[00:07.340 --> 00:08.880]  All right, I show the time is 1,200.
[00:09.460 --> 00:15.840]  That means we must be here at the presentation by number 75, Karamoon.
[00:16.200 --> 00:18.880]  But before he begins his presentation, I want to make a couple announcements.
[00:19.460 --> 00:29.680]  First of all, Kevin Mitnick's presentation tonight at 1,700 hours has been switched with the off-the-hook, uncensored version.
[00:30.080 --> 00:32.520]  So that will be going on tonight, off-the-hook, uncensored.
[00:33.140 --> 00:34.000]  Is it 8 o'clock?
[00:37.970 --> 00:38.870]  Yeah, 1,200.
[00:39.110 --> 00:40.470]  Watch out there, number 316.
[00:42.030 --> 00:43.570]  All right, so thank you.
[00:44.450 --> 00:47.090]  That will be switched with Off The Hook.
[00:47.310 --> 00:49.650]  Mitnick will be tomorrow at the same time.
[00:49.670 --> 00:51.890]  So those two have just reversed if you want to correct that in your guide.
[00:52.070 --> 00:54.790]  We'll keep announcing it anyway, but please enjoy.
[00:55.490 --> 00:59.370]  I also have a note that at 1,700, that's... what's going on?
[00:59.670 --> 01:05.750]  Presentation at 1,700 has been canceled, and it's going to be biometrics and science fiction here in this room at 1,700.
[01:05.750 --> 01:08.050]  So if you're interested in that, I hope to see you back then.
[01:08.910 --> 01:14.750]  For now, we have number 75, Karamoon, talking about the life and times of Alan Turing.
[01:16.490 --> 01:16.890]  Okay.
[01:16.890 --> 01:17.290]  Cool.
[01:21.050 --> 01:22.890]  Just a quick show of hands.
[01:23.090 --> 01:26.430]  Like, how many people could confidently give a talk on Turing's life?
[01:26.590 --> 01:28.490]  I'm just curious, like, the level of knowledge.
[01:29.210 --> 01:29.930]  Okay, a few.
[01:30.090 --> 01:30.410]  That's good.
[01:32.070 --> 01:35.270]  It's nice that actually people have at least some interest in him.
[01:36.070 --> 01:38.530]  I just thought it was really important that this talk was given.
[01:38.930 --> 01:43.210]  I think it's really important people, you know, know who Turing was and why he's important to us.
[01:44.470 --> 01:55.370]  And it's kind of funny that we really need to explain this to people, because as we're going to see through my talk, he's a really fundamental character in the history of computing and lots of other subjects as well.
[01:57.010 --> 01:58.010]  I'm Karamoon.
[01:58.250 --> 02:06.750]  I'm involved in a whole bunch of things, but I mainly hang out on the Super Dimension Fortress, which is one of the oldest public access UNIX systems going.
[02:06.870 --> 02:08.070]  I think we've been going since 1984.
[02:08.630 --> 02:11.770]  I can see a few SDFers in the audience, which is really good.
[02:12.710 --> 02:13.490]  Please join.
[02:13.670 --> 02:14.190]  It's free.
[02:14.330 --> 02:16.930]  You just tell net to sdf.lonestar.org.
[02:17.750 --> 02:24.250]  A really big, exciting project we've got going at the moment is called The Non, which is essentially a parallel non-commercial Internet.
[02:25.170 --> 02:28.250]  A big project and, you know, worth looking into.
[02:30.790 --> 02:33.530]  Why did I bother talking about Turing, really?
[02:33.730 --> 02:36.990]  Why am I going to take an hour of your time to talk about this English dude?
[02:39.530 --> 02:43.350]  First of all, like I said before, not a huge number of people are familiar with him.
[02:43.350 --> 02:52.230]  Even people that are, you know, quite involved in the computing scene and hacking scene still seem in the dark about what Turing did and why he's so important to us.
[02:54.030 --> 03:03.090]  A lot of people describe him as being the father of the modern computer, and I'll go through why he's described him that way and why I think it's a valid description.
[03:04.230 --> 03:10.930]  A really big thing is that, depending on who you believe, some of us would be not here if it wasn't for him.
[03:11.650 --> 03:17.710]  Turing was one of the key figures in breaking the German Enigma code, which I'll be talking about in relative detail.
[03:18.910 --> 03:25.910]  Some military historians think it probably shortened the war by three years, you know, which is a lot of lives.
[03:26.270 --> 03:29.590]  So, you know, possibly we wouldn't be here if it wasn't for him.
[03:30.290 --> 03:32.870]  And the human rights issue is interesting as well.
[03:33.310 --> 03:34.930]  Turing was a victim of persecution.
[03:36.010 --> 03:38.950]  And it's quite a tragic tale that I'm going to be telling today.
[03:38.950 --> 03:46.310]  So, it's a good example to give people of why we need to fight for human rights now and not wait until it's too late.
[03:49.410 --> 03:52.230]  Sources on Turing are kind of actually hard to come by.
[03:52.830 --> 03:54.490]  There's a few reasons for this.
[03:55.310 --> 03:57.130]  In England, he sort of...
[03:57.130 --> 04:00.750]  I think there is still some embarrassment surrounding him.
[04:01.370 --> 04:06.610]  There's embarrassment that he died in the way that he did, which I'll be explaining later.
[04:07.950 --> 04:11.070]  We have lots of security issues in England, i.e.
[04:11.110 --> 04:14.390]  the people that make security laws are just crazy, really.
[04:14.530 --> 04:19.410]  We have things like the 40-year rule, which says that big secrets should stay secret for 40 years.
[04:20.330 --> 04:24.070]  So, a lot of the papers and information on Turing is only just coming available.
[04:24.330 --> 04:25.810]  We also don't have fair use.
[04:27.270 --> 04:31.630]  I know in the U.S., fair use is, you know, quite a big issue.
[04:31.630 --> 04:33.750]  But in the U.K., we just... we don't have it.
[04:33.910 --> 04:38.370]  There's no, like, copyright exemption for educational stuff, generally.
[04:39.570 --> 04:43.770]  I mean, something as simple as photocopying a map, you're allowed, like, 10% of a map.
[04:44.030 --> 04:44.550]  That's it.
[04:44.770 --> 04:45.550]  That's quite serious.
[04:45.770 --> 04:50.050]  So, the main sources on Turing are a bunch of books that people have written by him.
[04:51.690 --> 04:53.050]  Again, a quick show of hands.
[04:53.130 --> 04:55.270]  Who's read all four of those books?
[04:56.470 --> 04:56.910]  Anyone?
[04:57.570 --> 04:58.450]  Okay, cool.
[05:00.110 --> 05:06.010]  And I guess I'd say that the book that most of you may have read is Godel Escher-Bach.
[05:06.290 --> 05:07.530]  How many people have read that?
[05:08.130 --> 05:08.910]  Okay, cool.
[05:09.330 --> 05:11.810]  That's the main book that introduces people to Turing.
[05:12.770 --> 05:20.250]  As the title suggests, it's about Kurt Godel, who is a Czech mathematician, I believe, M.C.
[05:20.330 --> 05:21.890]  Escher and Johann Sebastian Bach.
[05:22.870 --> 05:31.010]  Throughout the book, the Turing machine, which was Turing's theoretical computer, is used as an example of how computing and artificial intelligence works.
[05:31.690 --> 05:37.590]  The code book is an excellent book by a British journalist, all about history of code breaking.
[05:38.150 --> 05:43.810]  Turing, the enigma, is the main source of information on Turing by a guy called Hodges.
[05:44.050 --> 05:50.830]  A massive, massive research project over many, many, many years, is continually revising his book.
[05:51.570 --> 05:52.550]  It is fantastic.
[05:52.850 --> 05:53.930]  It's quite biased.
[05:54.250 --> 05:56.490]  I'll kind of explain about that later as well.
[05:56.790 --> 06:00.190]  He's a very bitter man, Hodges, as some of you may know.
[06:00.410 --> 06:01.530]  I hope he's not here.
[06:03.750 --> 06:07.010]  If you want to go to a bookstore, you could find those books.
[06:08.430 --> 06:11.430]  Yeah, the Hodges one is really worth reading.
[06:11.550 --> 06:12.050]  Massive.
[06:12.210 --> 06:13.750]  It's like 500 pages.
[06:13.750 --> 06:16.650]  The print is like a quarter of the size of an orbrook.
[06:16.790 --> 06:18.810]  So it's good for eyestrain.
[06:20.150 --> 06:25.210]  Okay, so Alan Turing was born in 1912 in the U.K.
[06:25.670 --> 06:30.630]  His parents were quite insistent that he was born in the U.K., although he was conceived in India.
[06:31.010 --> 06:39.190]  His dad was involved in the military and the foreign office and the East India Shipping Company booth.
[06:40.330 --> 06:46.510]  Turing went to school in a public school, which is a private school with a strange nomenclature in England.
[06:48.010 --> 06:51.910]  And he exhibited what a lot of us would probably call hacker traits.
[06:53.070 --> 06:58.210]  You know, kind of a loner, a bit of an interesting guy.
[06:58.470 --> 07:03.790]  He was quite sort of oblivious to how the systems around him worked and the system in which he was living.
[07:03.790 --> 07:06.690]  And that's a theme that runs throughout his life.
[07:08.030 --> 07:17.390]  Sort of a cross between being oblivious and not giving a damn, which is probably quite a cool way to live, really, except it may have cost him his life in the end.
[07:17.810 --> 07:19.630]  We'll talk about that later.
[07:20.350 --> 07:21.250]  Die for freedom, yeah?
[07:21.350 --> 07:21.850]  It's worth it.
[07:23.750 --> 07:26.730]  So Turing was at this private school.
[07:26.970 --> 07:30.870]  He was really good in science, pretty poor in the other subjects.
[07:31.870 --> 07:35.390]  He went on to excel in science, and the school really wasn't satisfied.
[07:35.770 --> 07:39.950]  The school was trying to turn out well-rounded English gentlemen.
[07:41.330 --> 07:43.390]  This was British Empire time.
[07:44.350 --> 07:48.970]  These are the people that were going to go and make the planet ours.
[07:49.230 --> 07:55.610]  It was quite a scary thought, really, in these times, with the current U.S. administration and my good friend, Tony Blair.
[07:57.530 --> 08:01.850]  So Turing got out of school and got into King's College, Cambridge.
[08:04.170 --> 08:07.150]  He was not massively happy about that.
[08:07.370 --> 08:09.310]  He was aiming for Trinity College.
[08:09.570 --> 08:15.470]  The reason he was aiming at Trinity College was, at school, he fell in love with a guy called Morecambe.
[08:16.650 --> 08:20.190]  And homosexuality is kind of quite a big theme in his life.
[08:20.890 --> 08:23.910]  And again, which was probably the main thing that cost him his life in the end.
[08:24.710 --> 08:31.630]  And he had this sort of oblivious and not giving a damn kind of attitude to it, which was quite cool.
[08:34.750 --> 08:38.390]  Hard as it may be to believe, King's College was quite...
[08:38.390 --> 08:42.670]  King's College in the 30s was like quite an anarchistic haven, really.
[08:43.770 --> 08:49.670]  Hodges describes it as being amoral in the truest sense, that the people there were really...
[08:50.970 --> 08:55.490]  had the mindset that every case, every issue, they would judge on its merits.
[08:55.490 --> 08:58.130]  They didn't feel constrained by external laws.
[08:59.170 --> 09:11.090]  In 1933, the union of King's College passed a motion saying that they would never go to war for king or country, which is quite a serious thing to say in England.
[09:11.090 --> 09:15.410]  England, you know, in our fascist, totalitarian country.
[09:15.870 --> 09:27.510]  You know, they were saying that, yeah, they could possibly go and kill some people in the area of security, but, you know, it was no longer good enough to go out and die for your beloved country.
[09:27.990 --> 09:30.550]  I think Turing was quite happy at King's.
[09:30.970 --> 09:33.390]  It was quite an amazing atmosphere there.
[09:35.990 --> 09:37.950]  Basically, he was doing research.
[09:37.950 --> 09:39.330]  He was doing a bit of teaching.
[09:40.830 --> 09:42.510]  Just generally having a cool time.
[09:43.090 --> 09:50.470]  And in particular, in King's, because it was sort of an anarchistic community, homosexuality just wasn't an issue.
[09:50.730 --> 09:53.710]  People would sort of turn a blind eye, unlike the rest of society.
[09:53.930 --> 09:55.630]  It was kind of quite a cool place to hang out.
[09:57.970 --> 09:59.270]  Turing was really a mathematician.
[09:59.770 --> 10:03.390]  We can't really say he was a computer scientist because he invented computer science.
[10:03.990 --> 10:05.190]  So we can't really say that yet.
[10:05.190 --> 10:13.030]  He was interested in some really, really deep maths that has massive implications for how computing and how programming work.
[10:13.590 --> 10:16.130]  He was interested in things like Godel's incompleteness theorem.
[10:17.190 --> 10:24.830]  That's a really important result in mathematics that says that systems can either be complete or powerful, but not both.
[10:25.590 --> 10:35.470]  Kurt Godel was a brilliant mathematician, really f*cked things up for mathematicians by proving that, in some senses at least, it's all a waste of time.
[10:37.010 --> 10:39.090]  The way he did it was really interesting.
[10:39.550 --> 10:44.310]  He looked at proof, the idea of proof, and looked at proofs for things.
[10:44.310 --> 10:56.010]  And he realized that, a bit like maybe an object-oriented program where we look at the study of nouns, he thought proofs could be treated as nouns, and in particular as numbers.
[10:56.310 --> 11:04.130]  So he thought he could number the proofs and then find some properties of those numbers that were consistent with them being valid proofs.
[11:04.210 --> 11:09.990]  And then he could create some numbers that fitted within the system but weren't for valid proofs.
[11:10.810 --> 11:13.670]  So he was really interested in the study of paradox and stuff.
[11:14.310 --> 11:20.330]  I'm sure most of you have read things like Principle Mathematica, so I won't go into a lot of detail on that.
[11:22.190 --> 11:25.150]  But Godel's stuff is really interesting, really worth looking into.
[11:26.630 --> 11:27.810]  Kind of really touches on...
[11:27.810 --> 11:30.270]  goes into the nature of truth.
[11:30.870 --> 11:34.550]  The nature of infinity was something that really interested Turing.
[11:34.830 --> 11:42.490]  And it's something that is actually really important in looking at computer programming and whether programs will terminate in particular.
[11:44.510 --> 11:52.110]  Infinity turns out to be quite different from what you expect in the popular mathematical press, for example.
[11:52.470 --> 11:55.730]  We generally think of infinity as being an infinitely huge number.
[11:56.330 --> 11:59.690]  It turns out there are a wide variety of types of infinity.
[12:01.130 --> 12:09.990]  A simple example is if you take the number one and number two and you look at all the fractions in between, you find that there's an infinite number of fractions in between.
[12:09.990 --> 12:13.490]  Yeah, you could just keep dividing into smaller and smaller and smaller slices.
[12:14.450 --> 12:18.870]  So between the numbers one and two, you have an infinitely dense number line.
[12:20.230 --> 12:28.810]  But then we can find other numbers that fit between one and two, but on fractions, like the square root of two, which is an infinite decimal.
[12:29.630 --> 12:31.710]  So that's sandwiched in between one and two.
[12:32.050 --> 12:33.810]  And yet we've said one and two are infinitely dense.
[12:33.970 --> 12:37.950]  So you've got like an infinitely dense chunk of the number line with some holes in.
[12:38.650 --> 12:41.490]  So infinity is not what it seems, really.
[12:41.710 --> 12:47.230]  And it's quite important in computability, which was really a concept that Turing came up with.
[12:48.450 --> 12:53.050]  There are a whole bunch of challenges in mathematics proposed by a guy called Hilbert.
[12:53.930 --> 12:58.130]  He did something kind of quite cool and also really lazy.
[12:58.350 --> 13:12.130]  When he was coming up for retirement, instead of not retiring and doing something worthwhile, he thought he'd just write a whole bunch of challenges and, like, just say to the world, do all this stuff to progress in mathematics.
[13:12.470 --> 13:20.370]  So we wrote, like, this big list of problems and said any one of these problems that we managed to solve pushes back the boundaries of mathematics.
[13:21.770 --> 13:30.310]  Godel solved two of those problems by saying that maths doesn't really work as a concept.
[13:31.630 --> 13:34.510]  And Turing went on to solve the halting problem.
[13:34.690 --> 13:36.470]  The halting problem is quite interesting, really.
[13:36.830 --> 13:43.990]  When you... I'm sure you've written computer programs that go into loops and you think, that's really annoying.
[13:44.190 --> 13:47.470]  I'll go and read some books and try and work out what happened.
[13:49.090 --> 13:59.530]  In general, if you wanted to see if a computer program is going to go into an inflow loop, you might think, well, we'll write another computer program and, like, read through the code, like, parse through the code.
[14:00.930 --> 14:04.250]  And Turing was thinking about this idea.
[14:04.350 --> 14:05.610]  Obviously, not with computer programs.
[14:05.930 --> 14:11.110]  When Turing talks about computers in his papers, there obviously were no computers.
[14:11.270 --> 14:12.370]  There was no concept of a computer.
[14:12.830 --> 14:19.230]  So a computer meant someone who sat down at a table with a bunch of paper and a pen, crunching, you know, doing number crunching it, basically.
[14:19.790 --> 14:27.050]  Turing was very interested in the idea of methods, formal methods for doing things like the, essentially, what we now call algorithms.
[14:27.330 --> 14:30.090]  He basically came up with the concept of the algorithm.
[14:31.850 --> 14:33.050]  So we've got an algorithm.
[14:33.270 --> 14:34.370]  We want to see, does it work?
[14:34.510 --> 14:36.190]  Is it going to just get into a continuous loop?
[14:36.350 --> 14:44.410]  So we might have another algorithm, possibly in our head, i.e., we would read through the code.
[14:44.410 --> 14:45.970]  And we'd go through the code step by step.
[14:45.990 --> 14:47.710]  And we'd think, what's happening in this code?
[14:47.750 --> 14:48.510]  Is it going to loop?
[14:50.090 --> 14:52.330]  We might replace ourselves with a computer program.
[14:52.390 --> 14:56.030]  We might have a computer program that goes through parsing through code, seeing if it's going to loop.
[14:57.070 --> 15:04.250]  However, very quickly, you should see a problem, which is that we're writing a program to parse the program.
[15:04.270 --> 15:06.330]  But how do we not know our program is not going to loop?
[15:06.670 --> 15:09.850]  So you get these layers and layers and layers and layers of programs.
[15:10.630 --> 15:14.010]  And this is a really key thing that Turing works out.
[15:14.890 --> 15:20.050]  That just formal methods are probably limited in their power.
[15:21.530 --> 15:26.070]  One thing Turing was really interested in was, like, the concept of the soul.
[15:26.250 --> 15:33.110]  He was brought up as a Christian, like most people were, and yet became quite a strong atheist in the end.
[15:33.110 --> 15:37.810]  It's quite interesting to look through his life, the sort of things that made him change his mind.
[15:38.730 --> 15:48.710]  And I think he and a lot of other people, in the breaking points of mathematics, and particularly in the breaking points of physics, people saw God.
[15:49.730 --> 16:07.390]  I'm sure most of you have seen people or read about quantum theory, and people using this as a justification for saying humans have free will and all that nonsense, which we don't obviously... anyone with a basic knowledge of physics knows that.
[16:08.890 --> 16:27.570]  Things like quantum spontaneity and quantum electronics and stuff were seen as a real opportunity to kind of win back our lives from science, to say, you know, hold on, there are these random things in science, this quantum spontaneity of things just happening,
[16:27.730 --> 16:29.610]  these probability fields, stuff like this.
[16:31.350 --> 16:47.210]  Another thing Turing was just randomly interesting was density of primes, because it's a really nice, difficult problem in maths, and the sort of thing that you think should be quite solvable with a formal method.
[16:47.210 --> 17:02.790]  So the density of primes is quite simple, that as the numbers get bigger and bigger and bigger, the primes get fewer and fewer and fewer, which intuitively sort of makes sense, because with a big number, there are far more numbers below it that could be multiplied together to get that number.
[17:03.670 --> 17:06.570]  So sort of on an intuitive level, it seems to make sense.
[17:07.990 --> 17:20.930]  And Turing was really interesting in the idea of making a formal method that could prove that primes do get much less dense as we go along the number line.
[17:21.410 --> 17:26.850]  So he uses that as a sort of problem throughout most of his life, really.
[17:27.370 --> 17:34.390]  And as he comes up with the concept of the computer, it's something that he really wants to tackle, and he does in a hardware way.
[17:36.570 --> 17:45.690]  One of the reasons that at least some people have heard of the Turing is the Turing machine, which was his idealized kind of concept of a computer.
[17:46.290 --> 17:48.250]  The Turing machine is really, really interesting.
[17:48.250 --> 17:51.510]  It looks really, really simple, but it's quite a deep concept.
[17:54.110 --> 17:58.630]  Turing thought about how we solve problems, in particular, how do we do mathematics.
[17:59.070 --> 18:08.710]  And he thought about someone sitting at a table with loads of paper and some pens, and how would they do number crunching, how would they solve problems, how would they do proofs.
[18:09.130 --> 18:17.050]  And he tried to think of what he could cut away from that picture to get the real essence of how we do mathematics or how we solve any problems.
[18:17.310 --> 18:18.890]  And he came up with the Turing machine.
[18:19.510 --> 18:27.730]  And the idea of the Turing machine is that you have an infinitely long tape with squares, and you have a head that can read the squares.
[18:27.730 --> 18:33.970]  So, some of the squares may have characters on, the head can erase the characters, the head can write more characters.
[18:35.910 --> 18:46.210]  The machine has a whole bunch of states, and depending on what state it's in depends what it will do to the next character it comes across, or the next square it comes across.
[18:46.870 --> 19:09.290]  The interesting thing about the Turing machine is that it's quite easy to extend the idea into a machine with lots of tapes and lots of tape heads, or two-dimensional tapes instead of this one-dimensional tape, or machines that at each point can branch off and make various decisions.
[19:11.190 --> 19:15.990]  The really nice thing about the Turing machine is that you see this multi-headed Turing machine.
[19:16.150 --> 19:23.750]  Actually, any Turing machine, no matter how complicated, you can always condense it down to the idea of a single head with a long tape.
[19:27.050 --> 19:35.270]  Turing thought about this machine, and he thought about writing a description of the machine, what the machine does, how it does it.
[19:35.270 --> 19:39.970]  So he came up with the idea of a Turing table, so you have a Turing machine.
[19:40.290 --> 19:43.770]  You might have a Turing machine, for example, that adds numbers together.
[19:44.010 --> 19:50.770]  It goes along the tape, reads a number, reads the next number, adds them up, writes the third number here, writes the answer.
[19:53.170 --> 19:56.790]  So he's got the idea of these tables, and tables describing machines.
[19:56.930 --> 20:05.770]  And he thought, I could get one of these tables and feed it into another Turing machine, and get the Turing machine to sort of mimic the first Turing machine.
[20:05.870 --> 20:15.670]  So we'd get like an addition Turing machine, write down its description, get a multiplication Turing machine, write down its description, get a Microsoft Word Turing machine, write down its description.
[20:16.330 --> 20:23.350]  And we'd feed these descriptions into what became known as the universal Turing machine, that could mimic any other Turing machine.
[20:23.350 --> 20:43.170]  So these descriptions are essentially computer programs who came up really with the true concept of computer program and the universal computer, which is quite different from things like Babbage's calculating machine and Lovelace's kind of programs and things like the looms.
[20:43.170 --> 20:49.650]  You know, the early computers were based on looms for weaving, and you'd feed it in a pattern about weaving.
[20:51.310 --> 21:06.010]  But it could really only do fixed steps and could only follow whatever was on the pattern, whereas Turing really came up with this idea of computer programs that could be fed into universal Turing machines.
[21:07.350 --> 21:22.930]  And, one kind of interesting side issue is that, sort of intrinsic in the idea of the Turing machine, is the idea that a Turing machine can modify its own code, because the code it follows is on this tape and it can erase the characters and it can write characters,
[21:23.210 --> 21:25.990]  so intrinsically in the concept.
[21:25.990 --> 21:31.130]  It's quite a powerful compute programming concept, the idea that it can go through and change its own code.
[21:32.610 --> 21:42.690]  So, despite the fact that the Turing machine might seem quite an abstract concept, it is sufficiently powerful to be a decent description of a computer.
[21:48.650 --> 21:57.350]  Some of you may have also heard of the Turing test, popularised by the Voikampf test in Blade Runner.
[21:58.590 --> 22:00.430]  So, you've all seen Blade Runner, yeah?
[22:01.010 --> 22:02.830]  Okay, that's everyone just nodded.
[22:06.610 --> 22:10.070]  A Voikampf test is a test to see if someone's an android or not.
[22:10.610 --> 22:14.230]  It's quite a problem in society today with all these androids walking around.
[22:15.350 --> 22:19.090]  You shouldn't laugh because there could be an android sitting next to you.
[22:19.430 --> 22:22.310]  If you had a Voikampf machine, then you could tell.
[22:23.050 --> 22:28.470]  The Voikampf machine just looks at the physical responses in the body.
[22:28.470 --> 22:36.050]  and uses that to determine whether the person is human or is an android.
[22:37.730 --> 22:53.510]  Turing, who lived a little bit before Blade Runner was made, he invented the idea of the Turing test and he rejected looking at the physical attributes because he didn't think that was really an important aspect of intelligence.
[22:54.550 --> 22:58.730]  Now, Voikampf is just to test if something is human.
[23:00.010 --> 23:05.270]  Turing's test is either wider or more restrictive depending on your philosophy.
[23:05.830 --> 23:08.750]  Turing's test was to test if something is intelligent.
[23:09.610 --> 23:16.250]  And Turing's test is very nice because it kind of allows us to not muck around with defining what intelligence is.
[23:16.250 --> 23:20.570]  It's a very, very simple idea based on something called the imitation game.
[23:21.910 --> 23:24.470]  In the imitation game, you have a man and a woman.
[23:26.050 --> 23:28.890]  And they're hidden from you behind screens or whatever.
[23:29.070 --> 23:31.970]  And you can pass them the questions and you can get the responses.
[23:32.210 --> 23:34.230]  And you have to work out who's the man, who's the woman.
[23:34.230 --> 23:41.130]  And it's really not a good... this is like the example Turing based his test on.
[23:41.210 --> 23:42.390]  It's really not a good example.
[23:42.590 --> 23:50.410]  So the Turing test, we replace one of the people with a computer and we try and find out which one is a computer program and which one is a human.
[23:51.970 --> 24:08.130]  The man and woman concept doesn't really work very well because Turing essentially says that if it's sufficiently difficult that we can't tell which one is the computer program, which one is the person, then the computer program can be said to be intelligent.
[24:09.550 --> 24:19.750]  This is why the man and woman thing doesn't really work because most of you would say that if you couldn't guess whether someone's a man or woman, it doesn't mean that they're the same thing.
[24:20.830 --> 24:27.430]  So maybe Turing was a little bit misguided with his example in his papers on the Turing test.
[24:28.570 --> 24:34.590]  The Turing test is really, really relevant today and it's really relevant to people in interest in security.
[24:34.850 --> 24:38.170]  So it's quite important to test if people are human or not.
[24:40.490 --> 24:42.070]  Many of you have used Capture.
[24:42.290 --> 24:44.550]  Many of you have used... who's used Capture today?
[24:45.650 --> 24:46.110]  Okay, yeah?
[24:46.310 --> 24:47.970]  So quite a few of you know what it is.
[24:48.250 --> 24:52.090]  Completely automated public Turing test to tell computers and humans apart.
[24:54.210 --> 25:06.530]  Capture are those annoying little boxes you get when you post messages to email lists maybe through a web interface or you sign up for anything on the web.
[25:06.530 --> 25:09.970]  You get a little box with some jumbled up letters and you've got to type in the letters.
[25:10.550 --> 25:15.270]  This is essentially a Turing test because the computer program is trying to test whether you're human or not.
[25:17.530 --> 25:29.630]  And it's kind of ironic and pretty sad that these are widespread throughout the net and that they're really testing whether they're human or not because certain people fail those tests all the time.
[25:29.950 --> 25:31.710]  Visually impaired people, for example.
[25:32.190 --> 25:34.270]  They're human, in my opinion.
[25:34.270 --> 25:38.770]  But obviously not according to people who invented Capture.
[25:39.830 --> 25:47.030]  So from a security point of view it's quite interesting to be able to tell if an entity is a human or if it's a computer.
[25:47.310 --> 25:51.170]  And maybe intelligence is quite a good way to test this.
[25:52.650 --> 25:55.590]  Some of you may have been at the CCC last year.
[25:57.950 --> 26:01.630]  There was a talk on biometrics and fingerprint scanners.
[26:03.110 --> 26:08.330]  And basically fingerprint scanners are what sort of security engineers term a bunch of crap.
[26:09.510 --> 26:17.890]  Fingerprint scanners generally run at like 600 DPI and any fool can make a latex finger to beat a fingerprint scanner.
[26:18.070 --> 26:27.190]  So there's lots of life sensors and to check that it's really a live finger and that you haven't like hacked your friend's finger off or anything like that.
[26:28.270 --> 26:33.490]  So testing whether people are live or not is quite interesting and maybe testing if they're intelligent is a nice way to do that.
[26:34.070 --> 26:36.410]  This is, I think, quite a cute Capture.
[26:38.110 --> 26:45.150]  It's quite difficult to do visual recognition with photos of things.
[26:46.470 --> 26:48.970]  Capture as a concept is not very strong.
[26:50.030 --> 26:52.170]  with the letter ones that we have.
[26:53.110 --> 27:03.150]  Very, very easy to, you know, write a few lines of pearl to be Capture stuff just by doing optical character recognition just like your scanner would.
[27:04.490 --> 27:06.650]  This Capture, however, is quite cool.
[27:06.890 --> 27:12.350]  So you have photos of a bunch of animals and you have to click on the animals that it asks for.
[27:12.510 --> 27:16.710]  So it might say, you might have like kittens and puppies and you have to click on the kittens.
[27:18.250 --> 27:21.510]  And that's relatively difficult for computer programs to do.
[27:23.610 --> 27:25.230]  This is, this is a...
[27:25.230 --> 27:38.230]  This really, really does tie into Turing and like the concept of intelligence because anyone who knows about artificial intelligence will know that there are a whole bunch of problems that look easy or look kind of doable and really aren't.
[27:40.270 --> 27:41.750]  Visual recognition is one of them.
[27:41.850 --> 27:43.810]  Speech recognition is also one of them.
[27:44.890 --> 27:48.010]  Speech recognition is really, really difficult to do well.
[27:48.250 --> 27:49.250]  It's really, really, really difficult.
[27:49.530 --> 27:52.190]  And we're not really sure why humans can do it so well.
[27:52.750 --> 28:01.330]  And again, with visual recognition, we're not really sure why it's, you know, we can instantly tell the difference between a fox and a panda.
[28:01.550 --> 28:07.490]  But computer programs really struggle because they both have like eyes and noses and other cool things that animals have.
[28:13.010 --> 28:20.330]  So Turing was at Cambridge, King's College doing math research and then World War II broke out.
[28:20.990 --> 28:26.030]  And prior to World War II, he had spent a bit of time at a place called Bletchley Park.
[28:26.230 --> 28:28.550]  He'd been visiting there for workshops and stuff.
[28:31.010 --> 28:39.470]  Bletchley Park was the government code and cipher school, which is a bit like the NSA in the U.S.
[28:40.470 --> 28:50.230]  Bletchley Park, the government code and cipher school became GCHQ, which is the government communications headquarters, which is, yeah, our equivalent of the NSA.
[28:52.010 --> 28:55.250]  So you're all familiar with like NSA and GCHQ and stuff, yeah.
[28:55.990 --> 29:10.210]  Like in the U.S., you have FBI that allegedly does security, CIA that kills people in other countries, and NSA that like feeds them both information and kind of argues about whose information it is.
[29:10.530 --> 29:11.970]  In England, we have GCHQ.
[29:13.750 --> 29:16.610]  GCHQ is like quite good at being secretive.
[29:17.990 --> 29:20.850]  Some of you may have heard of like things like public key encryption.
[29:21.770 --> 29:29.490]  Public key encryption was invented at GCHQ way before like Diffie-Hellman key exchange and all that kind of stuff.
[29:30.130 --> 29:32.830]  Well, at least a few years before and kept quiet.
[29:33.210 --> 29:36.830]  It was only a few years ago that it sort of became public.
[29:38.010 --> 29:39.710]  GCHQ is very, very secretive.
[29:39.890 --> 29:46.830]  In England, secrecy really is a key thing with certain government bodies, military and security ones.
[29:48.250 --> 29:56.410]  So a lot of the old government code and cipher school stuff relating to Turing still is kept quiet.
[29:57.130 --> 29:59.130]  Bletchley Park, quite a nice place to hang out.
[30:00.490 --> 30:03.590]  A whole bunch of people that we would really recognise as hackers.
[30:03.830 --> 30:05.490]  You know, typical hacker traits.
[30:05.690 --> 30:09.210]  The way that they solve problems related to security.
[30:09.210 --> 30:14.310]  Just a big group of people in a room passing the problem around to everyone.
[30:15.130 --> 30:17.190]  Having discussions, trying to...
[30:17.190 --> 30:19.290]  Not having like set ways to approach stuff.
[30:20.550 --> 30:28.890]  So if you look into like history of Bletchley Park and what went on there, you really see that in World War II, it's what we would consider hackers.
[30:30.190 --> 30:42.770]  Controlled by the military, but there was this sort of unwritten rule that the civilian staff people like Alan Turing and the other code breakers were given a free reign, really.
[30:43.030 --> 30:44.090]  They didn't wear uniform.
[30:44.270 --> 30:45.210]  They didn't respect rank.
[30:45.750 --> 30:46.810]  They were all equal.
[30:46.810 --> 30:48.790]  They were all just a random mixture of people.
[30:53.080 --> 31:03.780]  This was where Turing spent much of World War II in one of the sort of huts in this lovely grounds of this big stately home.
[31:05.480 --> 31:17.220]  Turing spent his days there working on security problems, working on in particular how to break codes, but also how to make some security algorithms as well, which I'll talk about a bit later on.
[31:19.300 --> 31:24.560]  The really key thing that Bletchley Park did was break the German Enigma code.
[31:26.660 --> 31:30.000]  There's quite a lot of controversy around the Enigma.
[31:30.960 --> 31:33.080]  It's not well-founded, really.
[31:33.440 --> 31:40.000]  The controversy is about whether the Polish actually broke all the Enigma first.
[31:41.640 --> 31:46.680]  The Enigma machine was an electromechanical enciphering system.
[31:47.840 --> 31:49.780]  So you put in your message.
[31:50.600 --> 31:52.440]  It does some number crunching.
[31:53.480 --> 31:54.640]  Electricity flows around.
[31:54.940 --> 31:55.800]  Things move.
[31:55.920 --> 31:56.660]  It makes a sound.
[31:56.980 --> 31:57.760]  Lights light up.
[31:57.900 --> 32:00.320]  And you have security.
[32:02.820 --> 32:05.300]  The Enigma was needed because...
[32:06.040 --> 32:08.740]  In World War I, codes were rubbish.
[32:09.040 --> 32:15.200]  I mean, it was just people writing stuff on bits of paper and, like, jumbling up letters and stuff.
[32:15.420 --> 32:16.080]  It was really, really poor.
[32:16.920 --> 32:23.020]  In the 30s, the idea of the one-time pad encryption came up.
[32:23.180 --> 32:25.580]  Everyone knows what one-time pad encryption is.
[32:26.180 --> 32:28.500]  And that's all of you again.
[32:28.500 --> 32:28.900]  Excellent.
[32:30.360 --> 32:33.960]  One-time pad encryption is theoretically...
[32:35.040 --> 32:37.140]  It's mathematically 100% secure.
[32:37.540 --> 32:39.780]  You have something you want to encode.
[32:39.900 --> 32:44.690]  And you have, essentially, a password, the same length as what you want to encode.
[32:44.880 --> 32:46.100]  And you mix them together.
[32:46.430 --> 32:48.450]  The password is completely randomly generated.
[32:48.880 --> 32:50.100]  That encodes it.
[32:50.240 --> 32:51.800]  You have to have the password to get it out.
[32:52.600 --> 32:54.480]  And then you throw away the password.
[32:54.600 --> 32:56.500]  So you use it once, hence the term one-time pad.
[32:56.500 --> 33:01.260]  Has anyone here broken systems using one-time pad encryption?
[33:01.760 --> 33:03.260]  Probably some of you have.
[33:04.480 --> 33:07.950]  One-time pad encryption is mathematically impossible to break.
[33:08.260 --> 33:15.220]  And yet, it's not massively difficult to break encryption systems using one-time pads.
[33:15.760 --> 33:16.900]  Why is that?
[33:17.260 --> 33:27.960]  Well, if it's mathematically impossible to break one-time pad encryption, Then to break a system using one-time pads can only mean that it's not using them properly.
[33:28.580 --> 33:31.930]  So one-time pads are sometimes used for, like, network security protocols.
[33:33.240 --> 33:38.820]  And they're generally not very good because they reuse the pads, so it's not one-time.
[33:39.060 --> 33:44.380]  And the random algorithms they use to generate are not very random.
[33:44.640 --> 33:46.660]  You know, the seeding isn't very good on them.
[33:46.660 --> 33:54.360]  So it's not massively difficult to break certain network encryption systems using one-time pads.
[33:54.580 --> 34:07.500]  And a British hacker, John Wignall, has been doing some work on this in the U.K., looking at things like when the messages are too short or too long and you get, like, padding.
[34:07.760 --> 34:14.160]  You, like, pad out the messages with zeros, and then you've got, like, known ciphertext, which is the real enemy of encryption.
[34:15.240 --> 34:21.910]  So the Enigma was needed, really, as it was really important to have a practical system of encryption.
[34:22.200 --> 34:31.950]  So the Enigma was way stronger than, you know, someone with a bit of paper and a pen writing a load of nonsense and jumbling it up.
[34:32.630 --> 34:36.830]  But obviously not strong-strong like one-time pad encryption.
[34:36.830 --> 34:39.330]  But it was massively popular.
[34:39.600 --> 34:43.870]  It was a commercial system sold throughout Germany in the under-30s.
[34:44.000 --> 34:46.950]  The German military weren't interested in it in the beginning.
[34:49.160 --> 34:58.370]  People became really interested in encryption just before World War II, when it was, like, discovered how easily the codes had been broken from World War I.
[34:59.830 --> 35:02.160]  In World War I, radio was really popular.
[35:02.160 --> 35:05.330]  And with radio, you really do need to be thinking about security a lot.
[35:07.600 --> 35:13.540]  The key to how the Enigma works is, like, these rotors that are in the sort of centre of the machine.
[35:15.100 --> 35:21.390]  So with Enigma, you've got a box, you've got a keyboard, and you've got some lights with letters beside them.
[35:21.600 --> 35:28.200]  And essentially, you want to be able to press a key and light up pretty much a random light here.
[35:29.980 --> 35:36.760]  Encryption is really the process of taking information and making it look random, kind of removing all the patterns from it.
[35:38.480 --> 35:46.980]  The way the Enigma did this was that when you pressed a button on the keyboard, the electrical circuit went through a bunch of rotors.
[35:47.600 --> 35:48.870]  I've got a better picture.
[35:51.890 --> 36:01.460]  You'd press, for example, A, and an electrical circuit was formed through these rotors, and G would light up.
[36:03.370 --> 36:08.060]  It wouldn't really work if it was just a bunch of wires or just something on a printed circuit board.
[36:08.260 --> 36:15.370]  But because they were rotors, as you're pressing keys, the rotors are going round, so the circuits are changing.
[36:15.520 --> 36:20.200]  So if you press A again later on in the message, you wouldn't necessarily get a G.
[36:20.330 --> 36:21.460]  You might get a C, for example.
[36:23.160 --> 36:27.960]  So you can imagine typing away and all these lights lighting up, and it looks pretty random.
[36:31.040 --> 36:46.960]  Because the electrical circuit went through the rotors one way and then came back through the rotors another way with this reflector, it meant that the encryption was sort of symmetric in the way that if someone else had the Enigma machine and it was set up the same way as yours,
[36:47.830 --> 36:54.540]  they could type in the code and get out the plain text, which was quite nice.
[36:54.620 --> 36:57.680]  So you didn't need to have, like, an encryption and decryption mode.
[36:59.540 --> 37:02.020]  The Enigma is really quite interesting.
[37:02.160 --> 37:05.160]  It's really worth looking into how it works.
[37:06.460 --> 37:13.310]  When you set up the Enigma, you've got this box, and it's got a whole lot of settings, a whole lot of things you can change.
[37:13.660 --> 37:18.980]  And you change them, and that essentially makes a configuration, just like a Turing machine's configuration.
[37:19.830 --> 37:22.100]  And in particular, we've got five things you can change.
[37:23.060 --> 37:32.080]  So you've got these rotors, and the main military Enigma machine had three rotors, and you've got a choice of five that you can put in.
[37:33.260 --> 37:34.580]  So that's quite a few combinations.
[37:35.930 --> 37:41.350]  I said that the rotors go round while you're typing your message.
[37:41.540 --> 37:51.890]  Now, the first rotor goes round quite quickly, and then every kind of once or twice it goes round, the next rotor will move, and then when that goes around once or twice, the next rotor will move.
[37:52.950 --> 37:58.450]  There was, like, a ring inside the rotor that dictated at what point it would go round.
[37:59.950 --> 38:01.910]  They're like these kind of notched rings.
[38:03.180 --> 38:04.350]  We've got three rotors.
[38:04.540 --> 38:06.100]  We can put them in different orders.
[38:06.310 --> 38:07.870]  So that's, like, another six combinations.
[38:09.080 --> 38:11.520]  We've got a plug board on the front of the Enigma.
[38:11.700 --> 38:16.000]  If we jump back to the picture, you can kind of see it.
[38:17.390 --> 38:27.700]  Right in the front of the picture, below the keyboard, you can see a whole bunch of pairs of sockets, and we've got some, like, patch leads, essentially, so we can cross over some letters.
[38:29.310 --> 38:32.330]  That makes the Enigma really difficult to break.
[38:34.000 --> 38:38.120]  Adding the plug board was made a much, much bigger...
[38:39.060 --> 38:45.260]  It increased the, sort of, number of configurations far more than adding more rotors would.
[38:45.850 --> 38:47.370]  So that's quite an interesting thing.
[38:49.950 --> 38:54.540]  Then the final thing you do is set the starting positions for those rotors.
[38:54.540 --> 38:59.660]  So those rotors have got the alphabet around the edge, and you can set the starting position.
[39:00.140 --> 39:05.480]  So generally, steps one to four would probably be, like, what we'd maybe call a day key.
[39:06.680 --> 39:09.890]  Essentially, the configuration of the Enigma is the password.
[39:10.140 --> 39:15.060]  All you need is an Enigma machine in the same configuration to decode the stuff.
[39:15.200 --> 39:20.500]  So the configuration acts as a password with billions of combinations.
[39:22.480 --> 39:24.830]  So the first four would be, like, the day code.
[39:24.960 --> 39:32.410]  And then for each message, you'd set the configuration of the initial position of these three rotors.
[39:34.460 --> 39:36.870]  So day code would be, like, in a code book.
[39:37.040 --> 39:41.980]  So you've still got this issue of distributing code books around where you're killing people.
[39:43.020 --> 39:53.410]  And then for each message, you'd start off by sending a sort of three-letter group that would say where the position of the three rotors would be.
[39:55.890 --> 39:57.700]  It was seriously difficult to break.
[39:57.870 --> 39:59.520]  And that's going back to the Polish thing.
[40:00.740 --> 40:09.310]  The Polish broke the Enigma before World War II started, which is quite a sensible thing to do, really.
[40:09.520 --> 40:11.000]  And it's a lesson we can all learn.
[40:12.240 --> 40:15.700]  You know, break technology before it's used against you.
[40:16.830 --> 40:22.850]  The Polish, you know, felt this presence, that they felt this kind of a shadow of Germany.
[40:23.060 --> 40:24.580]  They thought bad stuff might happen.
[40:25.120 --> 40:32.410]  And instead of watching TV, like we do now, they thought it might be sensible to, you know, make hay while the sun shines or whatever.
[40:34.450 --> 40:38.700]  However, the reason I don't buy into, like, this big controversy of...
[40:38.700 --> 40:55.430]  There are quite a few angry Polish people, angry that people like Turing get the credit for breaking Enigma when the Polish broke it years before and repeatedly tried to give the British Enigma machines and code books and plans of how to break it.
[40:55.500 --> 40:58.450]  And the British said, you know, we're not massively interested.
[41:01.060 --> 41:05.560]  Those are, like, fair issues, but the Enigma wasn't just one machine.
[41:05.700 --> 41:07.520]  There were whole variations of them.
[41:08.020 --> 41:10.350]  The one the Polish broke was quite simple.
[41:11.560 --> 41:16.310]  The Polish did do something really, really powerful, though, which is that they invented...
[41:17.270 --> 41:18.500]  They invented cryptography.
[41:19.160 --> 41:20.680]  They invented the idea of...
[41:20.680 --> 41:22.960]  The modern idea of how we break codes.
[41:23.330 --> 41:27.180]  In particular, what the Polish did was they had mathematicians breaking codes.
[41:27.180 --> 41:35.410]  And so prior to that, you just get a bunch of your mates around your house, really, and break some codes.
[41:35.450 --> 41:36.450]  You just get random people.
[41:36.890 --> 41:38.450]  In particular, you get linguists.
[41:38.660 --> 41:40.740]  Everyone thought, like, yeah, this is a language issue.
[41:40.870 --> 41:41.830]  We should get loads of linguists.
[41:43.430 --> 41:47.060]  The Polish thought, no, maybe maths is what we need now.
[41:48.410 --> 42:00.910]  So that was something that the British did copy, and I think that's really, really important, that people breaking Enigma or, like, Turing and people hand-picked from Cambridge and Oxford University, and they were picked from the maths departments, mainly.
[42:01.160 --> 42:06.180]  There were, like, linguists, and there were random people as well.
[42:06.310 --> 42:16.780]  One of the things Bletchley Park did was they set, like, a crossword competition in the Times and said, if you can break this crossword in, like, 18 minutes, then send us your name and address.
[42:17.180 --> 42:24.000]  Little did those people know that they'd be joining Bletchley Park, and most of them did.
[42:24.160 --> 42:32.000]  They went to Bletchley Park and did some more crossword competitions and got involved and remained there throughout the war.
[42:33.180 --> 42:36.040]  The way the Enigma was broken was...
[42:36.040 --> 42:40.200]  I mean, a lot of the ideas, we use them now for code-breaking.
[42:40.810 --> 42:43.850]  Known plain text was a really good thing.
[42:46.460 --> 42:47.980]  Again, you can...
[42:47.980 --> 42:53.200]  If you're sensible with a war or any situation, you can force plain text.
[42:54.040 --> 42:56.100]  And a good way to do that is killing people.
[42:56.310 --> 43:05.120]  So the British had this lovely idea that if they dropped bombs in certain places, bombed certain ships, they knew the grid references.
[43:05.330 --> 43:12.740]  They knew the coordinates of where those ships were, and then in the radio traffic in the next hour or so, that would be transmitted.
[43:12.740 --> 43:15.980]  So they've got something that they know what's in the message.
[43:18.890 --> 43:20.460]  People are slack as well.
[43:21.980 --> 43:25.020]  Some of the German military were a bit slack, really.
[43:25.390 --> 43:32.180]  They do things like use their girlfriend's initials as the initial rotor settings.
[43:33.640 --> 43:38.720]  Or they might transmit the weather forecast at a set time during the day in a set format.
[43:40.180 --> 43:42.200]  The Navy weren't slack at all.
[43:43.100 --> 43:46.440]  Breaking the naval enigma was the really difficult thing.
[43:47.960 --> 43:50.960]  They just enforced the rules really rigidly.
[43:51.480 --> 43:52.460]  No girlfriend's initials.
[43:52.500 --> 43:54.380]  Maybe the people in the German Navy didn't have girlfriends.
[43:54.540 --> 43:54.680]  I don't know.
[43:55.360 --> 43:58.160]  But there was no, like, girlfriend initials or anything like that.
[43:58.240 --> 44:00.320]  There was no fixed weather forecasts.
[44:01.320 --> 44:04.100]  So getting a known plain text was quite difficult.
[44:04.100 --> 44:17.840]  The main way the name was broken was that you've got these rotors, you've got this configuration, and you've got essentially pretty random text coming out, what looks like pretty random text.
[44:20.640 --> 44:25.000]  But within that text, it is really a fingerprint of how the machine is set up.
[44:25.180 --> 44:34.460]  And Turing worked out ways that we could, like, work out these fingerprints from these configurations and, like, have catalogues of fingerprints.
[44:34.780 --> 44:42.280]  And, you know, fingerprinting's something that people use in computer security all the time in, like, TCP stack fingerprinting and stuff like that.
[44:44.660 --> 44:56.960]  The fingerprints, like, manifest in themselves as these chains of letters where you're typing a message and maybe the letter E occurs quite a lot and it's encoded into various different things.
[44:57.080 --> 45:06.740]  And as the wheels go around full rotations, you get, like, these patterns coming up that were termed chains.
[45:07.100 --> 45:15.580]  To find the chains, they used an idea that the Polish had come up with these big machines called bombs, which I have courtesy of Wikipedia.
[45:15.900 --> 45:17.220]  A lovely picture of a bomb here.
[45:19.400 --> 45:23.580]  Bombs are essentially a whole bunch of Enigma machines all stuck together
[45:26.730 --> 45:28.120]  and crunching through.
[45:28.120 --> 45:39.880]  so you'd put in some cipher text and the bomb would essentially try and decode it in emulating lots of different configurations.
[45:40.240 --> 45:58.580]  Now, if you had started with just these bombs and you had essentially done a brute force attack on the Enigma, no way, you know, like with most cryptographic systems, it would be like take longer than the life of the universe, those kind of magnitudes of time to break it.
[45:58.980 --> 46:11.520]  So, the key in breaking the Enigma was reducing the number of combinations, you know, discarding things by looking at these patterns, these patterns that negated certain configurations of the machine.
[46:11.680 --> 46:14.900]  You're like casting out these configurations as much as possible.
[46:16.920 --> 46:21.460]  I'll skip Bell Labs because it's about America and we want to hear about Britain instead.
[46:24.100 --> 46:26.700]  the computer was not invented by Thomas Edison.
[46:27.200 --> 46:30.460]  I know in America we think everything was Thomas Edison.
[46:31.100 --> 46:32.820]  He didn't invent anything, come on.
[46:34.080 --> 46:36.820]  Most things in the world, bizarrely, were invented in Scotland.
[46:38.420 --> 46:42.680]  If you look at the history of invention, pretty much everything came from Scotland.
[46:42.840 --> 46:46.300]  Color photography, light bulb, first power of flight was from Scotland.
[46:46.560 --> 46:50.740]  I don't particularly like Scotland, but it's a fact that I can't ignore.
[46:51.460 --> 46:54.200]  But certainly Edison didn't didn't invent shit.
[46:56.020 --> 47:01.980]  Turing was like working on a plan for one of the first computers called the ACE.
[47:02.500 --> 47:03.460]  It's quite a cool acronym.
[47:04.600 --> 47:08.660]  And he worked on the ACE and he also went on to work on the Manchester Mark I.
[47:09.040 --> 47:19.180]  These are two really influential, important computers in Britain that sort of dictated how computers would be designed and built and how memory and stuff would work.
[47:19.520 --> 47:20.960]  So, worth looking into.
[47:24.500 --> 47:31.520]  Turing was an open homosexual throughout his life and he was persecuted.
[47:32.340 --> 47:34.300]  This is a quote from the House of Lords.
[47:34.820 --> 47:37.100]  There are the hunchback, the blind, and the dumb.
[47:38.080 --> 47:42.960]  But of all the dreadful abnormalities, surely abnormal sexual instincts must be one of the worst.
[47:44.860 --> 47:47.200]  Homosexuals were really hated in England.
[47:47.820 --> 47:53.760]  just like lots of people are hating in England and just like today, England's full of hate like many countries in our world.
[47:57.100 --> 47:59.560]  Turing was arrested for homosexuality.
[47:59.560 --> 48:02.940]  He was actually arrested after reporting a break-in in his house.
[48:04.900 --> 48:06.940]  Probably a friend of one of his...
[48:06.940 --> 48:14.540]  or an associate of one of his lovers broke into his house to nick some trousers and, I don't know, the plants to the English machine or something.
[48:15.640 --> 48:31.040]  And Turing was charged with gross indecency and because England is such a lovely progressive country, he could have gone to prison or, this is 1952, he could take what was essentially chemical castration.
[48:31.900 --> 48:39.240]  Now, in the 1950s in the U.S., like, the 15 or 16 states had physical castration was like the punishment for being a homosexual.
[48:40.460 --> 48:43.960]  but in progressive England we had some chemicals to do it.
[48:44.480 --> 48:51.700]  You essentially, like, take hormone treatment and be pumped through, like, estrogen and have stuff to suppress testosterone and stuff like that.
[48:52.880 --> 48:56.360]  A kind of consequence of this was Turing turned into a woman...
[48:56.360 --> 48:58.960]  I mean, sort of started turning into a woman.
[48:59.360 --> 49:05.320]  Women are great but if you don't want to be one, it's not cool to, like, be forced to become one.
[49:06.180 --> 49:07.520]  It's just not nice.
[49:12.000 --> 49:13.780]  Something courtesy of Google Image Search.
[49:15.020 --> 49:17.240]  There's a lot of controversy about Turing's death.
[49:19.200 --> 49:22.260]  He died, like, a couple of years after the trial.
[49:23.100 --> 49:26.780]  So, sentenced to, like, 12 months of becoming a woman.
[49:27.840 --> 49:32.460]  Then, a year later, he possibly committed suicide.
[49:32.780 --> 49:34.180]  He was found dead in his house.
[49:35.100 --> 49:40.420]  Official verdict was suicide by cyanide poisoning.
[49:44.420 --> 49:49.540]  I'm not massively interested in whether he sort of jumped or was pushed.
[49:50.020 --> 49:51.000]  I don't think...
[49:51.000 --> 49:55.020]  Either way, you know, I feel he was murdered by the state.
[49:55.460 --> 50:07.160]  You know, whether he was, like, just persecuted as a homosexual and that drove him to kill himself or whether he was actually assassinated for use of a clinical term.
[50:07.360 --> 50:10.180]  A whole bunch of points about the death that were a bit strange.
[50:10.640 --> 50:14.620]  This apple that everyone assumed was poisoned was never tested or anything.
[50:17.060 --> 50:19.460]  So, you know, do look into the death.
[50:19.720 --> 50:20.580]  Read about it on Wikipedia.
[50:20.900 --> 50:21.600]  Read the Hodges book.
[50:22.840 --> 50:23.320]  And...
[50:28.710 --> 50:34.310]  When you look at people like Turing, who were, like, obviously exceptionally intelligent and did a lot of really cool stuff.
[50:37.270 --> 50:40.190]  You have to ask, like, what can you learn from them?
[50:40.590 --> 50:41.030]  And...
[50:42.070 --> 50:48.870]  In a lecture on Japanese garden design, I saw this really nice quote from Matsuo Basho, who is a haiku writer.
[50:49.150 --> 50:51.210]  Do not seek to emulate the old masters.
[50:51.430 --> 50:52.230]  Seek what they sought.
[50:52.890 --> 51:05.910]  I think that when you look at the lives of people like Turing, you should, instead of just trying to, like, copy what they did, you know, instead of, like, running home and building an Enigma machine and, you know, building some physical Turing machines to see what happens.
[51:06.490 --> 51:14.670]  It's really nice to just try and think why he cared about this stuff, why he was interested, particularly in the mathematics.
[51:14.670 --> 51:18.650]  I know some people are a little bit scared of mathematics and there are good reasons for that.
[51:20.170 --> 51:23.930]  But it's really nice to think about big, difficult ideas a lot.
[51:26.250 --> 51:30.590]  It's just really healthy for your brain to think about really random, difficult stuff.
[51:31.410 --> 51:32.370]  so please do.
[51:35.970 --> 51:41.950]  I've been going to, like, hacker cons for the past few years and seen hundreds of talks.
[51:42.930 --> 51:47.030]  One kind of stood out head and shoulders above the rest.
[51:47.630 --> 51:55.590]  So my talk's dedicated to a guy called Appleborn who possibly is hiding in the audience right now.
[51:55.730 --> 51:56.470]  I can see him, in fact.
[51:56.690 --> 51:57.750]  So he's not dead or anything.
[51:57.970 --> 52:00.310]  It's not, like, dedicated to the memory of Jacob Appleborn.
[52:02.290 --> 52:09.690]  But rumor has it that he may be speaking today in the afternoon on track C, although I didn't see him written up there.
[52:11.290 --> 52:12.850]  This guy is an awesome speaker.
[52:13.050 --> 52:21.190]  He really sort of sets the level of what hacker cons should be about and a really, really powerful speaker.
[52:21.890 --> 52:24.170]  Please go and see him if he is talking today.
[52:25.330 --> 52:26.150]  I'm not...
[52:26.150 --> 52:27.450]  I might take, like...
[52:27.450 --> 52:28.690]  No, I'm not going to take any questions, actually.
[52:29.510 --> 52:32.990]  If you want to ask me questions, I'm here for, like, the next six days.
[52:33.290 --> 52:36.550]  But it is nice to have questions at the end of talks.
[52:36.570 --> 52:40.070]  But I really think if you're interested, come and find me at the con.
[52:40.390 --> 52:44.910]  You know, email me, post some comments on my blog.
[52:46.370 --> 52:48.870]  Unless there's, like, like, one...
[52:48.870 --> 52:49.370]  Maybe one...
[52:49.370 --> 52:51.530]  Has anyone got a really burning question about Turing?
[52:53.670 --> 52:54.530]  That's all of you.
[52:56.070 --> 52:58.170]  So, you know, come and hunt me out.
[52:58.350 --> 53:12.470]  And if there's sufficient interest, then I'll sign up for a talk on Track C probably on the last day if people want me to go into a lot more detail about maybe the Ingmar machine, the cryptography, or if you're interested in, like, artificial intelligence and that kind of thing,
[53:12.470 --> 53:14.130]  we could maybe have more of a discussion.
[53:14.130 --> 53:22.630]  so if people come and are interested, come and find me and look out on the listing for Track C.
[53:23.050 --> 53:26.690]  Track C is, like, around the corner and I'll sign up.
[53:27.090 --> 53:28.690]  So, that's it.
[53:28.790 --> 53:30.850]  Thank you ever so much for an hour of your lives.
[53:31.170 --> 53:31.470]  Thank you.