How quantum physics can make encryption stronger | Vikram Sharma

翻译人员: Hong Li 校对人员: Yolanda Zhang

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

最近，我们见识到了 网络攻击对商业世界的影响。

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

像摩根大通、雅虎、家得宝和 塔吉特百货这些公司的数据泄露，

have caused losses of hundreds of millions

导致了数亿美元，

and in some cases, billions of dollars.

甚至数十亿美元的损失。

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

再来几次这样的攻击， 整个世界经济就会崩溃。

And the public sector has not been immune, either.

公共领域也不能幸免。

In 2012 to 2014,

从2012到2014年，

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

美国人事管理办公室 发生了非常严重的数据泄露。

Security clearance and fingerprint data was compromised,

安全许可和指纹信息被窃取，

affecting 22 million employees.

影响到2200万雇员。

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

你们也许还听说了， 某些政府资助的黑客，

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

试图用窃取的数据 影响一些国家的大选结果。

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

最近的两起，一起是德国联邦议院

from the Bundestag, the national Parliament of Germany,

大规模数据遭窃事件，

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

一起是美国民主党全国委员会 电子邮件遭窃事件。

The cyber threat is now affecting our democratic processes.

网络威胁已经影响到 我们的民主进程。

And it's likely to get worse.

而且有愈演愈烈的趋势。

As computer technology is becoming more powerful,

计算机技术越发达，

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

我们用来保护数据的 手段就越脆弱。

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

尤其是一种新的计算机技术，

called quantum computing,

叫做量子计算机，

which leverages microscopic properties of nature

它利用自然界的微观粒子

to deliver unimaginable increases in computational power.

来大幅增加计算机的运算能力。

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

它的运算能力强大到 可以破解我们今天所用的

that we use today.

许多加密系统。

So is the situation hopeless?

那么我们是不是毫无希望了呢？

Should we start packing our digital survival gear

我们是不是该开始 收拾电子生存装备

and prepare for an upcoming data apocalypse?

来迎接即将到来的数据末日呢？

I would say, not yet.

我认为，还没到那一步。

Quantum computing is still in the labs,

量子计算机还只是存在于实验室里，

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

离实际运用还需要数年的时间。

More important,

更重要的是，

there have been major breakthroughs in the field of encryption.

加密领域已经出现了许多重大突破。

For me, this is a particularly exciting time

对我而言，这是安全通讯历史上

in the history of secure communications.

非常令人兴奋的时代。

About 15 years ago,

大约15年前，

when I learned of our new-found ability

我了解到我们解锁了新的技能，

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

能制造出自然界 不存在的量子效应。

I was excited.

我非常兴奋。

The idea of applying the fundamental laws of physics

利用物理学的基本定律

to make encryption stronger

来推进加密技术发展，

really intrigued me.

这个想法让我激动不已。

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

今天，一些选定的公司 和实验室，包括我的在内，

are maturing this technology for practical applications.

将这项技术推进到了 实际应用的阶段。

That's right.

没错。

We are now preparing to fight quantum with quantum.

我们打算用量子来对抗量子。

So how does this all work?

怎么来实现呢？

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

首先，我们来快速了解 一下加密的世界。

For that, you'll need a briefcase,

你需要一个公文包，

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

你有一些重要的文件 要送给你的好朋友，詹姆斯·邦德，

and a lock to keep it all safe.

要锁起来，保证安全。

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

因为这些材料是最高机密， 我们要用一个超级先进的公文包。

It has a special combination lock

它配有一把特殊的密码锁，

which, when closed,

一旦锁上，

converts all the text in the documents to random numbers.

就会把文件的内容 转换为随机的数字。

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

因此你只要把文件放进去，锁上，

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

这个时候文件已经转换为 随机的数字了，

and you send the briefcase to James.

你把这个公文包送给詹姆斯。

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

公文包还没送到的时候， 你打电话告诉他密码。

When he gets the briefcase, he enters the code,

一旦他拿到公文包，输入密码，

the documents get unscrambled, and voilà,

文件破译完成，简直完美，

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

你成功地把一份加密信息 传递给了詹姆斯·邦德。

(Laughter)

（笑声）

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

一个好玩的例子，但是它 说明了加密的3个重点。

The code -- we call this an encryption key.

密码——我们称之为加密钥匙。

You can think of it as a password.

你可以把它想像成密码。

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

告诉詹姆斯密码的那通电话。

We call this key exchange.

我们称之为秘钥传递。

This is how you ensure

这保证我们

you get the encryption key securely to the right place.

能将秘钥安全的送到指定地点。

And the lock, which encodes and decodes the document.

以及用来加密和解密文件的锁。

We call this an encryption algorithm.

我们称之为加密算法。

Using the key, it encodes the text in the documents

通过秘钥，它将文件中的内容

to random numbers.

转换为随机的数字。

A good algorithm will encode in such a way

一个好的算法能够做到这一点，

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

没有秘钥的话很难将密码破解。

What makes encryption so important

算法的重要性就在于

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

如果有人得到了公文包，把它打开，

without the encryption key and the encryption algorithm,

没有秘钥，不知道加密算法，

they wouldn't be able to read the documents.

就无法读取文档里的内容。

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

得到的只是一些随机的数字。

Most security systems rely on a secure method for key exchange

大部分的安全系统 都依赖于安全的秘钥传递方式，

to communicate the encryption key to the right place.

将秘钥传递到正确的地方。

However, rapid increases in computational power

然而，迅速增长的计算能力

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

危及到了我们目前所使用的 许多秘钥传递方式。

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

举一个例子，我们现在 应用非常广泛的系统——RSA。

When it was invented, in 1977,

它在1977年被发明出来的时候，

it was estimated that it would take 40 quadrillion years

要花大约4千万亿年，

to break a 426-bit RSA key.

才能破解一个426位的RSA秘钥。

In 1994, just 17 years later,

而到了1994年， 仅仅才过了17年，

the code was broken.

这个密码就被破解了。

As computers have become more and more powerful,

随着计算机性能越来越强，

we've had to use larger and larger codes.

我们需要的密码也越来越长。

Today we routinely use 2048 or 4096 bits.

现在我们经常会使用 2048或者4096位的密码。

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

如您所见，加密者和解密者 之间的战斗正在进行，

to outwit each other.

都想战胜对方。

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

今后10到15年， 量子计算机的到来，

they will even more rapidly crack the complex mathematics

将会更快地破解复杂的数学算法，

that underlies many of our encryption systems today.

这些算法是今天 我们使用的加密系统的基础。

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

事实上，量子计算机 将把我们的安全城堡

into a mere house of cards.

变成一触即倒的纸牌屋。

We have to find a way to defend our castle.

我们要设法保护我们的城堡。

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

近几年出现了许多研究机构，

looking at using quantum effects to make encryption stronger.

研究如何用量子效应来增强加密。

And there have been some exciting breakthroughs.

人们已经取得了一些 令人兴奋的突破。

Remember those three things important for encryption --

还记得加密的3个重点吗？

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

高质量的秘钥，安全的秘钥传递 和很强的算法。

Well, advances in science and engineering

然而，科学和工程学的进步，

are putting two of those three elements at risk.

已经危及到了其中2个重点。

First of all, those keys.

首当其冲的就是秘钥。

Random numbers are the foundational building blocks of encryption keys.

随机数字是构成秘钥的基础。

But today, they're not truly random.

但到了今天， 它们不再是真正随机了。

Currently, we construct encryption keys

目前，我们生成秘钥，

from sequences of random numbers generated from software,

是根据随机数字频率， 靠软件生成的，

so-called pseudo-random numbers.

我们称之为伪随机数字。

Numbers generated by a program or a mathematical recipe

程序或者数学方法生成的数字，

will have some, perhaps subtle, pattern to them.

总会有一些，也许并不 那么明显的规律在里面。

The less random the numbers are,

这些数字的随机性越低，

or in scientific terms, the less entropy they contain,

或者用术语来讲， 包含的墒越低，

the easier they are to predict.

它们就越容易被预测到。

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

最近，有些赌场就被攻击了， 攻击的方式很有创意。

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

他们对准老虎机拍摄一段时间，

and then analyzed.

然后进行分析。

This allowed the cyber criminals

网络罪犯们

to reverse engineer the pseudo-random number generator

利用逆向工程，制造出转盘背后的

behind the spinning wheels.

伪随机数字生成器。

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

这样一来他们就有很大几率 预测到转盘的转动，

enabling them to make big financial gains.

从而赚到大笔金钱。

Similar risks apply to encryption keys.

秘钥也同样不安全。

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

拥有一个真正的随机数字生成器 对于生成安全的密码而言很重要。

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

数年来，研究者们一直在努力制造 真正的随机数字生成器。

But most designs to date are either not random enough,

但大部分的设计，要么不够随机，

fast enough or aren't easily repeatable.

要么不够快，要么很难重复使用。

But the quantum world is truly random.

但是量子的世界是真正随机的。

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

利用这种真正的随机性非常重要。

Devices that can measure quantum effects

能够测量量子效应的装置

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

可以非常快速地生成 连续不断的随机数字流。

Foiling all those would-be casino criminals.

刚刚说的赌场犯罪再无上演可能。

A select group of universities and companies around the world

来自世界各地的数所大学和公司

are focused on building true random number generators.

在集中精力制造 真正的随机数字生成器。

At my company, our quantum random number generator

在我的公司，我们的 量子随机数字生成器

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

诞生于一张2米长1米宽的光学桌。

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

之后我们把它缩小到一个盒子大小。

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

到今天，已经可以把它装到一张PCI卡上， 插到一台普通的计算机上。

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

这是世界上速度最快的， 真正随机的数字生成器。

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

它通过测量量子效应， 每秒可以生成10亿个随机数字。

And it's in use today to improve security

今天已经被广泛用于世界各地，

at cloud providers, banks and government agencies

来提升云服务提供商、 银行和政府机构的

around the world.

安全性。

(Applause)

（掌声）

But even with a true random number generator,

但是，即便有了真正的 随机数字生成器，

we've still got the second big cyber threat:

我们还面临 第2个大的网络安全威胁：

the problem of secure key exchange.

那就是秘钥的安全传递问题。

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

目前的秘钥传输技术 无法对抗量子计算机。

The quantum solution to this problem

而针对这一问题的量子解决方案，

is called quantum key distribution or QKD,

叫做量子秘钥分发，简称QKD，

which leverages a fundamental, counterintuitive characteristic

它利用了量子力学一个基础的

of quantum mechanics.

违反直觉的特性。

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

观察微观粒子这个行为， 会改变这个粒子。

Let me give you an example of how this works.

我举个例子来说明。

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

我们再来回想一下， 要把密码交给詹姆斯·邦德。

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

不过这一次，我们不给他打电话，

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

我们利用量子效应， 用一束激光携带这个密码，

and send it over standard optic fiber to James.

通过普通的光纤传递给詹姆斯。

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

我们假设诺博士想拿到这个密码。

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

幸运的是，诺博士在尝试拦截 这个量子秘钥的过程中

will leave fingerprints that James and you can detect.

会留下电子指纹， 詹姆斯和你都能察觉到。

This allows those intercepted keys to be discarded.

这样被拦截的秘钥就会作废。

The keys which are then retained

而留下来的秘钥

can be used to provide very strong data protection.

能够为数据提供强大的保护。

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

因为这种安全机制 是以物理学基本原理为基础，

a quantum computer, or indeed any future supercomputer

量子计算机，或者未来的 任何超级计算机，

will not be able to break it.

都不可能破解它。

My team and I are collaborating with leading universities

我和我的团队正在跟许多顶尖大学

and the defense sector

以及国防部门一起合作，

to mature this exciting technology

改进这项激动人心的技术，

into the next generation of security products.

发展下一代安全产品。

The internet of things is heralding a hyperconnected era

物联网预示了一个 高度互联时代的来临，

with 25 to 30 billion connected devices forecast by 2020.

预计到2020年将会有 250-300亿设备接入互联网。

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

要想我们的社会 在物联网世界正常运作，

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

那么对这些互联设备系统的 信任就至关重要。

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

我们相信量子技术 对于建立这种信任会非常重要，

enabling us to fully benefit from the amazing innovations

它将保证我们充分享受 这些神奇的创新，

that are going to so enrich our lives.

享受这些能让我们的生活 丰富多彩的创新。

Thank you.

谢谢大家。

(Applause)

（掌声）