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  • Translator: Joseph Geni Reviewer: Camille Martínez

    譯者: Lilian Chiu 審譯者: Helen Chang

  • I'm in the business of safeguarding secrets,

    我的工作是保護秘密,

  • and this includes your secrets.

    包括你們的秘密。

  • Cryptographers are the first line of defense

    在一場已經激烈進行了 數世紀的戰爭中,

  • in an ongoing war that's been raging for centuries:

    密碼專家是第一道防線:

  • a war between code makers

    加密者和解密者之間的戰爭。

  • and code breakers.

    這是一場資訊戰。

  • And this is a war on information.

    現代,資訊的戰場是數位的。

  • The modern battlefield for information is digital.

    戰場橫跨你的手機、

  • And it wages across your phones,

    你的電腦,和網路。

  • your computers

    我們的工作是要設計系統來將 你的電子郵件和信用卡卡號、

  • and the internet.

    你的電話及文字訊息變成亂碼——

  • Our job is to create systems that scramble your emails and credit card numbers,

    也包括那些限制級的自拍——

  • your phone calls and text messages --

    (笑聲)

  • and that includes those saucy selfies --

    我們要讓這些加密資訊

  • (Laughter)

    只能夠被指定的接收者解開。

  • so that all of this information can only be descrambled

    一直到最近之前,

  • by the recipient that it's intended for.

    我們以為已經永久打贏了這場仗。

  • Now, until very recently,

    目前,各位的智慧手機 所用的加密技術

  • we thought we'd won this war for good.

    是我們認為無法破解, 且會一直無法破解的加密技術。

  • Right now, each of your smartphones is using encryption

    我們錯了,

  • that we thought was unbreakable and that was going to remain that way.

    因為量子電腦要出現了,

  • We were wrong,

    它們會讓局勢完全改觀。

  • because quantum computers are coming,

    在整個歷史上,密碼學和破解密碼 一直在玩貓捉老鼠的遊戲。

  • and they're going to change the game completely.

    十六世紀時,

  • Throughout history, cryptography and code-breaking

    蘇格蘭的瑪莉一世女王認為 她所發出的加密信件

  • has always been this game of cat and mouse.

    只有她的士兵能夠解開。

  • Back in the 1500s,

    但英格蘭的伊麗莎白 女王的解密者完全勝出。

  • Queen Mary of the Scots thought she was sending encrypted letters

    他們破解了瑪莉的信件,

  • that only her soldiers could decipher.

    發現她打算要刺殺伊麗莎白,

  • But Queen Elizabeth of England,

    後來,他們便砍下了瑪莉一世的頭。

  • she had code breakers that were all over it.

    幾世紀後,在二次大戰期間,

  • They decrypted Mary's letters,

    納粹使用恩尼格瑪密碼來溝通,

  • saw that she was attempting to assassinate Elizabeth

    他們認為這種更複雜的 加密方式是無法破解的。

  • and, subsequently, they chopped Mary's head off.

    但,接著,好樣的艾倫圖靈,

  • A few centuries later, in World War II,

    也就是發明了現代 電腦的那個傢伙,

  • the Nazis communicated using the Engima code,

    他打造了一台機器 來破解恩尼格瑪密碼。

  • a much more complicated encryption scheme that they thought was unbreakable.

    他破解了德國人的訊息,協助 阻止了希特勒和他的納粹德國。

  • But then good old Alan Turing,

    所以,這個故事 已經進行了數個世紀。

  • the same guy who invented what we now call the modern computer,

    密碼學家改進他們的加密方式,

  • he built a machine and used it to break Enigma.

    接著,破解密碼的人又反擊, 找出方式來破解。

  • He deciphered the German messages

    這場戰爭你來我往,競爭激烈。

  • and helped to bring Hitler and his Third Reich to a halt.

    直到七○年代,

  • And so the story has gone throughout the centuries.

    一些密碼學家有了重大的突破。

  • Cryptographers improve their encryption,

    他們發現了一種 極強大的加密方式,

  • and then code breakers fight back and they find a way to break it.

    叫做「公開金鑰密碼學」。

  • This war's gone back and forth, and it's been pretty neck and neck.

    和過去使用過的所有方法不同,

  • That was until the 1970s,

    打算交換機密資訊的雙方 不用事前交換秘密金鑰。

  • when some cryptographers made a huge breakthrough.

    公開金鑰密碼學的美好之處就在於

  • They discovered an extremely powerful way to do encryption

    它讓我們能夠和世界上 任何一個人進行安全的連結,

  • called "public-key cryptography."

    不論我們以前是否交換過資料,

  • Unlike all of the prior methods used throughout history, it doesn't require

    且它的速度超快,快到你我 都還沒意識到之前就已經完工。

  • that the two parties that want to send each other confidential information

    不論是你傳訊息約好友出來喝酒,

  • have exchanged the secret key beforehand.

    或者你是一間銀行, 要轉數十億美金給另一家銀行,

  • The magic of public-key cryptography is that it allows us to connect securely

    現代加密方式讓我們能夠

  • with anyone in the world,

    在幾毫秒的時間內 就完成安全的資料傳輸。

  • whether we've exchanged data before or not,

    讓這種魔法成為可能的聰明想法

  • and to do it so fast that you and I don't even realize it's happening.

    要仰賴困難的數學問題。

  • Whether you're texting your mate to catch up for a beer,

    密碼學家對於計算機 做不到的事都深感興趣。

  • or you're a bank that's transferring billions of dollars to another bank,

    比如,計算機可以 把任何兩個數字相乘,

  • modern encryption enables us to send data that can be secured

    不論數字多大。

  • in a matter of milliseconds.

    但換個方向——

  • The brilliant idea that makes this magic possible,

    先從乘積開始,接著問:

  • it relies on hard mathematical problems.

    「哪兩個數字相乘會得到 這個乘積?」——

  • Cryptographers are deeply interested in things that calculators can't do.

    那就是困難的問題。

  • For example, calculators can multiply any two numbers you like,

    若我請你找出哪兩個數字

  • no matter how big the size.

    相乘會得到 851,

  • But going back the other way --

    即使有計算機,

  • starting with the product and then asking,

    這裡大部分的人也很難 在這場演說結束前解出答案。

  • "Which two numbers multiply to give this one?" --

    如果我用大一點的數字,

  • that's actually a really hard problem.

    地球上就沒有一台 計算機能找出答案來。

  • If I asked you to find which two-digit numbers multiply to give 851,

    事實上,就連世界上 最快的超級電腦,

  • even with a calculator,

    也要花上比宇宙生命更長的時間

  • most people in this room would have a hard time finding the answer

    才找得出是哪兩個數字 相乘得到這個乘積。

  • by the time I'm finished with this talk.

    這個問題叫做 「整數的因數分解」,

  • And if I make the numbers a little larger,

    各位現在的智慧手機和筆電

  • then there's no calculator on earth that can do this.

    就是使用這個方法 來確保資料的安全性。

  • In fact, even the world's fastest supercomputer

    它是現代加密技術的基礎。

  • would take longer than the life age of the universe

    既然地球上所有的計算能力 結合起來都無法破解它,

  • to find the two numbers that multiply to give this one.

    因此我們密碼學家便認為 我們已經找到方法

  • And this problem, called "integer factorization,"

    可以永遠領先破解密碼者了。

  • is exactly what each of your smartphones and laptops is using right now

    也許我們太驕傲了,

  • to keep your data secure.

    因為就在我們自以為 已經打了勝仗時,

  • This is the basis of modern encryption.

    一群二十世紀的 物理學家加入戰局,

  • And the fact that all the computing power on the planet combined can't solve it,

    他們點出,宇宙的定律,

  • that's the reason we cryptographers thought we'd found a way

    也就是做為現代密碼學 基礎的那些定律,

  • to stay ahead of the code breakers for good.

    它們並非我們所想的那樣。

  • Perhaps we got a little cocky

    我們認為一個物體不可能 同時出現在兩個地方。

  • because just when we thought the war was won,

    並非如此。

  • a bunch of 20th-century physicists came to the party,

    我們以為沒有任何東西能夠

  • and they revealed that the laws of the universe,

    同時順時鐘又逆時鐘轉動。

  • the same laws that modern cryptography was built upon,

    但那並不正確。

  • they aren't as we thought they were.

    我們以為在宇宙 相對兩邊的兩個物體,

  • We thought that one object couldn't be in two places at the same time.

    相距數光年之遠,

  • It's not the case.

    它們就不可能即時影響彼此。

  • We thought nothing can possibly spin clockwise and anticlockwise

    我們又錯了。

  • simultaneously.

    人生似乎總是這樣,不是嗎?

  • But that's incorrect.

    就在你以為你什麼 都考慮了也準備好了,

  • And we thought that two objects on opposite sides of the universe,

    卻出現一票物理學家, 點出宇宙的基本定律

  • light years away from each other,

    和你所想的完全不一樣?

  • they can't possibly influence one another instantaneously.

    這把一切都搞砸了。

  • We were wrong again.

    (笑聲)

  • And isn't that always the way life seems to go?

    在非常微小的次原子領域中,

  • Just when you think you've got everything covered, your ducks in a row,

    在電子和光子的層級上,

  • a bunch of physicists come along

    我們知道且喜愛的物理標準定律,

  • and reveal that the fundamental laws of the universe are completely different

    都可以丟掉了。

  • to what you thought?

    這就要談到量子力學的定律了。

  • (Laughter)

    在量子力學中,

  • And it screws everything up.

    電子可以同時順時鐘 和逆時鐘轉動,

  • See, in the teeny tiny subatomic realm,

    光子可以同時位在兩個地方。

  • at the level of electrons and protons,

    聽起來很科幻,

  • the classical laws of physics,

    但那只是因為我們的宇宙 有著很瘋狂的量子特性,

  • the ones that we all know and love,

    這特性隱藏著沒被我們發現。

  • they go out the window.

    一直藏到二十世紀才被我們發現。

  • And it's here that the laws of quantum mechanics kick in.

    但現在我們知道了, 全世界都加入軍備競賽,

  • In quantum mechanics,

    比賽建造量子電腦——

  • an electron can be spinning clockwise and anticlockwise at the same time,

    量子電腦可以利用 這種怪異量子行為的力量。

  • and a proton can be in two places at once.

    這種電腦非常具有革命性

  • It sounds like science fiction,

    且非常強大,

  • but that's only because the crazy quantum nature of our universe,

    厲害到會讓現今最快的超級電腦

  • it hides itself from us.

    相較之下都變得很沒用。

  • And it stayed hidden from us until the 20th century.

    事實上,針對我們 很感興趣的某些問題,

  • But now that we've seen it, the whole world is in an arms race

    現今最快的超級電腦還比較 接近算盤,而非量子電腦。

  • to try to build a quantum computer --

    是的,算盤就是那些 有珠子在上頭的木製品。

  • a computer that can harness the power of this weird and wacky quantum behavior.

    量子電腦能模擬化學和生物過程,

  • These things are so revolutionary

    遠超過我們的標準電腦 能做到的程度。

  • and so powerful

    因此,量子電腦保證 能協助我們解決

  • that they'll make today's fastest supercomputer

    地球上一些最大的問題。

  • look useless in comparison.

    它們可以協助我們對抗全球飢荒,

  • In fact, for certain problems that are of great interest to us,

    處理氣候變遷,

  • today's fastest supercomputer is closer to an abacus

    針對我們目前沒輒的 疾病和流行病找出解藥,

  • than to a quantum computer.

    創造出超人類的人工智慧,

  • That's right, I'm talking about those little wooden things with the beads.

    還有,可能比上述這些都更重要的是

  • Quantum computers can simulate chemical and biological processes

    能協助我們了解宇宙的本質。

  • that are far beyond the reach of our classical computers.

    但,這麼驚人的潛能

  • And as such, they promise to help us solve some of our planet's biggest problems.

    也伴隨著極大的風險。

  • They're going to help us combat global hunger;

    還記得我先前談到的那些大數字嗎?

  • to tackle climate change;

    我指的不是 851。

  • to find cures for diseases and pandemics for which we've so far been unsuccessful;

    事實上,如果在座有人分心 去試著找出那些因數,

  • to create superhuman artificial intelligence;

    我來幫你從痛苦中解脫, 答案是 23 乘以 37。

  • and perhaps even more important than all of those things,

    (笑聲)

  • they're going to help us understand the very nature of our universe.

    我指的是在 857 之後 更大更大的那個數字。

  • But with this incredible potential

    雖然現今最快的超級電腦 花上宇宙一生的時間

  • comes an incredible risk.

    也無法找出那些因數,

  • Remember those big numbers I talked about earlier?

    但量子電腦能夠將 比那個數字更大許多的數字

  • I'm not talking about 851.

    輕易拆解成因數。

  • In fact, if anyone in here has been distracted

    量子電腦能破解目前用來保護你我

  • trying to find those factors,

    抵禦駭客的所有加密技術。

  • I'm going to put you out of your misery and tell you that it's 23 times 37.

    且輕輕鬆鬆就能辦到。

  • (Laughter)

    讓我這麼說:

  • I'm talking about the much bigger number that followed it.

    如果量子計算是一支長矛,

  • While today's fastest supercomputer couldn't find those factors

    那現代的加密系統,

  • in the life age of the universe,

    也就是數十年都沒被破解, 一直在保護我們的系統,

  • a quantum computer could easily factorize numbers

    它就像是用衛生紙做的盾牌。

  • way, way bigger than that one.

    任何人只要能夠使用量子電腦, 就等於拿到一把萬能鑰匙,

  • Quantum computers will break all of the encryption currently used

    在數位世界,他們想要 解鎖什麼就能解鎖什麼。

  • to protect you and I from hackers.

    他們能從銀行偷錢,

  • And they'll do it easily.

    控制經濟,

  • Let me put it this way:

    能讓醫院斷電或者發射核彈,

  • if quantum computing was a spear,

    還可以只是坐著,透過網路攝影機

  • then modern encryption,

    監視我們,不會被我們知道。

  • the same unbreakable system that's protected us for decades,

    在我們現在所使用的電腦上,

  • it would be like a shield made of tissue paper.

    像這台電腦上,資訊的基礎單位

  • Anyone with access to a quantum computer will have the master key

    叫做「位元」。

  • to unlock anything they like in our digital world.

    單一個位元可能有兩種狀態:

  • They could steal money from banks

    它可能是零或一。

  • and control economies.

    我媽在世界的另一端, 當我和她視訊通話時,

  • They could power off hospitals or launch nukes.

    她看到這張投影片一定會殺了我——

  • Or they could just sit back and watch all of us on our webcams

    (笑聲)

  • without any of us knowing that this is happening.

    我們其實只是發送一串 又一串的零和一給彼此,

  • Now, the fundamental unit of information on all of the computers we're used to,

    它們會在電腦及衛星間彈來彈去,

  • like this one,

    快速傳輸我們的資料。

  • it's called a "bit."

    位元非常有用,無庸置疑。

  • A single bit can be one of two states:

    事實上,我們目前 用科技所做的任何事,

  • it can be a zero or it can be a one.

    都受惠於這些好用的位元。

  • When I FaceTime my mum from the other side of the world --

    但,我們開始了解到位元很不擅長

  • and she's going to kill me for having this slide --

    模擬複雜的分子和粒子。

  • (Laughter)

    原因是因為,在某種意義上,

  • we're actually just sending each other long sequences of zeroes and ones

    次原子過程可以同時進行 兩件以上相反的事情,

  • that bounce from computer to computer, from satellite to satellite,

    因為它們遵循的是 這些怪異的量子力學規則。

  • transmitting our data at a rapid pace.

    所以,上個世紀末,

  • Bits are certainly very useful.

    一些非常聰明的物理學家 想出了一個天才點子:

  • In fact, anything we currently do with technology

    改用量子力學的原則來建造電腦。

  • is indebted to the usefulness of bits.

    在量子電腦上,資訊的基礎單位

  • But we're starting to realize

    叫做「量子位」。

  • that bits are really poor at simulating complex molecules and particles.

    是「量子位元」的簡稱。

  • And this is because, in some sense,

    量子位不只有零和一兩個狀態,

  • subatomic processes can be doing two or more opposing things

    它可以有無限多個狀態。

  • at the same time

    因為它可以同時是零和一的組合,

  • as they follow these bizarre rules of quantum mechanics.

    這種現象被我們稱為「疊加」。

  • So, late last century,

    當有兩個量子位疊加時,

  • some really brainy physicists had this ingenious idea:

    我們其實是在處理全部四種組合:

  • to instead build computers that are founded

    零和零、零和一、 一和零、一和一。

  • on the principles of quantum mechanics.

    有三個量子位時,

  • Now, the fundamental unit of information of a quantum computer,

    我們就有八種組合的疊加,

  • it's called a "qubit."

    以此類推。

  • It stands for "quantum bit."

    每當我們增加一個量子位,

  • Instead of having just two states, like zero or one,

    我們同時能用的

  • a qubit can be an infinite number of states.

    疊加組合數目就會加倍。

  • And this corresponds to it being some combination of both zero and one

    所以,當我們擴大規模, 使用許多量子位時,

  • at the same time,

    我們同時能夠用的組合數目

  • a phenomenon that we call "superposition."

    會是指數增加。

  • And when we have two qubits in superposition,

    從這點就可以略知 量子電腦的能力從何而來。

  • we're actually working across all four combinations

    在現代的加密技術中,

  • of zero-zero, zero-one, one-zero and one-one.

    我們的秘密金鑰,比如 那個大數字的兩個因數,

  • With three qubits,

    它們都是長串的零和一。

  • we're working in superposition across eight combinations,

    要找出它們,標準的電腦

  • and so on.

    必須把所有可能組合 一組一組試過,

  • Each time we add a single qubit, we double the number of combinations

    直到找到行得通的組合, 就破解了我們的加密。

  • that we can work with in superposition

    但在量子電腦上,

  • at the same time.

    只要有足夠的疊加量子位,

  • And so when we scale up to work with many qubits,

    就可以同時從 所有組合來擷取資訊。

  • we can work with an exponential number of combinations

    只要少數幾個步驟,

  • at the same time.

    量子電腦就能把所有 不正確的組合排除,

  • And this just hints at where the power of quantum computing is coming from.

    鎖定正確的組合,

  • Now, in modern encryption,

    接著揭露我們寶貴的秘密。

  • our secret keys, like the two factors of that larger number,

    在瘋狂的量子層級上,

  • they're just long sequences of zeroes and ones.

    發生的現象非常不可思議。

  • To find them,

    許多頂尖物理學家 所擁有的傳統知識是——

  • a classical computer must go through every single combination,

    你們要專心聽我說,別分神——

  • one after the other,

    每種組合其實是 在它自己的平行宇宙中,

  • until it finds the one that works and breaks our encryption.

    由它自己的量子電腦來檢查。

  • But on a quantum computer,

    每個組合加在一起, 就像一池水中的水波。

  • with enough qubits in superposition,

    錯誤的組合

  • information can be extracted from all combinations at the same time.

    會彼此抵消。

  • In very few steps,

    正確的組合

  • a quantum computer can brush aside all of the incorrect combinations,

    會強化、放大彼此。

  • home in on the correct one

    所以,在量子計算程式結束時,

  • and then unlock our treasured secrets.

    留下來的就只有正確答案,

  • Now, at the crazy quantum level,

    我們在這個宇宙中 就可以觀察到這個答案。

  • something truly incredible is happening here.

    如果你覺得還無法 完全理解,別擔心。

  • The conventional wisdom held by many leading physicists --

    (笑聲)

  • and you've got to stay with me on this one --

    你不孤單。

  • is that each combination is actually examined by its very own quantum computer

    尼爾斯 · 波耳是 這個領域的先鋒之一,

  • inside its very own parallel universe.

    他曾經說過,如果有人 在深入思考量子力學時

  • Each of these combinations, they add up like waves in a pool of water.

    沒被深深驚嚇到,

  • The combinations that are wrong,

    那他就還沒搞懂量子力學。

  • they cancel each other out.

    (笑聲)

  • And the combinations that are right,

    但你們多少了解了我們在對抗什麼,

  • they reinforce and amplify each other.

    及為什麼現在要靠 我們密碼學家來加把勁了。

  • So at the end of the quantum computing program,

    且我們的動作要快,

  • all that's left is the correct answer,

    因為量子電腦

  • that we can then observe here in this universe.

    已經存在於世界各地的實驗室中。

  • Now, if that doesn't make complete sense to you, don't stress.

    幸運的是,此刻,

  • (Laughter)

    它們相對還算小規模的電腦,