, however,
Speaker 1: so he forwarded the information along to a cousin of
Speaker 1: his named Francis Galton. So false would write a scientific
Speaker 1: paper about his methods and actually identified a fingerprint, ascertain
Speaker 1: the identity of the person who left that fingerprint on
Speaker 1: bottle of alcohol. Shouldn't come as any surprise. I guess
Speaker 1: this brings us all together. It does. Then in three
Speaker 1: Mark Twain would would use this this new startling scientific
Speaker 1: information in a story. Yeah, it was in Life on
Speaker 1: the Mississippi, And in that one of the elements of
Speaker 1: that story is a murderer is identified through the use
Speaker 1: of fingerprints. And he would revisit the idea in a
Speaker 1: book called Putting Head Wilson Putting Head. Well, so it's interesting. Now,
Speaker 1: this was before anyone was actually using UH fingerprints in
Speaker 1: any kind of criminal investigations on an official basis. It
Speaker 1: had not been science fiction, really was. It kind of
Speaker 1: was so so that was exciting. But but soon in
Speaker 1: eighteen eighty eight, Sir Francis Galton, remember the cousin to
Speaker 1: Charles Darwin, who had received information about this about ten
Speaker 1: years previous, um, began his own study of fingerprints. Yep.
Speaker 1: He wrote a book in eighteen ninety two and put
Speaker 1: forth a formal classification system and identify the tiny characteristics
Speaker 1: used to differentiate fingerprints, which now we call Galton's details.
Speaker 1: He also observed that fingerprints don't change over the lifetime
Speaker 1: of a person, so the ones you have when you're
Speaker 1: a kid are the same ones you have when you're old.
Speaker 1: Originally wanted to kind of link fingerprints to certain types
Speaker 1: of traits like intelligence or heredity, which is so racist. Yeah,
Speaker 1: kind of essentially, I think this was almost in an
Speaker 1: attempt And I don't know enough about Galton to say
Speaker 1: this for sure, but it seems like an attempt to
Speaker 1: justify certain societies beliefs in certain people, that kind of thing. Yeah,
Speaker 1: it wasn't necessarily so racist, but um, but it kind
Speaker 1: of runs in that direction. Yeah, Because I mean, the
Speaker 1: idea that you could identify a person's intelligence based on
Speaker 1: their fingerprints already seems a little sketchy, and in fact,
Speaker 1: he did determined that there was no connection. There was
Speaker 1: no there were no identifier marks in a person's fingerprints
Speaker 1: that would give you any clue as to that person's
Speaker 1: intelligence or genetic background. However, he did figure out that
Speaker 1: there were a lot of differences and that people didn't
Speaker 1: weren't likely to have the same fingerprints. Yeah, unlikely, in
Speaker 1: the order of one in sixty four billion, that's pretty unlikely.
Speaker 1: So in eight we get the first use of fingerprints
Speaker 1: in a criminal investigation on an official level. Uh one vs.
Speaker 1: Tech and I I'm sure I butchered his last name.
Speaker 1: Who was a police officer in Argentina used them in
Speaker 1: a murder investigation. It was actually a really tragic case,
Speaker 1: but the discovery meant that he was able to solve
Speaker 1: this mystery and prove that the person that was believed
Speaker 1: to have been the murderer was in fact not the killer. So, uh,
Speaker 1: not only was it the first use, but it was
Speaker 1: a pretty dramatic example of it. Now, between we're gonna
Speaker 1: skip to nineteen eighteen, but between the late nineteenth century
Speaker 1: and the early twentieth century he started to see fingerprints
Speaker 1: get adopted into various legal organizations all around the world.
Speaker 1: The United Kingdom and the United States were leading the way,
Speaker 1: but it was all over the place. So by nineteen
Speaker 1: eighteen you have Edmund Lekard who says that you only
Speaker 1: need twelve points of similarity between an individual's fingerprint and
Speaker 1: a target fingerprint to serve as a positive identification. Now
Speaker 1: you may have heard about those twelve points of singularity,
Speaker 1: that this is somehow like a legal thing, that if
Speaker 1: you were able to meet those twelve points of singularity,
Speaker 1: you have the legal basis to say this person did this.
Speaker 1: Uh not necessarily a legal definition at all. In fact,
Speaker 1: UH countries have very very different ways of saying whether
Speaker 1: or not a fingerprint is a valid match for another one,
Speaker 1: and some, like the United States, do not have a
Speaker 1: minimum number of resemblances that need to be there in
Speaker 1: order for you to call it a match. Now, usually
Speaker 1: law enforcement agencies rely on experts who give their expert
Speaker 1: opinion and therefore putting their own reputation on the line
Speaker 1: as to whether or not something matches. And of course,
Speaker 1: now these days we rely very heavily on digital information,
Speaker 1: which with very very complex and intelligent algorithms that will
Speaker 1: that will do some really interesting like work. Yeah, and
Speaker 1: so with that, you know, the the level of a
Speaker 1: confidence grows quite a bit. So, uh, just so you
Speaker 1: know that twelve points of similarity not necessarily a legal standard.
Speaker 1: Nineteen four that's when Congress enabled had an act that
Speaker 1: established the new division for the Federal Bureau of Investigation
Speaker 1: also known as the FBI. Uh And this division was
Speaker 1: called the Identification Division. I bet you can guess what
Speaker 1: it did. So it became kind of a centralized fingerprint
Speaker 1: file for the entire country. So not it wasn't necessarily
Speaker 1: uh standard procedure for every law enforcement agency out there
Speaker 1: to send a copy to the FBI, But that's kind
Speaker 1: of what started to happen, so that, uh, there could
Speaker 1: be this sort of cooperation between different departments which often
Speaker 1: wouldn't have any communication with each other. Sure sure, by
Speaker 1: nineteen forty six, the FBI would have processed more than
Speaker 1: a hundred million fingerprint cards. Yeah, not just processed, but
Speaker 1: they did that by hand, right right, and it would
Speaker 1: be two million by one, So two million physical cards
Speaker 1: with fingerprints on them. I mean, just imagine how many, like,
Speaker 1: how how much storage you need just for me, it's two.
Speaker 1: I can't even I can't even imagine it. But by
Speaker 1: the FBI introduced the Integrated Automated Fingerprint Identification System or
Speaker 1: if SO. It's the largest fingerprint database in the world
Speaker 1: and its computer automated. It takes about twenty seven minutes
Speaker 1: for the system to comb through every single file in
Speaker 1: its database to find out if there is a potential match.
Speaker 1: During a criminal investigation, it's different. If it's a civil case,
Speaker 1: it's actually like more than an hour. But for criminal investigation,
Speaker 1: for all the criminal files that are storing this database,
Speaker 1: twenty seven minutes from the time you actually input the
Speaker 1: suspects fingerprint. I imagine that's a lot faster than whatever
Speaker 1: in turn they sent down to the basement. Well yeah,
Speaker 1: because I mean you would have to narrow down the
Speaker 1: person quite a bit before you could ever start comparing. Right,
Speaker 1: this is a man, so cut out all the women
Speaker 1: and then go like there are seventy million of them
Speaker 1: down there. Uh yeah, that would be that would be
Speaker 1: a daunting task. So in the digital age, we can
Speaker 1: actually analyze this stuff way better than we ever could,
Speaker 1: Like you don't have to use the naked eye anymore
Speaker 1: and try and find those little ridges and stuff. You
Speaker 1: can actually rely very heavily upon computer systems, and once
Speaker 1: we started getting those computer systems in place, they pretty
Speaker 1: soon thereafter became um commercially available. Yeah. Yeah, we had
Speaker 1: some fingerprint verification systems that have been around for a
Speaker 1: few decades now. On the consumer level, they've only been
Speaker 1: available fairly recently. And you might be thinking, oh, yeah, yeah,
Speaker 1: the iPhone five s because it has that that fingerprint
Speaker 1: scanner where you can use that to log into your phone.
Speaker 1: That's the first smartphone to ever use that, right, Nope, no, no,
Speaker 1: there's actually a mobile device. The first mobile device that
Speaker 1: I found was a one that dated from two thousand three,
Speaker 1: the H and Boy. The name of this is phenomenal.
Speaker 1: HP names their products in such catchy ways. It's the
Speaker 1: HP I pack, I p a Q P PC pocket PC.
Speaker 1: Oh yeah, it just rolls off the tongue. Yeah, it
Speaker 1: really is. I mean, with a name like that, how
Speaker 1: could you resist I phone my phone? So at any rate,
Speaker 1: this was the first mobile device to incorporate finger scanning technology,
Speaker 1: but it was also sort of the edge of a
Speaker 1: boom for the technology. UM it was being extended for
Speaker 1: for wide consumer use. At the time. I mean, you know,
Speaker 1: keyboards and mice had them, laptops had them. You could
Speaker 1: buy a USB scanner for multipurpose use and encrypt everything
Speaker 1: with your fingerprint, right, you could end up creating, for example,
Speaker 1: with a copier. You could end up telling people, all right,
Speaker 1: this group of folks are authorized to make copies. Anyone
Speaker 1: who's not on this list cannot make copies. And you
Speaker 1: would walk up to make copies. And if you weren't
Speaker 1: on that list, then I guess no fun Christmas party
Speaker 1: Shenanigans for you. But but but also opening this up
Speaker 1: to the consumer market meant that a lot of people
Speaker 1: started finding the flaws in the technology. Oh yes. In
Speaker 1: December five, clarks And University researchers announced that they could
Speaker 1: fool of the world's fingerprint scanners using an incredibly sophisticated,
Speaker 1: expensive substance. Yeah, they could just go out to toy
Speaker 1: store and buy some Plato and essentially make a copy
Speaker 1: of a fingerprint and put it on any optical scanner.
Speaker 1: And we'll talk about the optical scanners in a little bit.
Speaker 1: And it worked really well. So that gave people some
Speaker 1: pause and thought, maybe we should come up with something
Speaker 1: besides optical scanners too, because fingerprint identification is a great idea,
Speaker 1: but if it's if it's that easy to fool, we
Speaker 1: have to find a different way of measuring it. So
Speaker 1: then there was a totally different expose on September one,
Speaker 1: two thousand and six, when our beloved MythBusters decided to
Speaker 1: do a fingerprint scanner scam of their own. They decided
Speaker 1: to see if they could fool one, and this one
Speaker 1: was a little different. It wasn't just an optical scanner.
Speaker 1: It was supposed to also detect sweat from pores in
Speaker 1: the fingertips. Okay, so so you can't just use a
Speaker 1: lump of plato or good photograph. You have to have
Speaker 1: something that sweats has to have to otherwise it's never
Speaker 1: gonna work. So what did they do. They made a
Speaker 1: latext copy of a fingerprint and then they did a
Speaker 1: very sophisticated thing in order to simulate sweat. Yeah, and
Speaker 1: it worked. So if you can't play dough it, lick it,
Speaker 1: I guess is the moral of that story. I think
Speaker 1: I think that that's really what we all should learn
Speaker 1: from this today. Probably so anyway, they're still seeing this
Speaker 1: kind of technology being rolled out. But it's not just
Speaker 1: an optical scanners, and even optical scanners have gotten a
Speaker 1: lot better than they were back in two thousand five.
Speaker 1: We'll be right back with more digital fingerprinting after these
Speaker 1: short messages. All right, I had just talked about optical scanners,
Speaker 1: and those are one of the ones that are the
Speaker 1: easiest to explain and uh and fairly common even today.
Speaker 1: In fact, not my work computer, but my home computer
Speaker 1: has my home laptop has a little optical scanner. So
Speaker 1: if I want to log in, I can just swipe
Speaker 1: my finger across it. So optical scanners use something that
Speaker 1: is found in digital cameras and camcorders called a charge
Speaker 1: coupled device or c c D. Now, essentially that's a
Speaker 1: light sensor. It's got an array of things called photo sites.
Speaker 1: Now that's light sensitive diodes, and it's works pretty much
Speaker 1: the way you would imagine. So photons, those little particles
Speaker 1: of light when they make a collision with these photo sites,
Speaker 1: it generates a little electrical signal and those can then
Speaker 1: be compiled and converted into a digital image. And it's
Speaker 1: essentially the same process that digital cameras used to take pictures.
Speaker 1: And here's the thing though, So if I put my
Speaker 1: finger on an optical scanner, I'm actually blocking light. And
Speaker 1: unless you happen to be e T the extraterrestrial, your
Speaker 1: finger probably isn't emitting light. So how the heck is
Speaker 1: it getting this picture? Well, it uses a flash, yeah,
Speaker 1: except in this case of flash is probably like a
Speaker 1: single l ED or for some scanners maybe an array
Speaker 1: of LEDs light emitting diodes in other words, and so
Speaker 1: that provides the light that is necessary to take this image.
Speaker 1: And uh, then the c c D creates an image
Speaker 1: of your fingertip. However, it's a little funky. It's inverted, right.
Speaker 1: The dark areas are going to represent the ridges that
Speaker 1: the raised portions of your fingertip, and the light areas
Speaker 1: are going to represent the values. Yeah, so it's kind
Speaker 1: of like looking at a negative, a photo negative. Uh.
Speaker 1: And it makes sense because stuff that's reflecting more light
Speaker 1: is going to create a lot a bigger electrical signal,
Speaker 1: thus creating that you know, the charge couple device is
Speaker 1: going to make that into a darker portion the valleys.
Speaker 1: The light is not as much of it's going to
Speaker 1: reflect back, so you get a weaker electrical signal. That's
Speaker 1: why it gets lighter. Uh So, if you were to
Speaker 1: scan your finger and UM and it tells you that
Speaker 1: it's a good scan, because most of these devices also
Speaker 1: have some sort of fail safe in them that will
Speaker 1: alert you if there wasn't enough enough differentiation between the
Speaker 1: dark and light parts. Right, that the same way that
Speaker 1: you're that your camera UM sometimes will take a picture
Speaker 1: that's that's overdeveloped or underdeveloped. The same thing can happen here. Yeah,
Speaker 1: So if you wanted to, like if you most of
Speaker 1: the software has let error function built into it, so
Speaker 1: it can tell and it will ask you to scan again, right,
Speaker 1: So then you would scan again. So if it's the
Speaker 1: first time you're using it, then you would also end
Speaker 1: up creating a profile in some way. It might not
Speaker 1: be you, it might be an administrator, but something that
Speaker 1: links the fingerprint to who you are and what access
Speaker 1: you are supposed to have will have then on subsequent uses,
Speaker 1: what will happen is that when you scan your finger
Speaker 1: it will go through its database of of identities that
Speaker 1: have fingerprints attached to them look for you. If you're there,
Speaker 1: then it will authorize you for whatever use you're allowed. So,
Speaker 1: for instance, on my home computer, I've given myself very
Speaker 1: strict restrictions because I am not to be trusted. Uh,
Speaker 1: and so all I'm able to do is play a
Speaker 1: pirated copy of Flappy Bird. That's not true, I don't
Speaker 1: have Flappy Bird. But at any rate, you know, that's
Speaker 1: the basic You know, that's the basic procedure, right, And
Speaker 1: and so if your fingerprint is not found in that database,
Speaker 1: you get an error. So either you have to swipe
Speaker 1: it again or or scan it again if it's not swipe.
Speaker 1: All depends on what kind of scanner you're at, or
Speaker 1: you end up saying, uh, the jig is up, you
Speaker 1: got me, I don't really belong here, and then you
Speaker 1: run away. Um. So that that's the basic thing. And
Speaker 1: what they're looking for. It's not the entire pattern of
Speaker 1: your fingertip. It's looking for for a specific minutia about it,
Speaker 1: certain types of patterns and it. And it depends on
Speaker 1: the software that the scanner is using. Um. It might
Speaker 1: be the places where the ridges converge, um or split
Speaker 1: apart at the end, or um any any other kind
Speaker 1: of detail. It's going to be unique to you. Right.
Speaker 1: So in other words, all has to do is say, hey,
Speaker 1: there are these three points on this fingertip, uh that
Speaker 1: are unique that that's all I'm concerned about. And if
Speaker 1: the fingerprint that scan has those three points, I know
Speaker 1: it's this person and they can be let through by
Speaker 1: constraining on the minutia, then you really cut down on
Speaker 1: all the rest of the data that's necessary to have
Speaker 1: a verification. Right, you can kind of throw everything else
Speaker 1: out and concentrate on that and right. Uh and and
Speaker 1: they're pretty good, like we said, though they can sometimes
Speaker 1: be fooled by a really high quality picture of a fingerprint. Right,
Speaker 1: So what if you instead of looking at a picture,
Speaker 1: you were to make sure the fingerprint in some other way,
Speaker 1: such as capacitance right, Because capacitense touch screens are totally
Speaker 1: a thing. Yeah, So it's very similar to what a
Speaker 1: regular capacityans touch screen is. So you know, there are
Speaker 1: different ways of doing touch screens as well. There's somewhere
Speaker 1: you have to use pressure. With the benefit of that
Speaker 1: is you could be wearing gloves and still work a
Speaker 1: pressure version. The downside is that when people are expected
Speaker 1: to apply pressure to delicate material, they sometimes destroy it completely, right,
Speaker 1: or it'll at least decrease the lifespan of that object
Speaker 1: by quite a bit. Capacitance, however, uses weak electric fields.
Speaker 1: So when you make contact with a screen, a touch screen,
Speaker 1: that's using capacitance. See, you're a conductor. I don't mean
Speaker 1: that you conduct trains, Nor do I mean that you
Speaker 1: Maybe you do, Maybe you do, Maybe you do. Maybe
Speaker 1: you conduct orchestras. Maybe you conduct orchestras on a train.
Speaker 1: I don't know. But what I'm talking about, you do
Speaker 1: call us because that sounds fascinating, kind of cool. Actually,
Speaker 1: But now I'm talking about electrical conductivity. So we can
Speaker 1: conduct electricity. It's not great for us to have a
Speaker 1: lot of it, but tiny amounts don't hurt us. Sure,
Speaker 1: And as it turns out, the ridges and valleys on
Speaker 1: your fingers conduct slightly different amounts of electricity. This blows
Speaker 1: my mind. I mean to think that the raised parts
Speaker 1: of your fingerprint and the valleys of your fingerprint are
Speaker 1: distinct enough to create a measurable difference in capacitance. You know,
Speaker 1: it's something I never would have imagined. And it's really
Speaker 1: a sensor issue here. I mean the fact that we
Speaker 1: can create these these cells, these capacitor plate cells that
Speaker 1: are sensitive enough to tell that yeah. Technology, so what's
Speaker 1: happening is when you put your finger down on one
Speaker 1: of these capacity scanners, you are actually you're you're acting
Speaker 1: as a capacitance plate, right Your fingertip is acting is one,
Speaker 1: and you already have other ones inside the scanner itself,
Speaker 1: and it will end up creating voltages, and there will
Speaker 1: be different differences in those voltages. The differences between the
Speaker 1: ridges and the valleys based on how far away they
Speaker 1: are from the from the cells. Yeah, so if it's
Speaker 1: a valley, it's going to be lower capacitance because the
Speaker 1: distance is greater. Capacitance is very dependent upon distance. So
Speaker 1: if you move to capacitance plates far enough apart, they
Speaker 1: will not be they will not work together. We've got
Speaker 1: a little bit more to say about biometrics, but first
Speaker 1: let's take a quick break. It's amazing that the valleys,
Speaker 1: just by being that much further away will create a
Speaker 1: different voltage than the ridges. And then having a whole,
Speaker 1: a whole set of these cells set up next to
Speaker 1: one another, um it allows the scanner to to sort
Speaker 1: of make a digital picture of your fingerprint, but just
Speaker 1: using electricity rather than light. The data from each one
Speaker 1: is again compiled and then converted into an image of sorts. Yeah. Yeah,
Speaker 1: you can think of it as like an image made
Speaker 1: with electricity. And this is the sort of scanner that
Speaker 1: the iPhone five S uses, so it's not an optical scanner.
Speaker 1: One of the big benefits of this technology is that
Speaker 1: it's easier to make it really compact and manatorized, which
Speaker 1: is why you could find it in things like handheld electronics.
Speaker 1: Right sure. Um. However, this technology can also be fooled
Speaker 1: um sometimes by by mold of a finger um or
Speaker 1: if someone has gone and calibrated the scanner to look
Speaker 1: for things like like heat or a pulse. Um. You
Speaker 1: can you can use one of those movie tricks, like
Speaker 1: a gelatin or silicone mold of a finger um pasted
Speaker 1: onto a different, different finger. Yeah. My favorite version of
Speaker 1: getting past a capacitance or an optical scanner is to
Speaker 1: use the finger that's been removed from the person who
Speaker 1: had the authorization. Yeah, yeah, snipping, that's that's that's your favorite.
Speaker 1: That's my favorite out in the field. That's what you like.
Speaker 1: We had this discussion about the born identity before we
Speaker 1: came into the podcast. This is totally true. Uh, I
Speaker 1: don't like to discuss my actual field operative kind of
Speaker 1: mentality and strategies. But yes, I do love doing that.
Speaker 1: So thermal scanners, well, this one's a little different because
Speaker 1: it's a it's a heat scanner, and again it's one
Speaker 1: of those ideas where it measures the differences in heat
Speaker 1: between ridges and valleys. Once again, you're going to get
Speaker 1: a slightly higher temperature from the ridges than you do
Speaker 1: with the valleys. The valleys that are essentially pockets of air.
Speaker 1: There's some downside with this one. One of the problems
Speaker 1: with thermal scanners is that if you if it takes
Speaker 1: too long to do the scan, the temperature differences are
Speaker 1: going to equalize across the and I wind up get
Speaker 1: you just get a blank fingerprint, like a big blank fingerprint.
Speaker 1: Not useful. This next one is super cool. It's ultrasonic
Speaker 1: ultrasonic sensors, so right, yeah, Well, we did a whole
Speaker 1: episode about ultrasound called How Ultrasound Works. Crazily enough that
Speaker 1: published jan if you would like to hear all about
Speaker 1: how this technology works. But um, but it's essentially echolocation. Yeah,
Speaker 1: you're sending out sound signals and then you're waiting for
Speaker 1: them to bounce back and by measuring the amount of
Speaker 1: time it took to go out and come back. You
Speaker 1: get an idea of how far away something is. Well.
Speaker 1: That works, you know, in lots of different ways, including
Speaker 1: being able to tell a fingerprint, being able to read
Speaker 1: a fingerprint. It can go even deeper than that, exactly,
Speaker 1: it can go into tissues. So if you wanted, you
Speaker 1: could create an ultrasonic fingerprint scanner that scan not just
Speaker 1: the fingerprint itself, but the underlying veins that are in
Speaker 1: your finger which also are going to be unique to you.
Speaker 1: So that's a lot harder to fake than a fingerprint.
Speaker 1: Like you're not going to get a really high resolution
Speaker 1: image of veins and then create a fake finger easily.
Speaker 1: It would be really difficult. I mean, but you could
Speaker 1: use your favorite application, which is removing someone's finger and
Speaker 1: say that right unless you had also built into the
Speaker 1: software to detect living tissue, because to see if blood
Speaker 1: is moving through the veins the vessels. If it's not
Speaker 1: detecting blood, it's good to say, y'all, this is messed up.
Speaker 1: You need to send someone down right now the fingerprint scanner.
Speaker 1: Things that are bad are happening. That's exactly what the
Speaker 1: voice that uses too, I I assumed run into it
Speaker 1: in the field all the time. So yeah, I mean
Speaker 1: this is uh, you know, that's we're making light of
Speaker 1: it because to be serious about it is so squeaky, terrifying.
Speaker 1: But at any rate, it does mean that you can
Speaker 1: build those sort of parameters, and so it's not just
Speaker 1: looking at the fingerprint and the veins underneath, but also
Speaker 1: to make sure it is truly a valid uh entry,
Speaker 1: so that they don't you know, you don't end up
Speaker 1: compromising security. Um. And there there's also I wanted to
Speaker 1: mention very briefly the difference between those static uh fingerprint scanners,
Speaker 1: especially the optical ones where you just hold your finger
Speaker 1: down and you wait for it. It's kind of like
Speaker 1: a copier, right right, and the swipe style that you
Speaker 1: were talking about having on your home laptop exactly. So
Speaker 1: if you've ever had a laptop or any other device
Speaker 1: that has like a narrow window and you're supposed to
Speaker 1: swipe your finger across that window, the reason for that
Speaker 1: is that it's actually taking a series of quote unquote
Speaker 1: images of your finger. However the implementation is actually being used,
Speaker 1: it's it's doing then a quick series. Machines are really fast,
Speaker 1: so they can do this without any real problem. They're
Speaker 1: looking for those minutia that we talked about before, and
Speaker 1: they're able to uh to use software to compile them.
Speaker 1: But you know, it's it's nifty having the smaller form
Speaker 1: factor because, like we said, uh, then you can miniaturize,
Speaker 1: you can put them in something like a cell phone
Speaker 1: and also make them cheaper. Exactly. Yeah, you've got this
Speaker 1: little window and your finger moves past the window instead
Speaker 1: of the window having to be big enough to So
Speaker 1: it's it's really uh an interesting development and uh pretty cool. Also,
Speaker 1: we can mention that biometric systems, many of them, not
Speaker 1: necessarily all of them, but many of them end up
Speaker 1: translating your fingerprint in to an algorithm that or an
Speaker 1: algorithm rather does the translating that turns into a bunch
Speaker 1: of ones and zeros, all right, right. A digitization um
Speaker 1: sometimes called a hash. It's like a personal code, like
Speaker 1: a really long pin. Yeah. So in this case, what
Speaker 1: you would say is that it's not storing an image
Speaker 1: of your fingerprint. It's not like if you were to
Speaker 1: somehow hack into the computer you would suddenly see a
Speaker 1: on your screen a representation of your fingerprint. It would
Speaker 1: just mean that it would take the the pattern of
Speaker 1: ridges and valleys and all the night nutia convert that
Speaker 1: into this this hash, this this long string of ones
Speaker 1: and zeros, and the next time you scan it, if
Speaker 1: the if the same hash comes up, then it is
Speaker 1: a match and it says, all right, identification has been verified.
Speaker 1: But it's not actually like an actual real image of
Speaker 1: your fingerprint. And the reason why a lot of these
Speaker 1: companies try to talk about you know this as as
Speaker 1: a big selling point is that it doesn't allow you
Speaker 1: to recreate a person's fingerprint if you were to get
Speaker 1: hold of those hash So it's not like you would say, oh,
Speaker 1: if I just put this through an image program, I
Speaker 1: suddenly get a picture of that fingerprint, you would just yeah,
Speaker 1: that's that's the way. I think that the iPhone five
Speaker 1: S and the Galaxy something something that the latest Samsung
Speaker 1: incorporates it. And UM PayPal these days even has UM
Speaker 1: fingerprint signatures on their app, and any any device that
Speaker 1: allows you to in to scan in your fingerprint will
Speaker 1: yeah let you pay for stuff on PayPal with that signature.
Speaker 1: I'm sure we're going to see a lot of that
Speaker 1: kind of stuff incorporate with things like the NFC technology
Speaker 1: or even the low Bluetooth energy low energy bluetooth. Rather,
Speaker 1: I should say, implementations where your fingerprint instead of having
Speaker 1: to put in a pen, you just swipe your finger. Yeah,
Speaker 1: you know, I don't know. I kind of hope that
Speaker 1: it's an additional safety feature, not a standalone safety feature,
Speaker 1: because you know, unlike a password or a pin, you
Speaker 1: can't just change your fingerprint if it gets stolen. And
Speaker 1: this hash issue add security to to the whole thing.
Speaker 1: It's harder to but I'm sure that someone if they
Speaker 1: really wanted to, could decode a hash and figure out
Speaker 1: what that scan looks like. Yeah. Maybe, I mean, they
Speaker 1: would have to have a lot of information, but it
Speaker 1: is It is important to say that there is no
Speaker 1: security feature out there that's going to be right right,
Speaker 1: There's nothing out there, So having it as an additional tool,
Speaker 1: I agree, Lauren, that's that's the best way of looking
Speaker 1: at it. I think anytime we decide that we're going
Speaker 1: to rely on a specific implementation and that's it and
Speaker 1: we're done, we're good, then we're pretty much dooming ourselves
Speaker 1: to getting hacked in some way down the line. And
Speaker 1: that wraps up this classic episode about biometrics. It's still
Speaker 1: a very very big topic, arguably an even bigger topic
Speaker 1: today than it was back in very complicated. There's so
Speaker 1: many things to take into consideration from security and privacy
Speaker 1: issues too. You know, the problems with authentication in some cases,
Speaker 1: ways to work around biometrics. There's a lot going on there.
Speaker 1: I will likely do more episodes kind of diving into
Speaker 1: not just the tech but the ethics behind biometrics. If
Speaker 1: you have suggestions for topics I should cover in future episodes,
Speaker 1: let me know the best way to do that is
Speaker 1: over on Twitter. The handle is text stuff H s
Speaker 1: W and I'll talk to you again really soon. Y
Speaker 1: tex Stuff is an I Heart Radio production. For more
Speaker 1: podcasts from my Heart Radio, visit the i Heart Radio app,
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