You say you are not a typical cyberlibertarian. How do you define this
term? And why don鈥檛 you see yourself as one?
Cyberlibertarians tend to see the Internet as leading to the abolition of
governments. Their idea is that given the advent of anonymous e-mail, digital
cash and so on, the state will no longer be able to support itself by raising
revenue through taxation. I don鈥檛 think this is likely or desirable. Think what
England was like when the government didn鈥檛 really exist: anyone with any wealth
or property had to design their house to withstand infantry-strength assault.
That鈥檚 not efficient. National governments and policemen will survive the
electronic revolution because of the efficiencies they create.
Because your team is a world leader in research into computer security,
you鈥檝e been chosen as one of the finalists to design a new encryption standard
for the US. Do you think you鈥檒l win?
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The Data Encryption Standard currently used by the US banks and other
organisations is no longer secure enough from attack. The US government invited
the crypto community to develop what they鈥檙e calling the Advanced Encryption
Standard. Along with Eli Biham from the Technion in Israel and Lars Knudsen from
the University of Bergen in Norway, I鈥檝e invented a cipher that鈥檚 been selected
for the final. People are sceptical about whether the US government will pick a
non-American winner, but I think there鈥檚 a general perception that our system is
the most secure of the finalists. It鈥檚 not the fastest. But then we designed
ours on the assumption that it needs to keep stuff secret for the next hundred
years鈥� despite advances in technology and in the mathematics of
cryptography.
Politicians and others have expressed alarm at the prospect of criminals
using encryption to keep their e-mails secret and evade detection. You say this
concern is bogus鈥攚hy?
It鈥檚 based on a misconception of what law enforcement operations are like. At
present, the police have little interest in intercepting and reading the
transcripts of phone conversations. It鈥檚 costly and tedious and rarely justified
except in serious, high-budget investigations. Instead, what the police are
mostly after is traffic logs鈥攊nformation on who called or e-mailed whom,
at what time and for how long. Criminals understand this and try to make their
communications as unobtrusive as possible. In Britain, the main threat to police
intelligence gathering comes from the prepaid mobile phone, not e-mail
encryption, because you can buy one without giving out your name and address. In
other words, the users of these devices can鈥檛 be traced, so they鈥檙e ideal for
running an operation such as drugs dealing.
But what about terrorists?
The idea that information technology has revolutionised the way terrorists
run their operations has been exaggerated. Take the IRA. We know from a recent
court case that this organisation still writes down the orders for its active
service units on pieces of cigarette paper, which they wrap in cling film so the
courier can carry the orders through customs in his mouth. That鈥檚 how real
terrorists keep information to themselves.
But isn鈥檛 the point that the terrorists will soon be abandoning the cling
film and using cleverly encrypted e-mails instead?
Encryption alone won鈥檛 help them. If I were to hold a three-hour encrypted
conversation with someone in the Medell铆n drug cartel, it would be a dead
giveaway. In routine monitoring, GCHQ (Britain鈥檚 signals intelligence service)
would pick up the fact that there was encrypted traffic and would instantly mark
down my phone as being suspect. Quite possibly the police would then send in the
burglars to put microphones in all over my house. In circumstances like this,
encryption does not increase your security. It immediately and rapidly decreases
it. You are mad to use encryption if you are a villain.
You鈥檙e a well-known critic of the suggestion that governments should have
access to the keys needed to decode people鈥檚 encrypted messages and duplicate
their electronic signatures. Why are you so opposed to such 鈥渢hird-party鈥� access
schemes?
It鈥檚 a flawed idea designed for a world which no longer exists, where the
main users of encryption were the military, the intelligence services and the
diplomatic corps. Now encryption is widespread and used largely in systems whose
security is in the interests of law enforcement, such as cash machines and
burglar alarms. The authorities are going to have terrible difficulty in trying
to draft any third-party legislation that blesses encryption applications that
are good for law enforcement and curses those that aren鈥檛. The argument that
criminals will use encryption is bogus. The argument that governments need to
hold keys to unlock people鈥檚 encrypted files to solve crime is bogus. The real
issues are more complex and much nastier.
So what sorts of issue should we be worried about?
Here鈥檚 one example. Britain鈥檚 Civil Service is adopting an e-mail security
protocol called 鈥渃loud cover鈥�. In this scheme, departmental security officers
will get copies of the electronic keys that are used not just to de-crypt
messages, but also to create the digital signatures on them. This will enable
ministers to plausibly deny any responsibility for information that leaks from
their department. They can simply claim that the message was forged鈥攁nd by
the very official whose job it was to stop leaks.
But as far as freedom of information goes, this scheme is a disaster. If in a
decade鈥檚 time you are awarded access to an embarrassing government document, the
officials of the day could use the keys they hold to substitute a forgery and
you鈥檇 never be able to know. Even if they gave you a genuine document, you
couldn鈥檛 be sure it hadn鈥檛 been forged. This is the sort of horrible complexity
that third-party key schemes bring into real systems.
Something else to worry about is the digital election, in which people vote
for political candidates electronically via a polling system made secure by
encryption. The British government seems keen on this idea but the potential for
fraud is unbelievable. If we get a national election network in Britain, then
under current policy GCHQ would be charged with securing it. Would you be
comfortable with a system where the outcome of the election was controlled by
the spooks? This already happens in Russia. Do we want it here?
What about information warfare?
Information warfare is not new, and terrorists aren鈥檛 the only culprits.
Governments have been doing it for decades. Look at GCHQ. They listen to
people鈥檚 telephone conversations, hack into their computer systems, jam their
radar. This is information warfare.
What鈥檚 the worst possible outcome of a cyber attack?
Suppose a Western power were to hack into Iran鈥檚 national grid. There could
be an electricity blackout for, say, three days. Several hundred people might
die, such as those on dialysis machines. Retaliation might be expected for the
simple reason that Iran is not in a position to try the head of a Western state
for deliberately targeting civilians, which is a war crime. Unfortunately, this
view is not shared in places like Britain鈥檚 Ministry of Defence. Those engaged
in information warfare tend to view such attacks on other countries as being a
zero-cost way of conducting warfare.
If information warfare is so easy, doesn鈥檛 it make countries like Britain
or the US more vulnerable to attack?
Absolutely鈥攚e have more critical information technology and therefore
more to lose than countries such as Iran or Serbia. But the phrase 鈥渋nformation
warfare鈥� is also a marketing exercise by the intelligence community, who鈥檝e
talked it up to justify increased budgets, and redefined it to include threats
to infrastructure and even spin-doctoring. This has a certain appeal to the
current generation of politicians.
Could information warfare ever replace conventional wars?
I don鈥檛 think so. Take the recent NATO action in former Yugoslavia. A team in
Serbia attacked the NATO website by overloading it with requests for
information. They sent so many requests that the NATO Web server couldn鈥檛
provide information to anyone else. NATO鈥檚 response was to bomb the Serbian
satellite link and thus reduce the Serbian bandwidth to a level that NATO could
cope with. So information warfare is more likely to feed into conventional
warfare than replace it.
Would you refuse admission to a research student from a country that the
British authorities regard as 鈥渟ensitive鈥�?
The Foreign Office would like universities to vet students for
high-technology courses from certain countries. The leading research
universities and the Committee of Vice-Chancellors and Principals view this as
unacceptable. We haven鈥檛 turned people down because they are backed by a
government with which some people might not agree. If there鈥檚 going to be
vetting, it has to be done during the visa process.
Intelligence agencies have long tried to prevent encryption technologies
from spreading. Why are you so opposed to export controls?
The UK government is currently encouraging the European Commission to
introduce regulation designed to compel member states to license the export of
encryption software because of the perceived threat to security.
But encryption software has been available for years on the Net: the stable
door is already open. If this became law, it could make it more difficult to
sell software to Belgium than to sell electroshock rods to Indonesia.
Worse, because the proposed regulation is not limited to encryption but
affects everything the Ministry of Defence considers 鈥渉igh-tech鈥� it could
prevent researchers from sharing a wide range of other types of softwares,
information and training skills. We鈥檇 have to keep track of what we taught to
whom: we might have to get personal export licences to teach most of our foreign
students. It鈥檚 true that the US government also tried to control the export of
technologies and information related to encryption. But American university
researchers have freedom of speech rights which UK academics don鈥檛 have, so the
rules are not so intolerable for them.