Zimmermann's Senate testimony

[Philip Zimmermann <prz@ACM.ORG>]

Testimony of Philip R. Zimmermann to
the Subcommittee on Science, Technology, and Space
of the US Senate Committee on Commerce, Science, and 
Transportation
26 June 1996


Mr. Chairman and members of the committee, my name is Philip 
Zimmermann, and I'm Chairman and Chief Technology Officer for PGP 
Inc, a newly-formed company that provides cryptographic products.  
I'm here to talk to you today about S.1726 and the need to change 
US export control policy for cryptographic software.  I want to 
thank you for the opportunity to be here to speak in favor of this 
bill.

I'm the creator of PGP (Pretty Good Privacy), a public-key 
encryption software package for the protection of electronic mail.  
Since PGP was published domestically as freeware in June of 1991, 
it has spread organically all over the world, and has since become 
the de facto worldwide standard for encryption of E-mail, winning 
numerous industry awards along the way.  For three years I was the 
target of a criminal investigation by the US Customs Service, who 
assumed that laws were broken when PGP spread outside the US.  
That investigation was closed without indictment in January 1996.



Computers were developed in secret back in World War II mainly to 
break codes.  Ordinary people did not have access to computers, 
because they were few in number and too expensive.  Some people 
postulated that there would never be a need for more than half a 
dozen computers in the country, and assumed that ordinary people 
would never have a need for computers.  Some of the government's 
attitude toward cryptography today were formed in that period, and 
mirrors the old attitudes toward computers.  Why would ordinary 
people need to have access to good cryptography?

In addition to the limited availability of computers, another 
problem with cryptography in those days was that cryptographic 
keys had to be distributed over secure channels so that both 
parties could send encrypted traffic over insecure channels. 
Governments solved that problem by dispatching key couriers with 
satchels handcuffed to their wrists.  Governments could afford to 
send guys like these to their embassies overseas.  But the great 
masses of ordinary people would never have access to practical 
cryptography if keys had to be distributed this way.  No matter 
how cheap and powerful personal computers might someday become, 
you just can't send the keys electronically without the risk of 
interception. This widened the feasibility gap between government 
and personal access to cryptography.

Today, we live in a new world that has had two major breakthroughs 
that have an impact on this state of affairs.  The first is the 
coming of the personal computer and the information age.  The 
second breakthrough is public-key cryptography. 

With the first breakthrough comes cheap ubiquitous personal 
computers, modems, FAX machines, the Internet, E-mail, the World-
Wide Web, digital cellular phones, personal digital assistants 
(PDAs), wireless digital networks, ISDN, cable TV, and the data 
superhighway.  This information revolution is catalyzing the 
emergence of a global economy.

But this renaissance in electronic digital communication brings 
with it a disturbing erosion of our privacy.  In the past, if the 
government wanted to violate the privacy of ordinary citizens, it 
had to expend a certain amount of effort to intercept and steam 
open and read paper mail, and listen to and possibly transcribe 
spoken telephone conversation.  This is analogous to catching fish 
with a hook and a line, one fish at a time.  Fortunately for 
freedom and democracy, this kind of labor-intensive monitoring is 
not practical on a large scale.

Today, electronic mail is gradually replacing conventional paper 
mail, and is soon to be the norm for everyone, not the novelty it 
is today.  Unlike paper mail, E-mail messages are just too easy to 
intercept and scan for interesting keywords.  This can be done 
easily, routinely, automatically, and undetectably on a grand 
scale. This is analogous to driftnet fishing-- making a 
quantitative and qualitative Orwellian difference to the health of 
democracy.

The second breakthrough came in the late 1970s, with the 
mathematics of public key cryptography.  This allows people to 
communicate securely and conveniently with people they've never 
met, with no prior exchange of keys over secure channels.  No more 
special key couriers with black bags.  This, coupled with the 
trappings of the information age, means the great masses of people 
can at last use cryptography.  This new technology also provides 
digital signatures to authenticate transactions and messages, and 
allows for digital money, with all the implications that has for 
an electronic digital economy.  (See appendix)

This convergence of technology-- cheap ubiquitous PCs, modems, 
FAX, digital phones, information superhighways, et cetera-- is all 
part of the information revolution.  Encryption is just simple 
arithmetic to all this digital hardware.  All these devices will 
be using encryption.  The rest of the world uses it, and they 
laugh at the US because we are railing against nature, trying to 
stop it.  Trying to stop this is like trying to legislate the 
tides and the weather. It's like the buggy whip manufacturers 
trying to stop the cars-- even with the NSA and the FBI on their 
side, it's still impossible.  The information revolution is good 
for democracy-- good for a free market and trade. It contributed 
to the fall of the Soviet empire.  They couldn't stop it either.

Today, every off-the-shelf multimedia PC can become a secure voice 
telephone, through the use of freely available software such as 
PGPfone.  When you combine that with the strong political will 
that exists in the American people to have their privacy, it's 
going to require extreme measures to control this technology.  
What does this mean for the government's Clipper chip and key 
escrow systems?

Like every new technology, this comes at some cost.  Cars pollute 
the air and cause traffic jams.  Cryptography can help criminals 
hide their activities.  People in the law enforcement and 
intelligence communities are going to look at this only in their 
own terms.  But even with these costs, we still can't stop this 
from happening in a free market global economy.  Most people I 
talk to outside of government feel that the net result of 
providing privacy will be positive.

Law enforcement and intelligence interests in the government have 
attempted many times to suppress the availability of strong 
domestic encryption technology.  

In 1991, Senate Bill 266 included a non-binding resolution, which 
if it had become real law, would have forced manufacturers of 
secure communications equipment to insert special "trap doors" in 
their products, so that the government could read anyone's 
encrypted messages.  Before that measure was defeated, I wrote and 
released Pretty Good Privacy.  I did it because I wanted 
cryptography to be made available to the American public before it 
became illegal to use it.  I gave it away for free so that it 
would achieve wide dispersal, to inoculate the body politic.

The 1994 Digital Telephony bill mandated that phone companies 
install remote wiretapping ports into their central office digital 
switches, creating a new technology infrastructure for "point-and-
click" wiretapping, so that federal agents no longer have to go 
out and attach alligator clips to phone lines.  Now they'll be 
able to sit in their headquarters in Washington and listen in to 
your phone calls.  Of course, the law still requires a court order 
for a wiretap.  But while technology infrastructures tend to 
persist for generations, laws and policies can change overnight.  
Once a communications infrastructure optimized for surveillance 
becomes entrenched, a shift in political conditions may lead to 
abuse of this new-found power.  Political conditions may shift 
with the election of a new government, or perhaps more abruptly 
from the bombing of a Federal building.

A year after the 1994 Digital Telephony bill passed, the FBI 
disclosed plans to require the phone companies to build into their 
infrastructure the capacity to simultaneously wiretap one percent 
of all phone calls in all major US cities.  This would represent 
more than a thousandfold increase over previous levels in the 
number of phones that could be wiretapped.  In previous years, 
there were only about 1000 court-ordered wiretaps in the US per 
year, at the federal, state, and local levels combined.  It's hard 
to see how the government could even employ enough judges to sign 
enough wiretap orders to wiretap 1% of all our phone calls, much 
less hire enough federal agents to sit and listen to all that 
traffic in real time.  The only plausible way of processing that 
amount of traffic is a massive Orwellian application of automated 
voice recognition technology to sift through it all, searching for 
interesting keywords or searching for a particular speaker's 
voice.  If the government doesn't find the target in the first 1% 
sample, the wiretaps can be shifted over to a different 1% until 
the target is found, or until everyone's phone line has been 
checked for subversive traffic.  The FBI says they need this 
capacity to plan for the future.  This plan sparked such outrage 
that it was defeated in Congress, at least this time around, in 
1995.  But the mere fact that the FBI even asked for these broad 
powers is revealing of their agenda.  And the defeat of this plan 
isn't so reassuring when you consider that the 1994 Digital 
Telephony bill was also defeated the first time it was introduced, 
in 1993.  

Advances in technology will not permit the maintenance of the 
status quo, as far as privacy is concerned.  The status quo is 
unstable.  If we do nothing, new technologies will give the 
government new automatic surveillance capabilities that Stalin 
could never have dreamed of.  The only way to hold the line on 
privacy in the information age is strong cryptography.  
Cryptography strong enough to keep out major governments.

The government has a track record that does not inspire confidence 
that they will never abuse our civil liberties.  The FBI's 
COINTELPRO program targeted groups that opposed government 
policies.  They spied on the anti-war movement and the civil 
rights movement.  They wiretapped Martin Luther King's phone.  
Nixon had his enemies list.  And then there was the Watergate 
mess.  The War on Drugs has given America the world's largest per-
capita incarceration rate in the world, a distinction formerly 
held by South Africa, before we surpassed them during the eighties 
even when apartheid was in full swing.  Recently, we've seen the 
images and sounds of the Rodney King beatings, Detective Mark 
Fuhrman's tapes boasting of police abuses, and the disturbing 
events of the Ruby Ridge case.  And now Congress and the Clinton 
administration seem intent on passing laws curtailing our civil 
liberties on the Internet.  At no time in the past century has 
public distrust of the government been so broadly distributed 
across the political spectrum, as it is today.

The Clinton Administration seems to be attempting to deploy and 
entrench a communications infrastructure that would deny the 
citizenry the ability to protect its privacy.  This is unsettling 
because in a democracy, it is possible for bad people to 
occasionally get elected-- sometimes very bad people.  Normally, a 
well-functioning democracy has ways to remove these people from 
power.  But the wrong technology infrastructure could allow such a 
future government to watch every move anyone makes to oppose it.  
It could very well be the last government we ever elect.

When making public policy decisions about new technologies for the 
government, I think one should ask oneself which technologies 
would best strengthen the hand of a police state.  Then, do not 
allow the government to deploy those technologies.  This is simply 
a matter of good civic hygiene.



In addition to the human rights arguments, there are technological 
reasons why the current export control regime makes no sense 
anymore.

There has been considerable debate about allowing the export of 
implementations of the full 56-bit Data Encryption Standard (DES). 
At an academic cryptography conference in 1993, Michael Wiener of 
Northern Telecom in Ottawa presented a paper on how to crack the 
DES with a special machine.  He has fully designed and tested a 
chip that guesses DES keys at high speed until it finds the right 
one.  Although he has refrained from building the real chips so 
far, he can get these chips manufactured for $10.50 each, and can 
build 57000 of them into a special machine for $1 million that can 
try every DES key in 7 hours, averaging a solution in 3.5 hours.  
$1 million can be hidden in the budget of many companies.  For $10 
million, it takes 21 minutes to crack, and for $100 million, just 
two minutes.  That's full 56-bit DES, cracked in just two minutes.  
I'm sure the NSA can do it in seconds, with their budget.  This 
means that DES is now effectively dead for purposes of serious 
data security applications. If Congress acts now to enable the 
export of full DES products, it will be a day late and a dollar 
short.

Knowledge of cryptography is becoming so widespread, that export 
controls are no longer effective at controlling the spread of this 
technology.  People everywhere can and do write good cryptographic 
software, and we import it here but cannot export it, to the 
detriment of our indigenous software industry.

I wrote PGP from information in the open literature, putting it 
into a convenient package that everyone can use in a desktop or 
palmtop computer.  Then I gave it away for free, for the good of 
democracy.  This could have popped up anywhere, and spread.  Other 
people could have and would have done it.  And are doing it.  
Again and again.  All over the planet.  This technology belongs to 
everybody.


PGP has spread like a prairie fire, fanned by countless people who 
fervently want their privacy restored in the information age.

Today, human rights organizations are using PGP to protect their 
people overseas.  Amnesty International uses it.  The human rights 
group in the American Association for the Advancement of Science 
uses it.  It is used to protect witnesses who report human rights 
abuses in the Balkans, in Burma, in Guatemala, in Tibet.

Some Americans don't understand why I should be this concerned 
about the power of government.  But talking to people in Eastern 
Europe, you don't have to explain it to them.  They already get 
it-- and they don't understand why we don't.

I want to read you a quote from some E-mail I got in October 1993 
from someone in Latvia, on the day that Boris Yeltsin was shelling 
his Parliament building:  

"Phil I wish you to know: let it never be, but if 
dictatorship takes over Russia your PGP is widespread from Baltic 
to Far East now and will help democratic people if necessary.  
Thanks."



 Appendix -- How Public-Key Cryptography Works 

In conventional cryptosystems, such as the US Federal Data 
Encryption Standard (DES), a single key is used for both 
encryption and decryption.  This means that a key must be 
initially transmitted via secure channels so that both parties 
have it before encrypted messages can be sent over insecure 
channels.  This may be inconvenient.  If you have a secure channel 
for exchanging keys, then why do you need cryptography in the 
first place?

In public key cryptosystems, everyone has two related 
complementary keys, a publicly revealed key and a secret key.  
Each key unlocks the code that the other key makes.  Knowing the 
public key does not help you deduce the corresponding secret key.  
The public key can be published and widely disseminated across a 
communications network. This protocol provides privacy without the 
need for the same kind of secure channels that a conventional 
cryptosystem requires.

Anyone can use a recipient's public key to encrypt a message to 
that person, and that recipient uses her own corresponding secret 
key to decrypt that message.  No one but the recipient can decrypt 
it, because no one else has access to that secret key.  Not even 
the person who encrypted the message can decrypt it.  

Message authentication is also provided.  The sender's own secret 
key can be used to encrypt a message, thereby "signing" it.  This 
creates a digital signature of a message, which the recipient (or 
anyone else) can check by using the sender's public key to decrypt 
it.  This proves that the sender was the true originator of the 
message, and that the message has not been subsequently altered by 
anyone else, because the sender alone possesses the secret key 
that made that signature.  Forgery of a signed message is 
infeasible, and the sender cannot later disavow his signature. 

These two processes can be combined to provide both privacy and 
authentication by first signing a message with your own secret 
key, then encrypting the signed message with the recipient's 
public key. The recipient reverses these steps by first decrypting 
the message with her own secret key, then checking the enclosed 
signature with your public key.  These steps are done 
automatically by the recipient's software.



        Philip Zimmermann
        3021 11th Street
        Boulder, Colorado 80304
        303 541-0140
        E-mail:  prz@pgp.com