How quantum physics can make encryption stronger | Vikram Sharma

譯者: Lilian Chiu 審譯者: Helen Chang

Recently, we've seen the effects of cyber attacks on the business world.

近期，我們看到了網路攻擊 對商業世界的影響。

Data breaches at companies like JP Morgan, Yahoo, Home Depot and Target

摩根大通、雅虎、家得寶， 以及目標百貨都遇到了資料外洩，

have caused losses of hundreds of millions

導致數億美元的損失，

and in some cases, billions of dollars.

在一些案例中，甚至是數十億美元。

It wouldn't take many large attacks to ravage the world economy.

不用太多次大型攻擊 就足以毀滅世界經濟。

And the public sector has not been immune, either.

而公部門也無法倖免。

In 2012 to 2014,

2012 年到 2014 年，

there was a significant data breach at the US Office of Personnel Management.

美國人事管理辦公室 發生嚴重的資料外洩。

Security clearance and fingerprint data was compromised,

危及到安全許可和指紋資料，

affecting 22 million employees.

影響到 2200 萬員工。

And you may have heard of the attempt by state-sponsored hackers

你們可能也聽過，有國家贊助的駭客

to use stolen data to influence election outcomes in a number of countries.

用偷來的資料來影響選舉結果， 在好幾個國家都發生過。

Two recent examples are the compromise of a large amount of data

兩個近期的例子

危及大量的德國聯邦議院資料

from the Bundestag, the national Parliament of Germany,

and the theft of emails from the US Democratic National Committee.

和遭竊的美國民主黨 全國委員會電子郵件。

The cyber threat is now affecting our democratic processes.

網路的威脅現在 影響了我們的民主過程。

And it's likely to get worse.

且很有可能會繼續惡化。

As computer technology is becoming more powerful,

隨著電腦科技變得更強大，

the systems we use to protect our data are becoming more vulnerable.

我們用來保護資料的 系統變得更脆弱。

Adding to the concern is a new type of computing technology,

要擔心的還不只如此，

有一種新的運算技術叫量子運算，

called quantum computing,

which leverages microscopic properties of nature

利用大自然的微觀特性，

to deliver unimaginable increases in computational power.

得以無法想像地增大運算能力。

It's so powerful that it will crack many of the encryption systems

它強大到可以破解

我們現今使用的許多加密系統。

that we use today.

So is the situation hopeless?

所以，沒有希望了嗎？

Should we start packing our digital survival gear

我們應該開始打包數位生存用具，

and prepare for an upcoming data apocalypse?

準備面對即將到來的 資料世界末日嗎？

I would say, not yet.

我會說，時候未到。

Quantum computing is still in the labs,

量子運算仍然在實驗階段，

and it will take a few years until it's put to practical applications.

還要幾年才能實際應用。

More important,

更重要的，

there have been major breakthroughs in the field of encryption.

在加密領域已經有了重大突破。

For me, this is a particularly exciting time

對我來說，這是安全通訊史上

in the history of secure communications.

特別讓人振奮的時刻。

About 15 years ago,

大約十五年前，

when I learned of our new-found ability

我學到了我們新發現的能力：

to create quantum effects that don't exist in nature,

創造出自然中不存在的量子效應，

I was excited.

當時我好興奮。

The idea of applying the fundamental laws of physics

應用物理的基礎定律

to make encryption stronger

來強化加密的想法，

really intrigued me.

的確激起我的興趣。

Today, a select groups of companies and labs around the world, including mine,

現今世界各地幾個精選的公司 和實驗室，包括我的在內，

are maturing this technology for practical applications.

在使這項技術變成熟， 以做實際應用。

That's right.

沒錯。

We are now preparing to fight quantum with quantum.

我們正準備用量子來對抗量子。

So how does this all work?

這是怎麼運作的？

Well, first, let's take a quick tour of the world of encryption.

首先讓我們快速瀏覽加密的世界。

For that, you'll need a briefcase,

你需要一個公事包，

some important documents that you want to send your friend, James Bond,

要寄一些重要的文件 給朋友詹姆士龐德，

and a lock to keep it all safe.

還要一個鎖來確保安全。

Because the documents are top secret, we're going to use an advanced briefcase.

因為這是最高機密文件， 我們要用進階的公事包。

It has a special combination lock

它有個特殊的密碼鎖，

which, when closed,

當鎖上時，

converts all the text in the documents to random numbers.

會把文件中所有的文字 轉換成隨機數字。

So you put your documents inside, close the lock --

把文件放進去，上鎖，

at which point in time the documents get converted to random numbers --

這時文件就會被轉為隨機數字，

and you send the briefcase to James.

然後你就把公事包寄給詹姆士。

While it's on its way, you call him to give him the code.

當公事包在運送路上時， 你打電話給他，把密碼給他。

When he gets the briefcase, he enters the code,

當他收到公事包時，他輸入密碼，

the documents get unscrambled, and voilà,

文件被還原，然後，看哪，

you've just sent an encoded message to James Bond.

你剛剛已經把加密訊息 傳給詹姆士龐德了。

(Laughter)

（笑聲）

A fun example, but it does illustrate three things important for encryption.

這是個有趣的例子，但它確實 描述出了加密的三項重點。

The code -- we call this an encryption key.

密碼──我們稱之為「加密金鑰」。

You can think of it as a password.

你可以把它想像成密碼。

The call to James to give him the code for the combination lock.

打電話給詹姆士龐德， 給他密碼鎖的密碼。

We call this key exchange.

我們稱之為「金鑰交換」。

This is how you ensure

這就是你如何確保

you get the encryption key securely to the right place.

你安全地把加密金鑰送到對的地方。

And the lock, which encodes and decodes the document.

還有鎖，它能將文件編碼和解碼。

We call this an encryption algorithm.

成為「加密演算法」。

Using the key, it encodes the text in the documents

用金鑰，就能把文件中的文字編碼

to random numbers.

成為隨機數字。

A good algorithm will encode in such a way

如果用好的演算法來編碼，

that without the key it's very difficult to unscramble.

沒有金鑰就會非常難 將文件恢復原狀。

What makes encryption so important

加密之所以這麼重要，

is that if someone were to capture the briefcase and cut it open

是因為如果有人劫了 公事包並把它割開，

without the encryption key and the encryption algorithm,

沒有加密金鑰和加密演算法，

they wouldn't be able to read the documents.

他們無法閱讀文件的內容。

They would look like nothing more than a bunch of random numbers.

文件看起來就只是 一堆隨機數字而已。

Most security systems rely on a secure method for key exchange

大部分的保安系統都依靠 一種安全方法來交換金鑰，

to communicate the encryption key to the right place.

把加密金鑰送去對的地方。

However, rapid increases in computational power

然而，運算能力快速增加，

are putting at risk a number of the key exchange methods we have today.

讓我們現今會用的幾種 金鑰交換方法變得有風險。

Consider one of the very widely used systems today -- RSA.

試想一種現今 廣為使用的系統 RSA。

When it was invented, in 1977,

它在 1977 年被發明出來，

it was estimated that it would take 40 quadrillion years

當時估計需花上 40 萬億年 （1000 的五次方）

to break a 426-bit RSA key.

才能破解 426 位元的 RSA 金鑰。

In 1994, just 17 years later,

1994 年，即 17 年後，

the code was broken.

該密碼被破解了。

As computers have become more and more powerful,

隨著電腦變得越來越強大，

we've had to use larger and larger codes.

我們要用的密碼也越來越長。

Today we routinely use 2048 or 4096 bits.

現今，我們通常使用到 2048 或 4096 位元。

As you can see, code makers and breakers are engaged in an ongoing battle

如你們所見，製作密碼的人 和破解密碼的人在進行一場戰爭，

to outwit each other.

要以智取勝。

And when quantum computers arrive in the next 10 to 15 years,

當量子電腦在接下來的 十到十五年間問世時，

they will even more rapidly crack the complex mathematics

它們會用更快的速度

破解現今許多加密系統 背後的複雜數學。

that underlies many of our encryption systems today.

Indeed, the quantum computer is likely to turn our present security castle

的確，量子電腦有可能 把我們目前的安全城堡

into a mere house of cards.

轉變成紙牌屋。

We have to find a way to defend our castle.

我們得要找出一種方式 來防守我們的城堡。

There's been a growing body of research in recent years

近年來，越來越多研究

looking at using quantum effects to make encryption stronger.

在探究如何用量子效應來加強加密，

And there have been some exciting breakthroughs.

並且已有些讓人興奮的突破。

Remember those three things important for encryption --

記得加密的那三項重點嗎？

high-quality keys, secure key exchange and a strong algorithm?

高品質金鑰、安全的金鑰交換， 以及強大的演算法。

Well, advances in science and engineering

科學和工程的進步，

are putting two of those three elements at risk.

讓三項中的兩項都遭受到風險。

First of all, those keys.

首先，那些金鑰。

Random numbers are the foundational building blocks of encryption keys.

隨機數字是加密金鑰的基礎建材。

But today, they're not truly random.

但現今，它們不是真正隨機的。

Currently, we construct encryption keys

目前，我們建立加密金鑰時，

from sequences of random numbers generated from software,

用的是軟體所產生出來的 一系列隨機數字，

so-called pseudo-random numbers.

它們是所謂的偽隨機數字。

Numbers generated by a program or a mathematical recipe

用程式或是數學方法 所產生出來的數字，

will have some, perhaps subtle, pattern to them.

會有一些也許很難捉摸的模式存在。

The less random the numbers are,

數字越不隨機，

or in scientific terms, the less entropy they contain,

或用科學的說法， 它們所含的熵越少，

the easier they are to predict.

就越容易被預測。

Recently, several casinos have been victims of a creative attack.

近期，許多賭場就成了 一項創意攻擊的受害者。

The output of slot machines was recorded over a period of time

有人針對吃角子老虎機的輸出值 做了一段時間的記錄，

and then analyzed.

接著做分析。

This allowed the cyber criminals

這讓網路罪犯得以

to reverse engineer the pseudo-random number generator

逆向製造出轉輪背後的

偽隨機數字產生器。

behind the spinning wheels.

And allowed them, with high accuracy, to predict the spins of the wheels,

讓他們能預測轉輪的結果， 且正確率很高，

enabling them to make big financial gains.

就能從中大撈一筆。

Similar risks apply to encryption keys.

加密金鑰也有類似的風險。

So having a true random number generator is essential for secure encryption.

對安全加密而言，產生出 真正的隨機數字是很重要的。

For years, researchers have been looking at building true random number generators.

多年來，研究者一直在研究 真實隨機數字的產生器。

But most designs to date are either not random enough,

但現今大部分的設計 若不是不夠隨機、不夠快，

fast enough or aren't easily repeatable.

就是不容易重覆。

But the quantum world is truly random.

但量子世界是真正隨機的。

So it makes sense to take advantage of this intrinsic randomness.

利用這種天生的隨機性 是合理的做法。

Devices that can measure quantum effects

能夠測量量子效應的裝置

can produce an endless stream of random numbers at high speed.

能快速產生出無限多的隨機數字。

Foiling all those would-be casino criminals.

讓那些想成為賭場罪犯的人受挫。

A select group of universities and companies around the world

全世界一些被選中的大學和公司

are focused on building true random number generators.

正專注發展真正的隨機數字產生器。

At my company, our quantum random number generator

在我的公司，我們的 量子隨機數字產生器

started life on a two meter by one meter optic table.

誕生在一張 2 公尺長 1 公尺寬的光學桌子上。

We were then able to reduce it to a server-size box.

後來我們想辦法將它縮小為 伺服器大小的盒子。

Today, it's miniaturized into a PCI card that plugs into a standard computer.

現今它已微型化至 PCI 擴充卡中， 可以插入標準電腦。

This is the world's fastest true random number generator.

這是世界上最快速的 真實隨機數字產生器。

It measures quantum effects to produce a billion random numbers per second.

它會測量量子效應，每秒鐘 產生出十億個隨機數字。

And it's in use today to improve security

現今它被用來改善安全性，

at cloud providers, banks and government agencies

使用者包括全世界的 雲端服務提供者、銀行，

around the world.

及政府機關。

(Applause)

（掌聲）

But even with a true random number generator,

但即使有了真實隨機數字產生器，

we've still got the second big cyber threat:

我們還要面對第二大的網路威脅：

the problem of secure key exchange.

安全金鑰交換的問題。

Current key exchange techniques will not stand up to a quantum computer.

目前的金鑰交換技術 對付不了量子電腦。

The quantum solution to this problem

這個問題的量子解決方案

is called quantum key distribution or QKD,

叫做量子金鑰傳輸，簡稱 QKD，

which leverages a fundamental, counterintuitive characteristic

它能充份發揮量子力學中

違背直覺的基礎特性：

of quantum mechanics.

The very act of looking at a quantum particle changes it.

探究量子粒子的動作會招來改變。

Let me give you an example of how this works.

讓我舉例說明這是怎麼運作的。

Consider again exchanging the code for the lock with James Bond.

再次想像和詹姆士龐德交換鎖的密碼。

Except this time, instead of a call to give James the code,

不過這一次，不是打電話 給詹姆士去告訴他密碼，

we're going to use quantum effects on a laser to carry the code

我們要用雷射的量子效應 來攜帶這個密碼，

and send it over standard optic fiber to James.

然後用標準光纖將密碼傳給詹姆士。

We assume that Dr. No is trying to hack the exchange.

我們假設諾博士打算要駭入這項交換。

Luckily, Dr. No's attempt to intercept the quantum keys while in transit

幸運的是，在諾博士試圖攔截 量子金鑰傳輸的時候，

will leave fingerprints that James and you can detect.

會留下指紋，讓詹姆士 和你可以偵測得到。

This allows those intercepted keys to be discarded.

這麼一來，就可以 廢除被攔劫的金鑰。

The keys which are then retained

而留下來的金鑰，

can be used to provide very strong data protection.

就能被用來提供非常強的資料保護。

And because the security is based on the fundamental laws of physics,

因為安全性的基礎是物理的基礎定律，

a quantum computer, or indeed any future supercomputer

量子電腦，或是任何未來的超級電腦，

will not be able to break it.

都無法破解它。

My team and I are collaborating with leading universities

我和團隊與頂尖大學

and the defense sector

以及國防部門合作，

to mature this exciting technology

使這項讓人興奮的技術能更成熟，

into the next generation of security products.

成為下一代的安全產品。

The internet of things is heralding a hyperconnected era

物聯網預示了超連結時代的來臨，

with 25 to 30 billion connected devices forecast by 2020.

預測到 2020 年會有 250~300 億個連結的裝置。

For the correct functioning of our society in an IoT world,

要在物聯網的世界裡 讓社會能正確地運作，

trust in the systems that support these connected devices is vital.

對於這些連接設備的 支撐系統之信任至關重要。

We're betting that quantum technologies will be essential in providing this trust,

我們押寶量子技術 將會是提供這種信任的關鍵，

enabling us to fully benefit from the amazing innovations

能使我們能充分受益於

豐富我們生活的驚人創新。

that are going to so enrich our lives.

Thank you.

謝謝。

(Applause)

（掌聲）