Speaker 1: Brought to you by Toyota. Let's go places. Welcome to
Speaker 1: Forward Thinking either everyone, and welcome to Forward Digging, the
Speaker 1: podcast that looks at the future and says you spend
Speaker 1: me right round, baby, right round. I'm job in Strickland,
Speaker 1: I'm Lauren, and I'm Joe McCormick. So, guys, have you
Speaker 1: ever needed to, you know, have a nice, quiet, secure
Speaker 1: communication with someone or something? Yeah, I might need to
Speaker 1: have a secure communication. Let's say if I'm dealing with
Speaker 1: an Internet seller, So maybe a seller on Etsy who
Speaker 1: has created glass handcrafted Star Wars action figures with with
Speaker 1: with stained tinted coloring and oddly specific. That sounds precarious
Speaker 1: but beautiful. Yeah, it's also not what I thought you
Speaker 1: were gonna say, because internet seller, I thought you were
Speaker 1: either talking about someone who sells in nets or perhaps
Speaker 1: or perhaps a dark basement of the Internet exactly. But
Speaker 1: now I've got you all right, So a vendor, a
Speaker 1: merchant on the Internet, and you want to make a transaction,
Speaker 1: you will hear all my special numbers, right. You would
Speaker 1: want those special numbers to say yeah, but you would
Speaker 1: not want those special numbers to get out and about
Speaker 1: to the general public, where they could all make their
Speaker 1: own nefarious purchases using your hard earned money. Right, they
Speaker 1: could go buy their own glass memorabilia or or let's
Speaker 1: let's say that you are just trying to send a
Speaker 1: message to someone and you don't necessarily want the entire
Speaker 1: world to understand what exactly you are saying. You know, right,
Speaker 1: like things right, right, Like if if I wanted to
Speaker 1: send Lauren an email talking smack about a certain other
Speaker 1: host of this show, um, and I didn't want that
Speaker 1: host to be privy to all the things I had
Speaker 1: to say about him. Sure, yeah, And of course no
Speaker 1: one believes this because you just talked smack right out loud.
Speaker 1: But alright, that's but hypothetically, if you didn't want me
Speaker 1: to know, I'm sorry, you didn't want this other host
Speaker 1: to know, then this would be important. You would want
Speaker 1: to be able to hide the information. Thus, Uh, this
Speaker 1: is of course not new to the internet. You know,
Speaker 1: the idea of being able to hide information so that
Speaker 1: you can send messages, uh, discreetly, secretly. This is not
Speaker 1: something that's that's brand new. This is an ancient idea.
Speaker 1: Oh no, of course, I mean secrets are power, it's
Speaker 1: the it's one of the main things we've got going
Speaker 1: for us as a species. We've learned how to leverage
Speaker 1: privileged information. Yes, you know something they don't know. When
Speaker 1: that gives you an advantage, right, Uh, you know obviously
Speaker 1: if you are able to maintain that advantage, then that
Speaker 1: gives you, uh well, prolonged advantage. You don't want that
Speaker 1: to suddenly become common knowledge because then suddenly it's a
Speaker 1: it's a level playing field again, and who knows, some bigger,
Speaker 1: stronger person is going to come around and take all
Speaker 1: your stuff. So in the in the ancient world, we
Speaker 1: use things called ciphers, which allowed us to uh to
Speaker 1: jumble up a message so that only the person who
Speaker 1: sends it and and the person who receives it ideally
Speaker 1: have any chance of figuring out what that messages. Now,
Speaker 1: that just might mean that you have an agreed upon
Speaker 1: set of rules, which means when you get a message,
Speaker 1: you look at the message, the jumbled up message, and
Speaker 1: you apply those set of rules to it to unscramble
Speaker 1: it and see what the actual message is. Right. So
Speaker 1: the dirt simplest version of this would be just say,
Speaker 1: like an alpha numeric scramble, So you say A is
Speaker 1: one and B is two, and you write, you translate
Speaker 1: your message in whatever language you're writing into numbers. Right,
Speaker 1: the same kind of thing that you probably did to
Speaker 1: obscure notes when you were passing them in class when
Speaker 1: you were in like elementary school. Right, And he's a
Speaker 1: B and a besa C. No one's ever going to
Speaker 1: figure it out. Yeah, Yeah, these are all very common,
Speaker 1: very simple ciphers. Now in the world of the Internet,
Speaker 1: in the world of computers, these sort of things don't
Speaker 1: don't fly. It's not going to work anymore because it's
Speaker 1: pretty easy to figure that one out. So we're talking
Speaker 1: about specifically, uh, cryptography in general, which is the whole
Speaker 1: science of making stuff secret, and then encryption in particular,
Speaker 1: which is an implementation of cryptography. And the reason why
Speaker 1: I say that is that frequently people will interchange these
Speaker 1: two terms, but they do mean different things. We'll probably
Speaker 1: do it on this podcast. Everybody uses encryption, cryptography, cryptology
Speaker 1: that they'll get jumbled up, right, And and I admit,
Speaker 1: I mean I do this all the time. I it's
Speaker 1: not because I don't appreciate that there are differences. It's
Speaker 1: just that my brain starts taking shortcuts and then I
Speaker 1: get less accurate in my description. But yes, cryptography the
Speaker 1: overall field encryption a specific implementation of cryptography where you
Speaker 1: are encrypting a mess it's using some sort of cipher
Speaker 1: or key, and then someone else has to use a
Speaker 1: decoder key to get at the original message. And if
Speaker 1: everything is cool, then you don't have to worry about
Speaker 1: anyone else intercepting that message and knowing what's going on.
Speaker 1: But the problem is, things aren't really cool in the
Speaker 1: real world, are they not. When you send a message
Speaker 1: to somebody, it's generally, I think assumed within the world
Speaker 1: of cryptography that you should always just take as an
Speaker 1: assumption that somebody's listening. Yes, I mean we're we're living
Speaker 1: in a world now where it is incredibly easy for
Speaker 1: people to listen in, whether on purpose or not. I
Speaker 1: remember like this this applies to lots of different fields,
Speaker 1: not just Internet communication. It could be a telephone, right,
Speaker 1: I remember using wireless telephones where occasionally it would pick
Speaker 1: up conversations other people were having that because the channel
Speaker 1: as were close enough where I was getting interference and
Speaker 1: I was so eventually one one part of one of
Speaker 1: the conversations would kind of go like hello, right, is
Speaker 1: that are we who else is here? Or I would
Speaker 1: talk into it and then it would be clear that
Speaker 1: the other parties on the line couldn't hear me. But
Speaker 1: yet I was like, well, I don't want to listen
Speaker 1: in uh, but I would like to make a phone call.
Speaker 1: So I'm going to go and use one of the
Speaker 1: hard lined phones that I have instead of one of
Speaker 1: these super cheap early eighties wireless monstrosities. Of course, your
Speaker 1: hardline phone can be tapped just as easily, or someone
Speaker 1: in another branch of the house could pick up another
Speaker 1: receiver of it. Right, So in this case, we are
Speaker 1: going to be talking about some some famous people. Uh,
Speaker 1: those famous people are not really people. There are actually
Speaker 1: their names are placeholders for any two entities that wish
Speaker 1: to exchange information. This would be Alice and Bob. You
Speaker 1: may have heard of Alice and Bob. Alie and Bob. They're,
Speaker 1: like I said, placeholders. You want you it's so that
Speaker 1: you can give examples so people can wrap their heads
Speaker 1: around the way this kind of secret communication works. So
Speaker 1: it's not Alice in Wonderland and Bob Seeker. It's I mean,
Speaker 1: it could be we might, sure, but we're talking about
Speaker 1: a third person as well, we're talking also about Eve. Yes,
Speaker 1: Eve would be a short for Eve's dropper clever huh
Speaker 1: Sole See what they did there. Eve wants to listen
Speaker 1: in on this conversation between Alis and Bob for whatever reason.
Speaker 1: Doesn't matter. We're just talking about, you know again, concepts here. Eve. Also,
Speaker 1: it does not necessarily have to be an actual conscious
Speaker 1: person or entity. No, Eve could be a computer. Eve
Speaker 1: could also just be an environment because in this case,
Speaker 1: when we get into uh A later in the podcast,
Speaker 1: we're gonna be talking about the type of cryptography that
Speaker 1: um has some limitations around it, and the environment can
Speaker 1: actually play a role in messing up that cryptography. But
Speaker 1: in general, we think of Eve as some entity trying
Speaker 1: to get intercept messages, usually in the middle between Alison Bob,
Speaker 1: to try and decipher exactly what is going on. Okay, So,
Speaker 1: in the world today, if Alison Bob want to have
Speaker 1: a totally private conversation that nobody else can know about
Speaker 1: over the Internet, what is the main way we're going
Speaker 1: to use to communicate privately? Uh That would be using
Speaker 1: key encryption, a public key and a private key. This
Speaker 1: is based off something called r s A encryption. It's
Speaker 1: actually uh, that named after the folks who came up
Speaker 1: with it. But the idea here is that you have
Speaker 1: a public key that allows people to encode messages that
Speaker 1: are going to be sent to you, and then you
Speaker 1: have a private key that allows you to decode those messages.
Speaker 1: And then if you want to send a message back
Speaker 1: to someone, you use their public key to encode it
Speaker 1: and they'll use their own private key to decode it.
Speaker 1: So the public key is something you can send out
Speaker 1: to the world and it's fine because all it does
Speaker 1: is in code messages. It doesn't decode anything um And
Speaker 1: the private key you keep to yourself and you don't
Speaker 1: let anyone get hold of it because obviously that would
Speaker 1: mean they could decode any message meant for you. So
Speaker 1: in this case, if Alice once said Bob a message,
Speaker 1: Alice would use Bob's public key, Bob would use his
Speaker 1: private key to decode it. Then if Bob wanted to respond,
Speaker 1: he would use Alice's public key, Alice would use her
Speaker 1: private key to decode it. Theoretically, everything should remain safe. Okay,
Speaker 1: but wait a second, how do these keys actually work together?
Speaker 1: Because I wonder if there's a way to exploit this process. Um,
Speaker 1: it's it's interesting that you asked that question. So there
Speaker 1: are different ways to create encryption keys, but one of
Speaker 1: the most popular is prime factorization. Tell me how it works. Okay,
Speaker 1: you know what a prime number is, right, It's a
Speaker 1: number that is only divisible by itself and one. That's correct.
Speaker 1: So if you were to take a two prime numbers,
Speaker 1: So figure out two prime numbers, uh, three and seven?
Speaker 1: All right, and then you multiply the two of those
Speaker 1: together you get all right. So if I gave you
Speaker 1: just the twenty one and I told you it's your
Speaker 1: job to figure out which two prime numbers I used
Speaker 1: to multiply together to get to twenty one, you would
Speaker 1: have to start going through and looking at the divisors
Speaker 1: for twenty one and figuring it out. Now, that one's
Speaker 1: pretty easy, right, But when you get into very large numbers,
Speaker 1: there's a lot of different possibilities. Yeah. Yeah, it might
Speaker 1: be worth dwelling for a minute on why that's hard
Speaker 1: to do. There's no just simple equation for how to
Speaker 1: get those prime numbers. You have to try them one
Speaker 1: at a time. So you have to take, okay, is
Speaker 1: two times two, that's not twenty one? Okay, two times three,
Speaker 1: that's not twenty. Really, you would just say to one,
Speaker 1: is twenty one divisible divisible by two? And if so
Speaker 1: is the other? Uh? Is the other number also a prime?
Speaker 1: So you can do it that way. So you take
Speaker 1: twenty one and you say, all right, let's go to
Speaker 1: by two. All right, that's that doesn't work. Twenty one
Speaker 1: divide by three. That gets seven. Wait a minute, three
Speaker 1: and there are both prime numbers, so that'd be pretty easy.
Speaker 1: But yeah, but if you if you're talking about enormous
Speaker 1: prime numbers, and when I say enormous, I'm talking about
Speaker 1: something that has maybe you know, forty digits or more
Speaker 1: behind it. You know, that's a huge prime number or
Speaker 1: you know, huge prime number, and you multiply it by
Speaker 1: another huge prime number that has an equal number of
Speaker 1: digits behind it. You get an incredibly enormous product. And
Speaker 1: this is the basis of your encryption. Uh. Then working
Speaker 1: backwards trying to figure out which two prime numbers made
Speaker 1: that product is incredibly difficult. It would take a classical
Speaker 1: computer working on a single core processor years, maybe centuries
Speaker 1: to figure it out. I've heard it often expressed that
Speaker 1: it would take more than a person's lifetime to solve
Speaker 1: these on a classical machine. Yeah. So the three guys
Speaker 1: that came up with this, their last names were Rivest
Speaker 1: still are Rivest, Shamir, and Adelman. So you've got that, uh,
Speaker 1: And they were the ones who who came up with
Speaker 1: this this general idea which has been used extensively since then.
Speaker 1: And um, basically that's the the idea you use. You've
Speaker 1: got this product which you can then allow people to
Speaker 1: encode things. Um using this, you know, it's kind of
Speaker 1: like another mash up type deal. The coded message gets
Speaker 1: sent to you. Because you have the the actual prime
Speaker 1: numbers that were used to make that product, you can
Speaker 1: decode the message. If you don't have those two prime numbers,
Speaker 1: you can't decode it. So that's the general idea. And
Speaker 1: because it's such a hard problem that computers normally would
Speaker 1: take a very long time to solve, it was considered
Speaker 1: extremely secure. Well but is it still extremely secure? If
Speaker 1: if it's so difficult to crack, then well, how is
Speaker 1: it vulnerable? It depends on It depends on the determination
Speaker 1: and resources of your eve that that's exactly right. So
Speaker 1: the reason it's secure is because of the limitations of computers.
Speaker 1: But if you were just to say, imagine you had
Speaker 1: a computer that was way, way, way, way way more
Speaker 1: powerful than your standard computer today, this problem would start
Speaker 1: becoming a lot less of a problem. And in fact,
Speaker 1: we can sort of create these situations today by say,
Speaker 1: teaming up a lot of computers together. Right, if you
Speaker 1: either had a supercomputer that had lots and lots of
Speaker 1: processing cores, and you created a program to look for
Speaker 1: the prime, uh the factorization of any number, and you
Speaker 1: allowed it so that it could take advantage of all
Speaker 1: those processor course and start solving things in parallel, you
Speaker 1: cut down on the amount of time it's going to
Speaker 1: take to do the overall problem because you've got multiple
Speaker 1: cores all working on this. Or if you are able
Speaker 1: to link together a bunch of computers to essentially do
Speaker 1: the same thing, where each computer is working on part
Speaker 1: of this problem. Let's say that a computer just has
Speaker 1: a a chunk of numbers that it's looking at as
Speaker 1: it goes through. I'll take the first thousand prime numbers,
Speaker 1: and Joe across the network. You take the next thousand, Yeah,
Speaker 1: and you're you've got you know, maybe hundreds of computers
Speaker 1: in this network. This is something that someone with a
Speaker 1: zombie army, a botan net could do. They've infected a
Speaker 1: bunch of computers. They're using their processors to do whatever
Speaker 1: one of those things could be, to try and do
Speaker 1: a brute force attack. That's what we call it, because
Speaker 1: you're using just brute computing force to go through all
Speaker 1: the potential possibilities to try and find the actual two
Speaker 1: numbers that were used to multiply together and make that product. Yeah,
Speaker 1: you're just doing trillions and trillions of calculations spread out.
Speaker 1: But even with this approach, R s A is still
Speaker 1: pretty secure. But just because of the scale of the
Speaker 1: math involved, the kinds of computers we have today, even
Speaker 1: if we imagine these brute force scenarios, it's still pretty secure.
Speaker 1: It is pretty secure if you've got someone who's really,
Speaker 1: really determined and they're using an advanced computer, especially one
Speaker 1: that is able to take advantage of graphics processors, which
Speaker 1: you know, graphics processors are meant to process graphics on
Speaker 1: your computer. But a lot of hackers have been using
Speaker 1: it as a way of creating another avenue for brute
Speaker 1: force attacks. It's something that is possible to crack, it's
Speaker 1: not easy to do, and it's still is going to
Speaker 1: take time, depending upon you know, how resourceful that hacker is,
Speaker 1: how many machines they might have at their disposal. But
Speaker 1: it's it's one of those things where you know, the
Speaker 1: more the larger year numbers that you're using in your encryption,
Speaker 1: the more time is required or the more processing powers
Speaker 1: required to break that encryption, and the less likely it's
Speaker 1: going to happen because the number of people who have
Speaker 1: that capability and that desire starts to shrink. You know,
Speaker 1: the more complex it gets, the fewer people are going
Speaker 1: to say, yeah, that's worth my time. Sure. But okay,
Speaker 1: So we're living in the incredible future, right and we
Speaker 1: we have or we are starting to develop, at any rate,
Speaker 1: computers that are different from the classical computers that we
Speaker 1: have been talking about. We've talked on this very show before,
Speaker 1: in fact, about quantum computers computer so you know we
Speaker 1: talked when we talked about quantum computers, one of the
Speaker 1: things we discussed is how they might not really even
Speaker 1: provide an advantage if you're just talking about wanting to
Speaker 1: stream video and send emails and browse the web. So
Speaker 1: why on earth would somebody want to build a quantum
Speaker 1: computer if it doesn't provide an advantage of those things. Well, yeah,
Speaker 1: I mean it's it's not necessarily going to help your
Speaker 1: twitch skills at call of duty. But what it could
Speaker 1: do is allow you to solve certain types of problems
Speaker 1: much more quickly than you would with a classical computer.
Speaker 1: But like these problems specific exactly because you've got cubits. Cubits, yeah,
Speaker 1: as opposed to bits, right, So a bit is a
Speaker 1: bit of data. It's a zero oral one. It's kind
Speaker 1: of like an on or off switch or an often
Speaker 1: on switch off your time zero and one. Uh. Cubits
Speaker 1: are quantum bits, and one of the properties of the
Speaker 1: quantum world is called superposition, where you can have a
Speaker 1: quantum particle that can inhabit multiple states simultaneously. So, for example,
Speaker 1: we talk about photons and their spin, and we'll talk
Speaker 1: about them more in a minute, but photon can have
Speaker 1: various types of spin, vertical, horizontal, diagonal. In the quantum state,
Speaker 1: it can have all of these simultaneously in superposition. So
Speaker 1: a cubit can be both a zero and the one
Speaker 1: at the same time, and technically all values in between.
Speaker 1: So if you have cubits and you have enough of them,
Speaker 1: like you have a quantum computer that has a lot
Speaker 1: of cubits, you can then solve certain really difficult problems
Speaker 1: like prime factorization, all in parallel, because it's essentially this
Speaker 1: is oversimplifying, but essentially doing all the calculations simultaneously. So
Speaker 1: at any rate, if you've got a quantum computer that
Speaker 1: has a significant enough number of cubits, then in theory,
Speaker 1: you could break this kind of prime factorization problem in
Speaker 1: no time. Okay, But but I mean quantum computers, although
Speaker 1: they do exist. I mean, who has the time, or
Speaker 1: the money, or the resources or the desire to possibly
Speaker 1: own such a fascinating and and rare piece of machinery.
Speaker 1: Who also wants to know all of our secrets? We've
Speaker 1: now entered into the Jonathan Lauren and Joe get On
Speaker 1: some more government lists part of the podcast. Uh yeah,
Speaker 1: the n s A. Yeah. So it turns out, among
Speaker 1: the many things we learned from the leaked documents that
Speaker 1: Edward Snowden provided about the n s A, one of
Speaker 1: the things was we discovered a seventy nine point seven
Speaker 1: million dollar research project known as Penetrating Hard Targets of
Speaker 1: the n s A, and it was very interested in
Speaker 1: building quote a cryptologically useful quantum computer. So I hope
Speaker 1: you like your email with the side of spying, because
Speaker 1: this is on the way. The n s A has
Speaker 1: specifically expressed interest in creating quantum computers that can do
Speaker 1: that brute force mathematical attack to decode your encrypted messages. Right,
Speaker 1: it's essentially going to sit there and make private keys.
Speaker 1: The private public key encryption technique that we've really been
Speaker 1: reliant upon for more than a couple of decades now
Speaker 1: completely useless. It will essentially be one of those things
Speaker 1: that if they direct their attention to you, they will
Speaker 1: be able to break that key and read all everything
Speaker 1: that's coming to you. Right. And so part of the
Speaker 1: problem is, because all of this research is classified, we
Speaker 1: don't know how far along they are on this path.
Speaker 1: I mean, you might think that they're ahead of where
Speaker 1: the private labs are today, or you might think they're
Speaker 1: running neck and neck with them. We don't really know,
Speaker 1: but we at least know that they are really interested
Speaker 1: in this and are willing to spend money on it. Okay,
Speaker 1: but part of part of the game here, you know,
Speaker 1: you're always going to have people who are trying to
Speaker 1: keep something secret and people who are trying to figure
Speaker 1: those secrets out, and as the technology of of one increases,
Speaker 1: the other has to in order to compete. So you know,
Speaker 1: there are people who are working on creating quantum cryptography
Speaker 1: to help solve this entire problem for us, right, Yeah,
Speaker 1: So we go to another quantum technology basically to offset that.
Speaker 1: So the secret breakers are going to get a big
Speaker 1: advantage with quantum computers, but only because we are using
Speaker 1: classical computers to set up our original encryption. If we
Speaker 1: move to ye, a quantum system of of being able
Speaker 1: to hide what we're saying. Actually, well, yeah, it's a
Speaker 1: quantum framework. You can still use classical computers to to
Speaker 1: do the communication. Yeah, you need you need a quantum
Speaker 1: emitter is what you're gonna need. I can actually explain
Speaker 1: what we're talking about here with quantum cryptography, at least
Speaker 1: on a high level. When you get down to it,
Speaker 1: you start getting into quantum weirdness that I know happens.
Speaker 1: But that's different from saying I understand it, right, Okay,
Speaker 1: So I have a pretty good way I think of
Speaker 1: getting into how quantum cryptography works. And so it's this question,
Speaker 1: why even use a public key in the first place,
Speaker 1: Why can't you just share a private key between Alison Bob,
Speaker 1: so they've got a a private uh decode or algorithm
Speaker 1: known only to them, and then they just use that.
Speaker 1: Why even put half of that key out there for
Speaker 1: people to use in a brute force attack. Well, the
Speaker 1: answer is kind of obvious because in order to do that,
Speaker 1: they'd have to share the private key over the Internet.
Speaker 1: If someone's eavesdropping like Eve, and Eve intercepts the private key,
Speaker 1: then even you've just given Eve the magic decoder ring
Speaker 1: to decode all the messages. Right, So ideally, the best
Speaker 1: case scenario would be that Alison Bob have a private
Speaker 1: key known only to them. But that really only works
Speaker 1: in the real world if I don't know, if they
Speaker 1: share it somehow physically in the same location, if they
Speaker 1: go up to each other and whisper it to one
Speaker 1: another in a completely darkened and sound proof room. If
Speaker 1: perhaps at one thirty in the morning, Alice here's a
Speaker 1: gentle scratching near the window, sees Bob outside whispering it's time.
Speaker 1: Obviously that is not practical. If, say, the if you
Speaker 1: are the Alice and the Bob you want to communicate with,
Speaker 1: is some store online that you want to do business with.
Speaker 1: You're not going to go meet up somewhere, you might
Speaker 1: as well just do the transaction in the physical place.
Speaker 1: I I sometimes do go up to brick and mortar
Speaker 1: stores at one thirty in the morning and whisper into
Speaker 1: their walls yes, and they say no, it's the secrets,
Speaker 1: will be all right. So getting away from the creepy
Speaker 1: and into the actual how does this work? But anyway,
Speaker 1: so ideally you would have a private key. Well, quantum
Speaker 1: key distribution is a way we have figured out to
Speaker 1: do exactly that, to share a private key without Eve
Speaker 1: being able to intercept it. And it's all because it
Speaker 1: relies upon the laws of quantum physics, not on just
Speaker 1: zeros and ones. Zeros and ones come into play because
Speaker 1: that again is the basis for computing, and we haven't
Speaker 1: created a new model of computing, so we're still reliant
Speaker 1: upon that. But how do we generate a key that
Speaker 1: would allow us to encode and decode messages based on
Speaker 1: zeros and ones, but transmitted in such a way that
Speaker 1: it is impossible for an eavesdropper to pick up on it.
Speaker 1: And that's where we get this quantum key distribution. That's
Speaker 1: really the other way of saying quantum cryptography. A lot
Speaker 1: of people think of it as quantum encryption, which is
Speaker 1: not what's going on. There's no quantum element to the
Speaker 1: encryption because by the time you've gotten to the point
Speaker 1: where you actually have a key, all the quantum stuff
Speaker 1: is over. You're done with the quantum. Well, I'm sure
Speaker 1: I've said quantum encryption a ton of times. That's why
Speaker 1: I'm specifically addressing it now. But if we've said that
Speaker 1: in the past, and specifically if I wrote those words
Speaker 1: in the video, I don't know if I did, but well,
Speaker 1: even if you didn't, I may have said them. Okay, Well,
Speaker 1: in any case, what we mean there is quantum key
Speaker 1: distribution using these quantum principles to create a private key.
Speaker 1: So here's what's going on. Because we we've danced around
Speaker 1: it enough and now now I get the the unenviable
Speaker 1: task of trying to explain this. So all right, Alison Bob,
Speaker 1: we still have Alison Bob. Alice wants to send Bob
Speaker 1: a private message, but first she has to establish this
Speaker 1: private key between the two of them, And like you said, Joe,
Speaker 1: you can't just send a private key through classical channels
Speaker 1: and expect it to get there without someone looking at it.
Speaker 1: That always assume heve's listening, right, So how does Alice
Speaker 1: do this? She ends up setting up two different channels
Speaker 1: of communication. You have a quantum channel of communication and
Speaker 1: a classical channel of communication. So in real life, this
Speaker 1: quantum channel of communication would probably be some kind of
Speaker 1: fiber optic transmission or a way of transmiss transmitting a photon. Yes, photons,
Speaker 1: particles of light. Like we said, the particles of light
Speaker 1: have this, uh, this this quality spin where they can
Speaker 1: be spinning vertically, horizontally or diagonally. So beforehand, Alice and
Speaker 1: Bob have determined which spins will mean a one versus
Speaker 1: a zero, so you might say vertical spins, those are ones,
Speaker 1: horizontal spins or zeros, diagonal spins one way or a one,
Speaker 1: diagonal spins the other way, or a zero. So now
Speaker 1: they know which one is gonna be a one or
Speaker 1: a zero. Then what Alice does is she sets up
Speaker 1: a photon emitter an l e ed would be a
Speaker 1: good one, uh, and then starts to generate photons one
Speaker 1: by one. Now when she generates them, they are they
Speaker 1: have the superposition where they've got all spins at once.
Speaker 1: This is unpolarized light. She then puts it through a
Speaker 1: filter which polarizes the light, either a vertical, horizontal, or
Speaker 1: diagonal filter. This gives the photon a specific spin. It
Speaker 1: eliminates all the other possibilities. She then starts to transmit
Speaker 1: these photons one by one to Bob, changing filters as
Speaker 1: she's going to whatever pattern or random group she wants. Now,
Speaker 1: Bob is receiving these photons and he's passing them through
Speaker 1: filters of his own. His filters come in two flavors.
Speaker 1: He's got a filter that will allow either vertical or
Speaker 1: horizontal uh spin to come through, and he has another
Speaker 1: filter that will allow diagonal spin to come through either
Speaker 1: direction of diagonal spin. So what happens if the wrong
Speaker 1: type of polarized photon hit If a polarized photon hits
Speaker 1: the opposite type of so filter. If he has a
Speaker 1: diagonal filter and a either horizontal or vertical spin photon comes,
Speaker 1: it will not pass through that filter and he'll get
Speaker 1: a a fail. Essentially, he will say that he does
Speaker 1: not know what that particular number will be, but that's okay,
Speaker 1: that's fine. In fact, he just keeps on going and
Speaker 1: just the random chance fifty of the time he's going
Speaker 1: to end up getting a filter that works properly with
Speaker 1: this uh, with this this one that Alice sent. That's
Speaker 1: just based upon you know, a long enough string and probability,
Speaker 1: because he's you know, he's he can get half of
Speaker 1: what is sent on the other half he wouldn't. So
Speaker 1: over a long enough string, you're gonna see success rate.
Speaker 1: So then at that point Alison Bob through their classical
Speaker 1: channels start to go through, and Bob says, all right, here,
Speaker 1: here are the filters that I used in order, and
Speaker 1: then Alice will say yes or no, as in, yes,
Speaker 1: that's the right kind of filter for you to have used,
Speaker 1: or no it is not. And then by that way
Speaker 1: they established which bits made it through, because again they've
Speaker 1: already agreed if a vertical spin is a one and
Speaker 1: horizontal spin is a zero. So once they have enough
Speaker 1: information about which ones passed through, they have a string
Speaker 1: of ones and zeros. You eliminate all the x is,
Speaker 1: all the ones where Bob used the wrong filter, and
Speaker 1: then you would you should have enough information there to
Speaker 1: create a key to encrypt things. However, if during this
Speaker 1: classical communication, Alice starts to say, you know what, Bob,
Speaker 1: you haven't gotten any right at all, and that's really weird.
Speaker 1: That's an indication that someone has been snooping. Because one
Speaker 1: of the facets of quantum, the quantum world, is that
Speaker 1: by observing, you change the observed right. So if Eve
Speaker 1: is trying to intercept this private key between Alice and Bob,
Speaker 1: Eve is actually changing that photon spin and creating a
Speaker 1: string of photons have exactly the right spin to send
Speaker 1: it onto Bob. Is not a practical solution. So in
Speaker 1: other words, Eve ends up changing the key before he
Speaker 1: can get to Bob. And but because the key, because
Speaker 1: those changes are detectable, Alison Bob would know if someone's
Speaker 1: been listening, and if they know that, they know to
Speaker 1: abandon that key and to start over, right. So the
Speaker 1: safety comes in, uh, the awareness of Alice and Bob.
Speaker 1: It's not that Eve couldn't tap this line. It's that
Speaker 1: Alie and Bob will always, because of the laws of
Speaker 1: quantum mechanics, be able to tell if you taped. And
Speaker 1: this is just to make that key right. There's no
Speaker 1: information that's going across yet. Alice hasn't said, hey, Bob,
Speaker 1: what's for dinner? She hasn't written any kind of message.
Speaker 1: They're just trying to establish what is the key they're
Speaker 1: going to use to encode and decode messages. And because
Speaker 1: once they established that they have completely symmetrical keys, they're
Speaker 1: identical keys, I shouldn't say symmetrical, they're identical, then they
Speaker 1: know that they can encode and decode perfectly, and then
Speaker 1: they can send over classical channels using that private key.
Speaker 1: I mean, it's almost as if they had met up
Speaker 1: and agreed on a key and then went back their
Speaker 1: separate ways, right, because they're establishing a key safely over
Speaker 1: this classical channel of communication, and there's there's no way
Speaker 1: to determine what that key was because in order to
Speaker 1: know what the key was, you had to have received
Speaker 1: those photons. But if you receive the photons, you changed
Speaker 1: the photons. So that means that the other recipient, the
Speaker 1: actual intended recipient would have been, would have caught onto it,
Speaker 1: and again they would have abandoned it and started again.
Speaker 1: So Eve would eventually either frustrate Alison Bob to the
Speaker 1: point where Alison Bob, well, we're just not going to communicate,
Speaker 1: or Eve would get frustrated and quit trying to eavesdrop
Speaker 1: because it wasn't productive. She's never going to get anything
Speaker 1: other than the attempts to create a secure private key, Right,
Speaker 1: it's pointless on eves Park. Yes, there's another approach though, right,
Speaker 1: which has to do with spooky action at a distance.
Speaker 1: I hadn't even heard about this one, so I'm intrigued
Speaker 1: to see what you're gonna say. So, Yeah, the other
Speaker 1: spooky action is called quantum entanglement. This is where you
Speaker 1: can create a pair of quantum particles like photons, and
Speaker 1: they will have identical um identical features in some way,
Speaker 1: and when you measure one, you will know exactly what
Speaker 1: the state is of the other particle at the moment
Speaker 1: that it was measured. Right, So they're entangled. And then
Speaker 1: you can take them to opposite ends of the galaxy
Speaker 1: and you look at one, and by looking at at
Speaker 1: that one, you will immediately know something about the other
Speaker 1: one at the other end of the galaxy. Now, from
Speaker 1: that point on you can't determine anything, right, because you've
Speaker 1: changed the system by looking at it. Yeah, they're unentangled,
Speaker 1: wrecked everything. Yes, everything you touch you destroy, which pretty
Speaker 1: much true in the quantum world. So um, So the
Speaker 1: idea I saw, and this was more of a hypothetical.
Speaker 1: This is not typically how it's more typical that's done
Speaker 1: in that filtering system that I had just talked about.
Speaker 1: But hypothetically you could create a set of entangled photons.
Speaker 1: I believe you would have to measure them exactly at
Speaker 1: the right time to be able to determine what that
Speaker 1: sequence was, so that Alice and Bob would have identical
Speaker 1: private keys. Because here's the thing is, if you observe one,
Speaker 1: then they become unentangled. So let's say Alice goes ahead
Speaker 1: and observes her string of photons. Bob has not looked
Speaker 1: at his string of photons, but once Alice does, then
Speaker 1: they become unentangled, and whatever Bob says won't match what
Speaker 1: Alice has anyway, So I'm not sure exactly how the
Speaker 1: implementation would work, but hypothetically they have talked about using
Speaker 1: they being quantum scientists talked about using these strings of
Speaker 1: entangled particles in order to create identical private keys. That again,
Speaker 1: if an eavesdropper gets hold of one of them just
Speaker 1: by looking at them, they become unentangled and they are
Speaker 1: no longer useful as a private key. In the first place,
Speaker 1: so fascinating. Don't know what the implementation would be yet.
Speaker 1: I I understand the filtering one more than I understand
Speaker 1: this one. Both of them are pretty dense. Once you
Speaker 1: get down to the technical level. Oh yeah, No, once
Speaker 1: you get down to like, all right, well, why is
Speaker 1: this happening, you get a lot of I'm always I'm
Speaker 1: always comforted that quantum physicists themselves usually kind of go
Speaker 1: like yeah, you get to a point where they're like, yeah, okay,
Speaker 1: I don't know anymore, Well, there's gonna be. They're really
Speaker 1: smart people. They can describe what's happening really well. Yeah.
Speaker 1: When when you start asking them why, either like, well
Speaker 1: that's a great question. Why not? Okay? But I wanted
Speaker 1: to point out something that's really cool about quantum cryptography,
Speaker 1: which is that this is not some far future, pie
Speaker 1: in the sky fantasy, is it. No, the idea was today. Yeah,
Speaker 1: the ideas were mentioned back in the eighties. I mean this,
Speaker 1: this idea has been around for for like twenty five
Speaker 1: years um in some form or another. It's not used widely, no, yeah,
Speaker 1: because it does have some pretty tough limitations. Obviously, we're
Speaker 1: talking about these quantum states. They are very delicate. Uh,
Speaker 1: and again, any kind of disturbance of that state is
Speaker 1: going to have an effect and thus make this private
Speaker 1: key sharing um an impossibility. So yeah, you're limited by
Speaker 1: how far you can transmit this information without danger of
Speaker 1: the photons getting quote unquote lost along the way. So
Speaker 1: it's a matter of kilometers, right, and maybe a few
Speaker 1: dozen kilometers. But it's not like coast to coast. You
Speaker 1: could not have a coast to coast fiber optic cable
Speaker 1: as of right now and expect that quantum state to
Speaker 1: be preserved for the entire length of that that cable,
Speaker 1: and so it would be really difficult to share a
Speaker 1: private key across that way. Yeah. I also want to
Speaker 1: introduce some other considerations that we should take into account
Speaker 1: because a lot of people are are looking at quantum
Speaker 1: cryptography and they're saying, amazing, it's unhackable. And I actually
Speaker 1: do agree with them in theory because because of the
Speaker 1: way it's constructed based on the laws of quantum physics,
Speaker 1: it is in theory unhackable. The principle is completely sound.
Speaker 1: The implementation, on the other hand, we don't know. I mean,
Speaker 1: because that's a problem that's often come up in cryptography before.
Speaker 1: For example, we've had major uh security scares on the
Speaker 1: Internet that had nothing to do with the soundness of
Speaker 1: public key encryption. Oh sure, so you're talking specifically about
Speaker 1: heart bleed, right, So yeah, looking at the heart bleed bug.
Speaker 1: Oh man, everybody had to change their passwords. It was panic.
Speaker 1: But the problem wasn't that somebody had found a way
Speaker 1: to decode all of your public key encryption. No, it
Speaker 1: was a bug. It was it was a vulnerability um
Speaker 1: in in open SSL. That's secure socket layer, which is
Speaker 1: a type of security measure that's in place over a
Speaker 1: great deal of Internet websites, like many many servers, not
Speaker 1: not all, but yeah, something like six that we're using
Speaker 1: that form of security. We're using that specific, specific type. Now,
Speaker 1: open SSL had several versions. You know, it's kind of
Speaker 1: like any other software where you get generations of the software,
Speaker 1: you know, one point oh one point oh one, one
Speaker 1: point two, that kind of thing, unless you're Mac and
Speaker 1: then it's ten point ten for reasons that never mind,
Speaker 1: I'm going to go off on a tangent. So at
Speaker 1: any rate, the problem in certain versions of open SSL
Speaker 1: was in something that they called a heartbeat, and the
Speaker 1: purpose of the heartbeat was really just to say hey,
Speaker 1: are you still there? And the other services yeah, and
Speaker 1: then everything's fine. Except instead of just saying hey, are
Speaker 1: you still there and the services yeah, the server responds
Speaker 1: with whatever the original message was going to be, right,
Speaker 1: It's it's sort of like asking hey, Jonathan, if you're
Speaker 1: still there, say yes, and then I would say yes,
Speaker 1: but but but if you but if instead a tricksy
Speaker 1: person gets in there and says, hey, Jonathan, I'm tots
Speaker 1: the server. Are you still there? If so, say yes,
Speaker 1: but say it in characters. Yeah. So in this case,
Speaker 1: what was going on was that the message going out
Speaker 1: to the server was uh, was short. The actual message
Speaker 1: was short, but the meta data about the message said
Speaker 1: it was much longer. So, in other words, if I
Speaker 1: send out a request to a server and say hit
Speaker 1: me back to let me know you're still there, Um,
Speaker 1: this is the message, and the message is only three
Speaker 1: characters along, but it says it's five characters long, then
Speaker 1: the server is going to say, all right, I'm still here.
Speaker 1: Here your message, but then says, wait a minute, the
Speaker 1: number of characters I put in here is four short
Speaker 1: of what it should be. Oh, I'll just fill it up.
Speaker 1: With whatever random stuff happens to be in my memory
Speaker 1: to pad it out. It's kind of like it's it's
Speaker 1: kind of like cheating, right, You're like, like, oh, they
Speaker 1: expect to have a thick envelope back, I'm just gonna
Speaker 1: shove a whole bunch of blank pieces of paper or
Speaker 1: random things. But yeah, and and so sometimes those random
Speaker 1: things would be people's passwords or private keys, or private
Speaker 1: keys or lots of other wacky information. Yeah. So if
Speaker 1: you targeted a server that, for instance, handled email exchanges,
Speaker 1: and you got a bunch of random information in from
Speaker 1: the server's memory, some of that random information could be
Speaker 1: private keys that would allow you to decrypt things as
Speaker 1: if you were that person. Right, it's not like you
Speaker 1: were using a hack. You were just using that person's key.
Speaker 1: It's like you had found a key and made a
Speaker 1: copy of it yourself, and you're using that key to
Speaker 1: get in and out of that person's house. Same sort
Speaker 1: of thing. So you could do it completely undetectable by
Speaker 1: anybody else. And uh, people began to panic by changing
Speaker 1: their passwords. But the problem was changing your password doesn't
Speaker 1: solve that problem. You would have to have the the
Speaker 1: on the server side you would have to have administrators
Speaker 1: patched the server open SSL approach to to a version
Speaker 1: that did not contain that that that bug, and then
Speaker 1: change your password. Yes, it was only after it had
Speaker 1: been patched that changing your password would matter at all. Right,
Speaker 1: So the analogy of all this to quantum cryptography is
Speaker 1: that even though the principle might be completely sound, you
Speaker 1: can always have something like the heart bleed bug. Well,
Speaker 1: you can always have a problem with the specific way
Speaker 1: you designed this system. It might be a hardware problem.
Speaker 1: Maybe the way you're using uh, the way you're emitting
Speaker 1: photons or something is vulnerable to detection. Here's an easy way,
Speaker 1: here's an easy way that would that would totally ruin it. So,
Speaker 1: you know, we talked about Alice and Bob, and we're
Speaker 1: talking about them comparing filters. All of that would obviously
Speaker 1: be automated. You wouldn't actually have two people physically putting
Speaker 1: filters in place and physically checking that that system. So
Speaker 1: I think, I see where you're going. Are you talking
Speaker 1: about if you could control the filters they use, or
Speaker 1: you don't have to control the filters they use, what
Speaker 1: you because even that would be a little weird. But
Speaker 1: what you could do is if you were not careful
Speaker 1: in the way you designed the software, you could have
Speaker 1: it where Alice and Bob are exchanging in order to
Speaker 1: confirm that the message has gone over, exchanging too much information,
Speaker 1: revealing what that string of numbers actually is. You know
Speaker 1: what the idea is that you're sharing information about the process,
Speaker 1: but not about the actual zeros and ones. Right, You're
Speaker 1: you're kind of talking around the problem so that you
Speaker 1: can both figure out which ones and which zeros came
Speaker 1: through without actually saying, oh, it's one zero zero one one,
Speaker 1: because that would be useless. You would essentially be doing
Speaker 1: the same thing as sending the private key. But it
Speaker 1: could be eas lee be where someone creates this this
Speaker 1: sort of approach and has an implementation that reveals too
Speaker 1: much about the actual key and gives people enough of
Speaker 1: a hint to make it useless. Yeah, I've seen some
Speaker 1: people say also that the process, the security of the
Speaker 1: process in the long term, will depend on our ability
Speaker 1: to create truly random numbers. Uh. And so if you
Speaker 1: have a number that's supposed to be random, but it's
Speaker 1: actually not random, right, because folks, random number generators usually
Speaker 1: are not actually random. No, it's they're they're random ish.
Speaker 1: They're so complexly derived that they seem random to us.
Speaker 1: Uh yeah, because I mean it's hard to program a
Speaker 1: computer to say, make up a number without telling the
Speaker 1: computer how does it make up a number? It usually
Speaker 1: has to pull information from something. There's some really cool
Speaker 1: examples of doing that by using things like environmental factors,
Speaker 1: like well, the barometric pressure is such, and the wind
Speaker 1: direction as such, and so those things are going to
Speaker 1: mean that I multiply these two umbers together to get
Speaker 1: your random number, which is kind of cool because it's
Speaker 1: based on a chaotic system, but still still not still
Speaker 1: an algorithm and not actually right. Yeah. I want to
Speaker 1: introduce another concern on top of that, which is that
Speaker 1: so there may be design flaws, but we'll trust that, Okay,
Speaker 1: the people designing these systems are probably very, very smart,
Speaker 1: and they're taking a lot of precautions. And let's say
Speaker 1: they do design a foolproof system. You know what they
Speaker 1: can't do. They can't design foolproof users. Yeah. Now, this
Speaker 1: is always going to be a problem. So one of
Speaker 1: the things that we see over and over again is
Speaker 1: that a lot of systems they're supposedly secure, end up
Speaker 1: becoming vulnerable, not because of some inherent flaw or because
Speaker 1: a hacker was able to crunch numbers enough times to
Speaker 1: get into a system, or that someone has created a
Speaker 1: weird program where you type in three guesses on a
Speaker 1: password and the third one is always right Hollywood, But
Speaker 1: but rather because you know that guy from Seinfeld has
Speaker 1: created a backdoor that's going to let all of the
Speaker 1: dinosaurs eventually run a buck on the island. Kind of Yeah,
Speaker 1: the more like more like the idea of, Hey, I
Speaker 1: wonder what Lawrences password is. Let me pick up this
Speaker 1: this keyboard. Oh, sure enough, there's a post it note
Speaker 1: with a password on it, or a much easier one, say,
Speaker 1: if you're not in the same office, is I send
Speaker 1: Jonathan and email saying Hey, I'm the new assistant to
Speaker 1: your system administrator and I need your password in order
Speaker 1: to do some maintenance on your computer. Yeah. This is
Speaker 1: called social engineering. It's manipulating the people in a system
Speaker 1: rather than the technology, and often it ends up being
Speaker 1: the most effective way of getting access to any secure system.
Speaker 1: If you read any reports about some of the famous hackers,
Speaker 1: a lot of their exploits involved not to use a
Speaker 1: pun A lot of their exploits involve manipulating people not
Speaker 1: sitting down at a computer and typing in zeros and
Speaker 1: ones until things magically happened. Right. Well, typically the people
Speaker 1: are the weakest part of the whole process. Yeah, that's
Speaker 1: why I I I anticipate wiping them all out and
Speaker 1: making a perfect, clean future where I don't have to
Speaker 1: worry about these weaknesses, where dinosaurs rule the earth. All right,
Speaker 1: well this got dark fast. No, obviously I'm not going
Speaker 1: to wipe out people. Who's who's going to carry all
Speaker 1: my stuff? What would you eat? It would be really
Speaker 1: lonely going to the same restaurants over and over again,
Speaker 1: all by myself and robot waiters saying table for one again. Yeah,
Speaker 1: so yeah, I probably won't do that. No, it's not
Speaker 1: putting it on the back burner, but anyway, Yeah, it's
Speaker 1: it's true. Any system, any secure system, you need to
Speaker 1: look at the people as well as the technology and
Speaker 1: make sure the people know the best practices for remaining
Speaker 1: secure and private so that other people who want to
Speaker 1: get access to that stuff don't have as easy a
Speaker 1: time about it. The harder we make it, the less
Speaker 1: likely it'll happen. It doesn't mean that someone who's really
Speaker 1: determined won't find a way. Now, the quantum cryptography approach
Speaker 1: is really darn secure because that's basic laws of physics that,
Speaker 1: as far as we know, are unbreakable. So if we
Speaker 1: can get the physical systems to take advantage of those
Speaker 1: laws of quantum physics, we got it made. But we
Speaker 1: already are seeing limitations right now, and it's just, you know,
Speaker 1: there's still questions about whether or not this could ever
Speaker 1: be a widely implemented security feature. You know, it might
Speaker 1: be something that we see in something like a military
Speaker 1: installation where the different machines on that installation use quantum
Speaker 1: cryptography to communicate with each other. But if I'm sending
Speaker 1: an email to a buddy of mine who lives out
Speaker 1: in California, there may not be a physical system that
Speaker 1: can take advantage of this, but just because the very
Speaker 1: nature of the quantum world. So there, you know, things
Speaker 1: to think about. But I really think this was an
Speaker 1: interesting topic. It's great to UH to kind of explore it,
Speaker 1: especially since we always love looking at the quantum world
Speaker 1: and marveling at how unusual it is, how how alien
Speaker 1: it is to us on the macro level. So we
Speaker 1: love those kind of topics, and this is where I
Speaker 1: invite you, our listener, if you have any interesting topics
Speaker 1: that are future oriented, whether it is a technology you
Speaker 1: want to know about, or some development in science, or
Speaker 1: some big question about what what is culture and society
Speaker 1: gonna be like in a hundred and fifty years, or
Speaker 1: even hey, there's this other thing that science fiction films
Speaker 1: never address and I really want to know about it.
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