[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.78,0:00:04.06,Default,,0000,0000,0000,,I'm in the business\Nof safeguarding secrets,
Dialogue: 0,0:00:04.08,0:00:06.25,Default,,0000,0000,0000,,and this includes your secrets.
Dialogue: 0,0:00:07.21,0:00:09.34,Default,,0000,0000,0000,,Cryptographers are\Nthe first line of defense
Dialogue: 0,0:00:09.36,0:00:12.95,Default,,0000,0000,0000,,in an ongoing war that's been\Nraging for centuries:
Dialogue: 0,0:00:12.97,0:00:15.23,Default,,0000,0000,0000,,a war between code makers
Dialogue: 0,0:00:15.26,0:00:16.51,Default,,0000,0000,0000,,and code breakers.
Dialogue: 0,0:00:17.03,0:00:19.12,Default,,0000,0000,0000,,And this is a war on information.
Dialogue: 0,0:00:20.23,0:00:23.71,Default,,0000,0000,0000,,The modern battlefield\Nfor information is digital.
Dialogue: 0,0:00:23.74,0:00:25.90,Default,,0000,0000,0000,,And it wages across your phones,
Dialogue: 0,0:00:25.92,0:00:27.10,Default,,0000,0000,0000,,your computers
Dialogue: 0,0:00:27.12,0:00:28.29,Default,,0000,0000,0000,,and the internet.
Dialogue: 0,0:00:29.30,0:00:34.28,Default,,0000,0000,0000,,Our job is to create systems that scramble\Nyour emails and credit card numbers,
Dialogue: 0,0:00:34.30,0:00:36.56,Default,,0000,0000,0000,,your phone calls and text messages --
Dialogue: 0,0:00:36.58,0:00:38.78,Default,,0000,0000,0000,,and that includes those saucy selfies --
Dialogue: 0,0:00:38.80,0:00:40.02,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:00:40.05,0:00:42.80,Default,,0000,0000,0000,,so that all of this information\Ncan only be descrambled
Dialogue: 0,0:00:42.82,0:00:44.94,Default,,0000,0000,0000,,by the recipient that it's intended for.
Dialogue: 0,0:00:46.02,0:00:48.33,Default,,0000,0000,0000,,Now, until very recently,
Dialogue: 0,0:00:48.35,0:00:50.91,Default,,0000,0000,0000,,we thought we'd won this war for good.
Dialogue: 0,0:00:51.69,0:00:54.64,Default,,0000,0000,0000,,Right now, each of your smartphones\Nis using encryption
Dialogue: 0,0:00:54.66,0:00:58.36,Default,,0000,0000,0000,,that we thought was unbreakable\Nand that was going to remain that way.
Dialogue: 0,0:00:59.65,0:01:01.59,Default,,0000,0000,0000,,We were wrong,
Dialogue: 0,0:01:01.62,0:01:04.00,Default,,0000,0000,0000,,because quantum computers are coming,
Dialogue: 0,0:01:04.03,0:01:06.82,Default,,0000,0000,0000,,and they're going to change\Nthe game completely.
Dialogue: 0,0:01:08.44,0:01:10.90,Default,,0000,0000,0000,,Throughout history,\Ncryptography and code-breaking
Dialogue: 0,0:01:10.92,0:01:12.100,Default,,0000,0000,0000,,has always been this game\Nof cat and mouse.
Dialogue: 0,0:01:13.60,0:01:15.28,Default,,0000,0000,0000,,Back in the 1500s,
Dialogue: 0,0:01:15.30,0:01:18.48,Default,,0000,0000,0000,,Queen Mary of the Scots thought\Nshe was sending encrypted letters
Dialogue: 0,0:01:18.50,0:01:20.48,Default,,0000,0000,0000,,that only her soldiers could decipher.
Dialogue: 0,0:01:21.07,0:01:23.12,Default,,0000,0000,0000,,But Queen Elizabeth of England,
Dialogue: 0,0:01:23.14,0:01:25.54,Default,,0000,0000,0000,,she had code breakers\Nthat were all over it.
Dialogue: 0,0:01:26.12,0:01:28.12,Default,,0000,0000,0000,,They decrypted Mary's letters,
Dialogue: 0,0:01:28.14,0:01:31.32,Default,,0000,0000,0000,,saw that she was attempting\Nto assassinate Elizabeth
Dialogue: 0,0:01:31.34,0:01:33.77,Default,,0000,0000,0000,,and, subsequently,\Nthey chopped Mary's head off.
Dialogue: 0,0:01:35.73,0:01:38.08,Default,,0000,0000,0000,,A few centuries later, in World War II,
Dialogue: 0,0:01:38.99,0:01:41.87,Default,,0000,0000,0000,,the Nazis communicated\Nusing the Engima code,
Dialogue: 0,0:01:41.90,0:01:45.54,Default,,0000,0000,0000,,a much more complicated encryption scheme\Nthat they thought was unbreakable.
Dialogue: 0,0:01:46.27,0:01:48.20,Default,,0000,0000,0000,,But then good old Alan Turing,
Dialogue: 0,0:01:48.23,0:01:51.26,Default,,0000,0000,0000,,the same guy who invented\Nwhat we now call the modern computer,
Dialogue: 0,0:01:51.29,0:01:53.90,Default,,0000,0000,0000,,he built a machine and used it\Nto break Enigma.
Dialogue: 0,0:01:54.54,0:01:56.15,Default,,0000,0000,0000,,He deciphered the German messages
Dialogue: 0,0:01:56.17,0:01:58.89,Default,,0000,0000,0000,,and helped to bring Hitler\Nand his Third Reich to a halt.
Dialogue: 0,0:01:59.77,0:02:02.33,Default,,0000,0000,0000,,And so the story has gone\Nthroughout the centuries.
Dialogue: 0,0:02:02.82,0:02:05.32,Default,,0000,0000,0000,,Cryptographers improve their encryption,
Dialogue: 0,0:02:05.35,0:02:08.48,Default,,0000,0000,0000,,and then code breakers fight back\Nand they find a way to break it.
Dialogue: 0,0:02:08.97,0:02:12.36,Default,,0000,0000,0000,,This war's gone back and forth,\Nand it's been pretty neck and neck.
Dialogue: 0,0:02:13.53,0:02:16.25,Default,,0000,0000,0000,,That was until the 1970s,
Dialogue: 0,0:02:16.27,0:02:18.93,Default,,0000,0000,0000,,when some cryptographers\Nmade a huge breakthrough.
Dialogue: 0,0:02:19.78,0:02:23.34,Default,,0000,0000,0000,,They discovered an extremely\Npowerful way to do encryption
Dialogue: 0,0:02:23.37,0:02:25.12,Default,,0000,0000,0000,,called "public-key cryptography."
Dialogue: 0,0:02:25.84,0:02:30.11,Default,,0000,0000,0000,,Unlike all of the prior methods used\Nthroughout history, it doesn't require
Dialogue: 0,0:02:30.14,0:02:33.74,Default,,0000,0000,0000,,that the two parties that want to send\Neach other confidential information
Dialogue: 0,0:02:33.77,0:02:35.83,Default,,0000,0000,0000,,have exchanged the secret key beforehand.
Dialogue: 0,0:02:36.60,0:02:40.71,Default,,0000,0000,0000,,The magic of public-key cryptography\Nis that it allows us to connect securely
Dialogue: 0,0:02:40.74,0:02:42.28,Default,,0000,0000,0000,,with anyone in the world,
Dialogue: 0,0:02:43.48,0:02:46.35,Default,,0000,0000,0000,,whether we've exchanged\Ndata before or not,
Dialogue: 0,0:02:46.37,0:02:50.04,Default,,0000,0000,0000,,and to do it so fast that you and I\Ndon't even realize it's happening.
Dialogue: 0,0:02:51.00,0:02:54.24,Default,,0000,0000,0000,,Whether you're texting your mate\Nto catch up for a beer,
Dialogue: 0,0:02:54.26,0:02:58.51,Default,,0000,0000,0000,,or you're a bank that's transferring\Nbillions of dollars to another bank,
Dialogue: 0,0:02:58.53,0:03:01.58,Default,,0000,0000,0000,,modern encryption enables us\Nto send data that can be secured
Dialogue: 0,0:03:01.61,0:03:03.63,Default,,0000,0000,0000,,in a matter of milliseconds.
Dialogue: 0,0:03:05.50,0:03:08.38,Default,,0000,0000,0000,,The brilliant idea that makes\Nthis magic possible,
Dialogue: 0,0:03:08.41,0:03:10.94,Default,,0000,0000,0000,,it relies on hard mathematical problems.
Dialogue: 0,0:03:11.62,0:03:15.46,Default,,0000,0000,0000,,Cryptographers are deeply interested\Nin things that calculators can't do.
Dialogue: 0,0:03:17.25,0:03:20.65,Default,,0000,0000,0000,,For example, calculators can multiply\Nany two numbers you like,
Dialogue: 0,0:03:20.68,0:03:22.36,Default,,0000,0000,0000,,no matter how big the size.
Dialogue: 0,0:03:23.18,0:03:25.12,Default,,0000,0000,0000,,But going back the other way --
Dialogue: 0,0:03:25.14,0:03:27.36,Default,,0000,0000,0000,,starting with the product and then asking,
Dialogue: 0,0:03:27.38,0:03:29.75,Default,,0000,0000,0000,,"Which two numbers multiply\Nto give this one?" --
Dialogue: 0,0:03:29.77,0:03:32.15,Default,,0000,0000,0000,,that's actually a really hard problem.
Dialogue: 0,0:03:33.36,0:03:37.95,Default,,0000,0000,0000,,If I asked you to find which two-digit\Nnumbers multiply to give 851,
Dialogue: 0,0:03:39.05,0:03:40.24,Default,,0000,0000,0000,,even with a calculator,
Dialogue: 0,0:03:40.27,0:03:43.37,Default,,0000,0000,0000,,most people in this room would have\Na hard time finding the answer
Dialogue: 0,0:03:43.40,0:03:45.31,Default,,0000,0000,0000,,by the time I'm finished with this talk.
Dialogue: 0,0:03:45.34,0:03:47.100,Default,,0000,0000,0000,,And if I make the numbers a little larger,
Dialogue: 0,0:03:48.02,0:03:51.68,Default,,0000,0000,0000,,then there's no calculator on earth\Nthat can do this.
Dialogue: 0,0:03:51.70,0:03:54.59,Default,,0000,0000,0000,,In fact, even the world's\Nfastest supercomputer
Dialogue: 0,0:03:54.61,0:03:57.10,Default,,0000,0000,0000,,would take longer\Nthan the life age of the universe
Dialogue: 0,0:03:57.12,0:03:59.100,Default,,0000,0000,0000,,to find the two numbers\Nthat multiply to give this one.
Dialogue: 0,0:04:01.03,0:04:04.37,Default,,0000,0000,0000,,And this problem,\Ncalled "integer factorization,"
Dialogue: 0,0:04:04.39,0:04:08.02,Default,,0000,0000,0000,,is exactly what each of your smartphones\Nand laptops is using right now
Dialogue: 0,0:04:08.04,0:04:09.58,Default,,0000,0000,0000,,to keep your data secure.
Dialogue: 0,0:04:10.25,0:04:12.67,Default,,0000,0000,0000,,This is the basis of modern encryption.
Dialogue: 0,0:04:14.27,0:04:18.48,Default,,0000,0000,0000,,And the fact that all the computing power\Non the planet combined can't solve it,
Dialogue: 0,0:04:18.50,0:04:21.37,Default,,0000,0000,0000,,that's the reason we cryptographers\Nthought we'd found a way
Dialogue: 0,0:04:21.40,0:04:23.66,Default,,0000,0000,0000,,to stay ahead of the code\Nbreakers for good.
Dialogue: 0,0:04:25.13,0:04:26.78,Default,,0000,0000,0000,,Perhaps we got a little cocky
Dialogue: 0,0:04:27.90,0:04:30.25,Default,,0000,0000,0000,,because just when we thought\Nthe war was won,
Dialogue: 0,0:04:30.27,0:04:33.21,Default,,0000,0000,0000,,a bunch of 20th-century physicists\Ncame to the party,
Dialogue: 0,0:04:33.23,0:04:35.91,Default,,0000,0000,0000,,and they revealed\Nthat the laws of the universe,
Dialogue: 0,0:04:35.94,0:04:38.53,Default,,0000,0000,0000,,the same laws that modern\Ncryptography was built upon,
Dialogue: 0,0:04:39.42,0:04:41.24,Default,,0000,0000,0000,,they aren't as we thought they were.
Dialogue: 0,0:04:42.20,0:04:45.72,Default,,0000,0000,0000,,We thought that one object couldn't be\Nin two places at the same time.
Dialogue: 0,0:04:46.26,0:04:47.80,Default,,0000,0000,0000,,It's not the case.
Dialogue: 0,0:04:47.83,0:04:51.54,Default,,0000,0000,0000,,We thought nothing can possibly spin\Nclockwise and anticlockwise
Dialogue: 0,0:04:51.56,0:04:52.85,Default,,0000,0000,0000,,simultaneously.
Dialogue: 0,0:04:53.26,0:04:54.65,Default,,0000,0000,0000,,But that's incorrect.
Dialogue: 0,0:04:55.17,0:04:58.88,Default,,0000,0000,0000,,And we thought that two objects\Non opposite sides of the universe,
Dialogue: 0,0:04:58.91,0:05:01.21,Default,,0000,0000,0000,,light years away from each other,
Dialogue: 0,0:05:01.23,0:05:04.80,Default,,0000,0000,0000,,they can't possible influence\None another instantaneously.
Dialogue: 0,0:05:05.93,0:05:07.18,Default,,0000,0000,0000,,We were wrong again.
Dialogue: 0,0:05:08.40,0:05:10.61,Default,,0000,0000,0000,,And isn't that always the way\Nlife seems to go?
Dialogue: 0,0:05:10.64,0:05:14.03,Default,,0000,0000,0000,,Just when you think you've got\Neverything covered, your ducks in a row,
Dialogue: 0,0:05:14.06,0:05:15.61,Default,,0000,0000,0000,,a bunch of physicists come along
Dialogue: 0,0:05:15.64,0:05:19.33,Default,,0000,0000,0000,,and reveal that the fundamental laws\Nof the universe are completely different
Dialogue: 0,0:05:19.35,0:05:20.51,Default,,0000,0000,0000,,to what you thought?
Dialogue: 0,0:05:20.54,0:05:21.59,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:05:21.62,0:05:22.97,Default,,0000,0000,0000,,And it screws everything up.
Dialogue: 0,0:05:22.100,0:05:27.52,Default,,0000,0000,0000,,See, in the teeny tiny subatomic realm,
Dialogue: 0,0:05:27.55,0:05:30.56,Default,,0000,0000,0000,,at the level of electrons and protons,
Dialogue: 0,0:05:30.58,0:05:32.41,Default,,0000,0000,0000,,the classical laws of physics,
Dialogue: 0,0:05:32.43,0:05:34.27,Default,,0000,0000,0000,,the ones that we all know and love,
Dialogue: 0,0:05:34.29,0:05:35.53,Default,,0000,0000,0000,,they go out the window.
Dialogue: 0,0:05:36.02,0:05:38.83,Default,,0000,0000,0000,,And it's here that the laws\Nof quantum mechanics kick in.
Dialogue: 0,0:05:39.69,0:05:40.87,Default,,0000,0000,0000,,In quantum mechanics,
Dialogue: 0,0:05:40.90,0:05:45.38,Default,,0000,0000,0000,,an electron can be spinning clockwise\Nand anticlockwise at the same time,
Dialogue: 0,0:05:45.40,0:05:47.96,Default,,0000,0000,0000,,and a proton can be in two places at once.
Dialogue: 0,0:05:49.94,0:05:52.06,Default,,0000,0000,0000,,It sounds like science fiction,
Dialogue: 0,0:05:52.09,0:05:56.28,Default,,0000,0000,0000,,but that's only because\Nthe crazy quantum nature of our universe,
Dialogue: 0,0:05:56.31,0:05:57.98,Default,,0000,0000,0000,,it hides itself from us.
Dialogue: 0,0:05:58.88,0:06:02.18,Default,,0000,0000,0000,,And it stayed hidden from us\Nuntil the 20th century.
Dialogue: 0,0:06:03.49,0:06:07.26,Default,,0000,0000,0000,,But now that we've seen it,\Nthe whole world is in an arms race
Dialogue: 0,0:06:07.29,0:06:09.56,Default,,0000,0000,0000,,to try to build a quantum computer --
Dialogue: 0,0:06:10.46,0:06:14.79,Default,,0000,0000,0000,,a computer that can harness the power\Nof this weird and wacky quantum behavior.
Dialogue: 0,0:06:16.38,0:06:18.83,Default,,0000,0000,0000,,These things are so revolutionary
Dialogue: 0,0:06:18.86,0:06:20.62,Default,,0000,0000,0000,,and so powerful
Dialogue: 0,0:06:20.64,0:06:22.100,Default,,0000,0000,0000,,that they'll make today's\Nfastest supercomputer
Dialogue: 0,0:06:23.02,0:06:25.10,Default,,0000,0000,0000,,look useless in comparison.
Dialogue: 0,0:06:25.87,0:06:28.89,Default,,0000,0000,0000,,In fact, for certain problems\Nthat are of great interest to us,
Dialogue: 0,0:06:29.63,0:06:32.24,Default,,0000,0000,0000,,today's fastest supercomputer\Nis closer to an abacus
Dialogue: 0,0:06:32.27,0:06:33.94,Default,,0000,0000,0000,,than to a quantum computer.
Dialogue: 0,0:06:33.97,0:06:37.50,Default,,0000,0000,0000,,That's right, I'm talking about\Nthose little wooden things with the beads.
Dialogue: 0,0:06:38.48,0:06:42.74,Default,,0000,0000,0000,,Quantum computers can simulate\Nchemical and biological processes
Dialogue: 0,0:06:42.77,0:06:45.68,Default,,0000,0000,0000,,that are far beyond the reach\Nof our classical computers.
Dialogue: 0,0:06:46.81,0:06:52.40,Default,,0000,0000,0000,,And as such, they promise to help us solve\Nsome of our planet's biggest problems.
Dialogue: 0,0:06:53.49,0:06:55.76,Default,,0000,0000,0000,,They're going to help us\Ncombat global hunger;
Dialogue: 0,0:06:57.07,0:06:59.39,Default,,0000,0000,0000,,to tackle climate change;
Dialogue: 0,0:06:59.42,0:07:03.38,Default,,0000,0000,0000,,to find cures for diseases and pandemics\Nfor which we've so far been unsuccessful;
Dialogue: 0,0:07:04.21,0:07:07.12,Default,,0000,0000,0000,,to create superhuman\Nartificial intelligence;
Dialogue: 0,0:07:08.03,0:07:10.94,Default,,0000,0000,0000,,and perhaps even more important\Nthan all of those things,
Dialogue: 0,0:07:10.96,0:07:14.69,Default,,0000,0000,0000,,they're going to help us understand\Nthe very nature of our universe.
Dialogue: 0,0:07:16.38,0:07:18.59,Default,,0000,0000,0000,,But with this incredible potential
Dialogue: 0,0:07:19.79,0:07:21.42,Default,,0000,0000,0000,,comes an incredible risk.
Dialogue: 0,0:07:22.78,0:07:25.17,Default,,0000,0000,0000,,Remember those big numbers\NI talked about earlier?
Dialogue: 0,0:07:26.15,0:07:28.25,Default,,0000,0000,0000,,I'm not talking about 851.
Dialogue: 0,0:07:28.28,0:07:30.46,Default,,0000,0000,0000,,In fact, if anyone in here\Nhas been distracted
Dialogue: 0,0:07:30.48,0:07:31.92,Default,,0000,0000,0000,,trying to find those factors,
Dialogue: 0,0:07:31.94,0:07:35.50,Default,,0000,0000,0000,,I'm going to put you out of your misery\Nand tell you that it's 23 times 37.
Dialogue: 0,0:07:35.52,0:07:36.72,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:07:36.74,0:07:39.47,Default,,0000,0000,0000,,I'm talking about the much\Nbigger number that followed it.
Dialogue: 0,0:07:40.30,0:07:43.80,Default,,0000,0000,0000,,While today's fastest supercomputer\Ncouldn't find those factors
Dialogue: 0,0:07:43.82,0:07:46.16,Default,,0000,0000,0000,,in the life age of the universe,
Dialogue: 0,0:07:46.18,0:07:49.06,Default,,0000,0000,0000,,a quantum computer\Ncould easily factorize numbers
Dialogue: 0,0:07:49.08,0:07:50.65,Default,,0000,0000,0000,,way, way bigger than that one.
Dialogue: 0,0:07:51.88,0:07:55.29,Default,,0000,0000,0000,,Quantum computers will break\Nall of the encryption currently used
Dialogue: 0,0:07:55.32,0:07:57.29,Default,,0000,0000,0000,,to protect you and I from hackers.
Dialogue: 0,0:07:57.32,0:07:58.74,Default,,0000,0000,0000,,And they'll do it easily.
Dialogue: 0,0:08:00.54,0:08:01.87,Default,,0000,0000,0000,,Let me put it this way:
Dialogue: 0,0:08:01.90,0:08:03.67,Default,,0000,0000,0000,,if quantum computing was a spear,
Dialogue: 0,0:08:04.67,0:08:06.20,Default,,0000,0000,0000,,then modern encryption,
Dialogue: 0,0:08:06.22,0:08:09.60,Default,,0000,0000,0000,,the same unbreakable system\Nthat's protected us for decades,
Dialogue: 0,0:08:09.62,0:08:12.28,Default,,0000,0000,0000,,it would be like a shield\Nmade of tissue paper.
Dialogue: 0,0:08:13.58,0:08:17.57,Default,,0000,0000,0000,,Anyone with access to a quantum computer\Nwill have the master key
Dialogue: 0,0:08:17.59,0:08:20.28,Default,,0000,0000,0000,,to unlock anything they like\Nin our digital world.
Dialogue: 0,0:08:21.29,0:08:23.10,Default,,0000,0000,0000,,They could steal money from banks
Dialogue: 0,0:08:23.13,0:08:24.56,Default,,0000,0000,0000,,and control economies.
Dialogue: 0,0:08:25.30,0:08:28.20,Default,,0000,0000,0000,,They could power off hospitals\Nor launch nukes,
Dialogue: 0,0:08:28.22,0:08:31.56,Default,,0000,0000,0000,,or they could just sit back\Nand watch all of us on our webcams
Dialogue: 0,0:08:31.58,0:08:33.94,Default,,0000,0000,0000,,without any of us knowing\Nthat this is happening.
Dialogue: 0,0:08:37.31,0:08:41.27,Default,,0000,0000,0000,,Now, the fundamental unit of information\Non all of the computers we're used to,
Dialogue: 0,0:08:41.30,0:08:42.80,Default,,0000,0000,0000,,like this one,
Dialogue: 0,0:08:42.83,0:08:44.17,Default,,0000,0000,0000,,it's called a "bit."
Dialogue: 0,0:08:44.65,0:08:46.87,Default,,0000,0000,0000,,A single bit can be one of two states:
Dialogue: 0,0:08:46.90,0:08:49.16,Default,,0000,0000,0000,,it can be a zero or it can be a one.
Dialogue: 0,0:08:50.16,0:08:52.98,Default,,0000,0000,0000,,When I FaceTime my mum\Nfrom the other side of the world --
Dialogue: 0,0:08:53.75,0:08:56.23,Default,,0000,0000,0000,,and she's going to kill\Nme for having this slide --
Dialogue: 0,0:08:56.26,0:08:57.65,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:08:57.68,0:09:01.41,Default,,0000,0000,0000,,we're actually just sending each other\Nlong sequences of zeroes and ones
Dialogue: 0,0:09:01.43,0:09:04.64,Default,,0000,0000,0000,,that bounce from computer to computer,\Nfrom satellite to satellite,
Dialogue: 0,0:09:04.66,0:09:06.80,Default,,0000,0000,0000,,transmitting our data at a rapid pace.
Dialogue: 0,0:09:06.83,0:09:08.83,Default,,0000,0000,0000,,Bits are certainly very useful.
Dialogue: 0,0:09:08.86,0:09:11.55,Default,,0000,0000,0000,,In fact, anything\Nwe currently do with technology
Dialogue: 0,0:09:11.58,0:09:13.64,Default,,0000,0000,0000,,is indebted to the usefulness of bits.
Dialogue: 0,0:09:14.84,0:09:16.23,Default,,0000,0000,0000,,But we're starting to realize
Dialogue: 0,0:09:16.25,0:09:20.77,Default,,0000,0000,0000,,that bits are really poor at simulating\Ncomplex molecules and particles.
Dialogue: 0,0:09:21.39,0:09:23.37,Default,,0000,0000,0000,,And this is because, in some sense,
Dialogue: 0,0:09:23.39,0:09:26.48,Default,,0000,0000,0000,,subatomic processes can be doing\Ntwo or more opposing things
Dialogue: 0,0:09:26.50,0:09:27.69,Default,,0000,0000,0000,,at the same time
Dialogue: 0,0:09:27.72,0:09:30.70,Default,,0000,0000,0000,,as they follow these bizarre rules\Nof quantum mechanics.
Dialogue: 0,0:09:31.23,0:09:32.78,Default,,0000,0000,0000,,So, late last century,
Dialogue: 0,0:09:32.80,0:09:36.02,Default,,0000,0000,0000,,some really brainy physicists\Nhad this ingenious idea:
Dialogue: 0,0:09:36.04,0:09:38.04,Default,,0000,0000,0000,,to instead build computers\Nthat are founded
Dialogue: 0,0:09:38.07,0:09:40.16,Default,,0000,0000,0000,,on the principles of quantum mechanics.
Dialogue: 0,0:09:42.56,0:09:45.78,Default,,0000,0000,0000,,Now, the fundamental unit of information\Nof a quantum computer,
Dialogue: 0,0:09:45.80,0:09:47.05,Default,,0000,0000,0000,,it's called a "qubit."
Dialogue: 0,0:09:47.58,0:09:49.38,Default,,0000,0000,0000,,It stands for "quantum bit."
Dialogue: 0,0:09:50.99,0:09:54.24,Default,,0000,0000,0000,,Instead of having just two states,\Nlike zero or one,
Dialogue: 0,0:09:54.27,0:09:57.16,Default,,0000,0000,0000,,a qubit can be an infinite\Nnumber of states.
Dialogue: 0,0:09:57.85,0:10:01.52,Default,,0000,0000,0000,,And this corresponds to it being\Nsome combination of both zero and one
Dialogue: 0,0:10:01.54,0:10:03.33,Default,,0000,0000,0000,,at the same time,
Dialogue: 0,0:10:03.35,0:10:05.54,Default,,0000,0000,0000,,a phenomenon that we call "superposition."
Dialogue: 0,0:10:06.57,0:10:09.27,Default,,0000,0000,0000,,And when we have two qubits\Nin superposition,
Dialogue: 0,0:10:09.30,0:10:11.68,Default,,0000,0000,0000,,we're actually working across\Nall four combinations
Dialogue: 0,0:10:11.70,0:10:14.21,Default,,0000,0000,0000,,of zero-zero, zero-one,\None-zero and one-one.
Dialogue: 0,0:10:14.94,0:10:16.29,Default,,0000,0000,0000,,With three qubits,
Dialogue: 0,0:10:16.31,0:10:19.55,Default,,0000,0000,0000,,we're working in superposition\Nacross eight combinations,
Dialogue: 0,0:10:19.58,0:10:20.73,Default,,0000,0000,0000,,and so on.
Dialogue: 0,0:10:21.29,0:10:25.24,Default,,0000,0000,0000,,Each time we add a single qubit,\Nwe double the number of combinations
Dialogue: 0,0:10:25.27,0:10:28.87,Default,,0000,0000,0000,,that we can work with in superposition
Dialogue: 0,0:10:28.89,0:10:30.07,Default,,0000,0000,0000,,at the same time.
Dialogue: 0,0:10:31.00,0:10:33.63,Default,,0000,0000,0000,,And so when we scale up\Nto work with many qubits,
Dialogue: 0,0:10:33.66,0:10:37.28,Default,,0000,0000,0000,,we can work with an exponential\Nnumber of combinations
Dialogue: 0,0:10:37.30,0:10:38.62,Default,,0000,0000,0000,,at the same time.
Dialogue: 0,0:10:39.44,0:10:43.08,Default,,0000,0000,0000,,And this just hints at where the power\Nof quantum computing is coming from.
Dialogue: 0,0:10:44.96,0:10:46.29,Default,,0000,0000,0000,,Now, in modern encryption,
Dialogue: 0,0:10:47.43,0:10:51.36,Default,,0000,0000,0000,,our secret keys, like the two factors\Nof that larger number,
Dialogue: 0,0:10:51.38,0:10:53.66,Default,,0000,0000,0000,,they're just long sequences\Nof zeroes and ones.
Dialogue: 0,0:10:54.54,0:10:55.78,Default,,0000,0000,0000,,To find them,
Dialogue: 0,0:10:55.81,0:11:00.25,Default,,0000,0000,0000,,a classical computer must go through\Nevery single combination,
Dialogue: 0,0:11:00.28,0:11:01.43,Default,,0000,0000,0000,,one after the other,
Dialogue: 0,0:11:01.45,0:11:04.53,Default,,0000,0000,0000,,until it finds the one that works\Nand breaks our encryption.
Dialogue: 0,0:11:06.19,0:11:07.74,Default,,0000,0000,0000,,But on a quantum computer,
Dialogue: 0,0:11:08.78,0:11:11.97,Default,,0000,0000,0000,,with enough qubits in superposition,
Dialogue: 0,0:11:13.00,0:11:17.33,Default,,0000,0000,0000,,information can be extracted\Nfrom all combinations at the same time.
Dialogue: 0,0:11:18.91,0:11:20.17,Default,,0000,0000,0000,,In very few steps,
Dialogue: 0,0:11:20.19,0:11:24.16,Default,,0000,0000,0000,,a quantum computer can brush aside\Nall of the incorrect combinations,
Dialogue: 0,0:11:24.19,0:11:25.60,Default,,0000,0000,0000,,home in on the correct one
Dialogue: 0,0:11:25.62,0:11:27.69,Default,,0000,0000,0000,,and then unlock our treasured secrets.
Dialogue: 0,0:11:32.22,0:11:34.78,Default,,0000,0000,0000,,Now, at the crazy quantum level,
Dialogue: 0,0:11:35.90,0:11:38.52,Default,,0000,0000,0000,,something truly incredible\Nis happening here.
Dialogue: 0,0:11:40.62,0:11:44.30,Default,,0000,0000,0000,,The conventional wisdom\Nheld by many leading physicists --
Dialogue: 0,0:11:44.32,0:11:46.94,Default,,0000,0000,0000,,and you've got to stay\Nwith me on this one --
Dialogue: 0,0:11:46.97,0:11:51.39,Default,,0000,0000,0000,,is that each combination is actually\Nexamined by its very own quantum computer
Dialogue: 0,0:11:51.41,0:11:53.96,Default,,0000,0000,0000,,inside its very own parallel universe.
Dialogue: 0,0:11:55.30,0:11:59.20,Default,,0000,0000,0000,,Each of these combinations,\Nthey add up like waves in a pool of water.
Dialogue: 0,0:12:00.08,0:12:02.07,Default,,0000,0000,0000,,The combinations that are wrong,
Dialogue: 0,0:12:02.10,0:12:04.07,Default,,0000,0000,0000,,they cancel each other out,
Dialogue: 0,0:12:04.10,0:12:05.86,Default,,0000,0000,0000,,and the combinations that are right,
Dialogue: 0,0:12:05.88,0:12:07.74,Default,,0000,0000,0000,,they reinforce and amplify each other.
Dialogue: 0,0:12:08.24,0:12:10.91,Default,,0000,0000,0000,,So at the end of the quantum\Ncomputing program,
Dialogue: 0,0:12:10.93,0:12:13.75,Default,,0000,0000,0000,,all that's left is the correct answer,
Dialogue: 0,0:12:13.77,0:12:16.32,Default,,0000,0000,0000,,that we can then observe\Nhere in this universe.
Dialogue: 0,0:12:17.58,0:12:20.71,Default,,0000,0000,0000,,Now, if that doesn't make\Ncomplete sense to you, don't stress.
Dialogue: 0,0:12:20.74,0:12:21.78,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:12:21.81,0:12:23.03,Default,,0000,0000,0000,,You're in good company.
Dialogue: 0,0:12:24.20,0:12:27.37,Default,,0000,0000,0000,,Niels Bohr, one of\Nthe pioneers of this field,
Dialogue: 0,0:12:27.40,0:12:30.40,Default,,0000,0000,0000,,he once said that anyone\Nwho could contemplate quantum mechanics
Dialogue: 0,0:12:30.43,0:12:32.79,Default,,0000,0000,0000,,without being profoundly shocked,
Dialogue: 0,0:12:32.81,0:12:34.27,Default,,0000,0000,0000,,they haven't understood it.
Dialogue: 0,0:12:34.29,0:12:35.72,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:12:35.74,0:12:37.90,Default,,0000,0000,0000,,But you get an idea\Nof what we're up against,
Dialogue: 0,0:12:37.92,0:12:39.98,Default,,0000,0000,0000,,and why it's now up to us cryptographers
Dialogue: 0,0:12:40.01,0:12:41.37,Default,,0000,0000,0000,,to really step it up.
Dialogue: 0,0:12:42.67,0:12:44.76,Default,,0000,0000,0000,,And we have to do it fast,
Dialogue: 0,0:12:44.79,0:12:46.82,Default,,0000,0000,0000,,because quantum computers,
Dialogue: 0,0:12:46.84,0:12:49.87,Default,,0000,0000,0000,,they already exist in labs\Nall over the world.
Dialogue: 0,0:12:51.25,0:12:53.14,Default,,0000,0000,0000,,Fortunately, at this minute,
Dialogue: 0,0:12:53.17,0:12:55.84,Default,,0000,0000,0000,,they only exist\Nat a relatively small scale,
Dialogue: 0,0:12:55.86,0:12:58.93,Default,,0000,0000,0000,,still too small to break\Nour much larger cryptographic keys.
Dialogue: 0,0:13:00.13,0:13:01.81,Default,,0000,0000,0000,,But we might not be safe for long.
Dialogue: 0,0:13:02.97,0:13:05.46,Default,,0000,0000,0000,,Some folks believe that secret\Ngovernment agencies
Dialogue: 0,0:13:05.49,0:13:07.40,Default,,0000,0000,0000,,have already built a big enough one,
Dialogue: 0,0:13:07.42,0:13:09.40,Default,,0000,0000,0000,,and they just haven't told anyone yet.
Dialogue: 0,0:13:09.96,0:13:12.39,Default,,0000,0000,0000,,Some pundits say\Nthey're more like 10 years off.
Dialogue: 0,0:13:12.41,0:13:14.27,Default,,0000,0000,0000,,Some people say it's more like 30.
Dialogue: 0,0:13:15.16,0:13:18.02,Default,,0000,0000,0000,,You might think that\Nif quantum computers are 10 years away,
Dialogue: 0,0:13:18.04,0:13:21.11,Default,,0000,0000,0000,,surely that's enough time\Nfor us cryptographers to figure it out
Dialogue: 0,0:13:21.13,0:13:22.83,Default,,0000,0000,0000,,and to secure the internet in time.
Dialogue: 0,0:13:22.85,0:13:24.74,Default,,0000,0000,0000,,But unfortunately, it's not that easy.
Dialogue: 0,0:13:25.52,0:13:27.71,Default,,0000,0000,0000,,Even if we ignore\Nthe many years that it takes
Dialogue: 0,0:13:27.73,0:13:31.40,Default,,0000,0000,0000,,to standardize and deploy and then\Nroll out new encryption technology,
Dialogue: 0,0:13:31.42,0:13:33.75,Default,,0000,0000,0000,,in some ways we may already be too late.
Dialogue: 0,0:13:35.41,0:13:38.58,Default,,0000,0000,0000,,Smart digital criminals\Nand government agencies
Dialogue: 0,0:13:38.60,0:13:42.88,Default,,0000,0000,0000,,may already be storing\Nour most sensitive encrypted data
Dialogue: 0,0:13:42.91,0:13:45.50,Default,,0000,0000,0000,,in anticipation for\Nthe quantum future ahead.
Dialogue: 0,0:13:47.07,0:13:48.81,Default,,0000,0000,0000,,The messages of foreign leaders,
Dialogue: 0,0:13:50.10,0:13:51.46,Default,,0000,0000,0000,,of war generals
Dialogue: 0,0:13:52.65,0:13:54.82,Default,,0000,0000,0000,,or of individuals who question power,
Dialogue: 0,0:13:55.94,0:13:57.49,Default,,0000,0000,0000,,they're encrypted for now.
Dialogue: 0,0:13:58.49,0:14:00.09,Default,,0000,0000,0000,,But as soon as the day comes
Dialogue: 0,0:14:00.11,0:14:02.89,Default,,0000,0000,0000,,that someone gets their hands\Non a quantum computer,
Dialogue: 0,0:14:02.91,0:14:06.04,Default,,0000,0000,0000,,they can retroactively break\Nanything from the past.
Dialogue: 0,0:14:07.08,0:14:09.11,Default,,0000,0000,0000,,In certain government\Nand financial sectors
Dialogue: 0,0:14:09.13,0:14:10.54,Default,,0000,0000,0000,,or in military organizations,
Dialogue: 0,0:14:10.56,0:14:13.63,Default,,0000,0000,0000,,sensitive data has got to remain\Nclassified for 25 years.
Dialogue: 0,0:14:14.27,0:14:17.45,Default,,0000,0000,0000,,So if a quantum computer\Nreally will exist in 10 years,
Dialogue: 0,0:14:17.48,0:14:19.77,Default,,0000,0000,0000,,then these guys are already\N15 years too late
Dialogue: 0,0:14:19.79,0:14:21.50,Default,,0000,0000,0000,,to quantum-proof their encryption.
Dialogue: 0,0:14:22.86,0:14:24.83,Default,,0000,0000,0000,,So while many scientists around the world
Dialogue: 0,0:14:24.86,0:14:27.76,Default,,0000,0000,0000,,are racing to try to build\Na quantum computer,
Dialogue: 0,0:14:27.78,0:14:31.24,Default,,0000,0000,0000,,us cryptographers are urgently\Nlooking to reinvent encryption
Dialogue: 0,0:14:31.26,0:14:33.46,Default,,0000,0000,0000,,to protect us long before that day comes.
Dialogue: 0,0:14:34.72,0:14:37.69,Default,,0000,0000,0000,,We're looking for new,\Nhard mathematical problems.
Dialogue: 0,0:14:38.44,0:14:41.45,Default,,0000,0000,0000,,We're looking for problems that,\Njust like factorization,
Dialogue: 0,0:14:41.47,0:14:44.48,Default,,0000,0000,0000,,can be used on our smartphones\Nand on our laptops today.
Dialogue: 0,0:14:45.60,0:14:49.97,Default,,0000,0000,0000,,But unlike factorization,\Nwe need these problems to be so hard
Dialogue: 0,0:14:49.100,0:14:52.84,Default,,0000,0000,0000,,that they're even unbreakable\Nwith a quantum computer.
Dialogue: 0,0:14:54.37,0:14:57.97,Default,,0000,0000,0000,,In recent years, we've been digging around\Na much wider realm of mathematics
Dialogue: 0,0:14:57.100,0:14:59.52,Default,,0000,0000,0000,,to look for such problems.
Dialogue: 0,0:15:00.20,0:15:02.18,Default,,0000,0000,0000,,We've been looking at numbers and objects
Dialogue: 0,0:15:02.20,0:15:04.37,Default,,0000,0000,0000,,that are far more exotic\Nand far more abstract
Dialogue: 0,0:15:04.39,0:15:06.35,Default,,0000,0000,0000,,than the ones that you and I are used to,
Dialogue: 0,0:15:06.37,0:15:07.97,Default,,0000,0000,0000,,like the ones on our calculators.
Dialogue: 0,0:15:07.99,0:15:10.37,Default,,0000,0000,0000,,And we believe we've found\Nsome geometric problems
Dialogue: 0,0:15:10.40,0:15:11.80,Default,,0000,0000,0000,,that just might do the trick.
Dialogue: 0,0:15:12.38,0:15:15.45,Default,,0000,0000,0000,,Now, unlike those two-\Nand three-dimensional geometric problems
Dialogue: 0,0:15:15.47,0:15:19.17,Default,,0000,0000,0000,,that we used to have to try to solve\Nwith pen and graph paper in high school,
Dialogue: 0,0:15:19.19,0:15:23.42,Default,,0000,0000,0000,,most of these problems are defined\Nin well over 500 dimensions.
Dialogue: 0,0:15:24.45,0:15:28.21,Default,,0000,0000,0000,,So not only are they a little hard\Nto depict and solve on graph paper,
Dialogue: 0,0:15:28.23,0:15:31.70,Default,,0000,0000,0000,,but we believe they're even\Nout of the reach of a quantum computer.
Dialogue: 0,0:15:33.39,0:15:35.09,Default,,0000,0000,0000,,So though it's early days,
Dialogue: 0,0:15:35.11,0:15:39.62,Default,,0000,0000,0000,,it's here that we are putting our hope\Nas we try to secure our digital world
Dialogue: 0,0:15:39.64,0:15:41.61,Default,,0000,0000,0000,,moving into its quantum future.
Dialogue: 0,0:15:43.17,0:15:45.02,Default,,0000,0000,0000,,Just like all of the other scientists,
Dialogue: 0,0:15:45.05,0:15:47.21,Default,,0000,0000,0000,,we cryptographers are tremendously excited
Dialogue: 0,0:15:47.24,0:15:51.09,Default,,0000,0000,0000,,at the potential of living in a world\Nalongside quantum computers.
Dialogue: 0,0:15:52.84,0:15:54.99,Default,,0000,0000,0000,,They could be such a force for good.
Dialogue: 0,0:15:57.51,0:16:01.76,Default,,0000,0000,0000,,But no matter what\Ntechnological future we live in,
Dialogue: 0,0:16:04.87,0:16:09.72,Default,,0000,0000,0000,,our secrets will always be\Na part of our humanity.
Dialogue: 0,0:16:10.64,0:16:12.87,Default,,0000,0000,0000,,And that is worth protecting.
Dialogue: 0,0:16:13.56,0:16:14.71,Default,,0000,0000,0000,,Thanks.
Dialogue: 0,0:16:14.74,0:16:17.84,Default,,0000,0000,0000,,(Applause)