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<H1><A name="politics">History and politics of cryptography</A></H1>
<P>Cryptography has a long and interesting history, and has been the
subject of considerable political controversy.</P>
<H2><A name="intro.politics">Introduction</A></H2>
<H3><A NAME="26_1_1">History</A></H3>
<P>The classic book on the history of cryptography is David Kahn's<A href="biblio.html#Kahn">
The Codebreakers</A>. It traces codes and codebreaking from ancient
Egypt to the 20th century.</P>
<P>Diffie and Landau<A href="biblio.html#diffie"> Privacy on the Line:
The Politics of Wiretapping and Encryption</A> covers the history from
the First World War to the 1990s, with an emphasis on the US.</P>
<H4>World War II</H4>
<P>During the Second World War, the British "Ultra" project achieved one
of the greatest intelligence triumphs in the history of warfare,
breaking many Axis codes. One major target was the Enigma cipher
machine, a German device whose users were convinced it was unbreakable.
The American "Magic" project had some similar triumphs against Japanese
codes.</P>
<P>There are many books on this period. See our bibliography for
several. Two I particularly like are:</P>
<UL>
<LI>Andrew Hodges has done a superb<A href="http://www.turing.org.uk/book/">
biography</A> of Alan Turing, a key player among the Ultra
codebreakers. Turing was also an important computer pioneer. The terms<A
href="http://www.abelard.org/turpap/turpap.htm"> Turing test</A> and<A href="http://plato.stanford.edu/entries/turing-machine/">
Turing machine</A> are named for him, as is the<A href="http://www.acm.org">
ACM</A>'s highest technical<A href="http://www.acm.org/awards/taward.html">
award</A>.</LI>
<LI>Neal Stephenson's<A href="biblio.html#neal"> Cryptonomicon</A> is a
novel with cryptography central to the plot. Parts of it take place
during WW II, other parts today.</LI>
</UL>
<P>Bletchley Park, where much of the Ultra work was done, now has a
museum and a<A href="http://www.bletchleypark.org.uk/"> web site</A>.</P>
<P>The Ultra work introduced three major innovations.</P>
<UL>
<LI>The first break of Enigma was achieved by Polish Intelligence in
1931. Until then most code-breakers had been linguists, but a different
approach was needed to break machine ciphers. Polish Intelligence
recruited bright young mathematicians to crack the "unbreakable"
Enigma. When war came in 1939, the Poles told their allies about this,
putting Britain on the road to Ultra. The British also adopted a
mathematical approach.</LI>
<LI>Machines were extensively used in the attacks. First the Polish
"Bombe" for attacking Enigma, then British versions of it, then
machines such as Collosus for attacking other codes. By the end of the
war, some of these machines were beginning to closely resemble digital
computers. After the war, a team at Manchester University, several old
Ultra hands included, built one of the world's first actual
general-purpose digital computers.</LI>
<LI>Ultra made codebreaking a large-scale enterprise, producing
intelligence on an industrial scale. This was not a "black chamber",
not a hidden room in some obscure government building with a small crew
of code-breakers. The whole operation -- from wholesale interception of
enemy communications by stations around the world, through large-scale
code-breaking and analysis of the decrypted material (with an enormous
set of files for cross-referencing), to delivery of intelligence to
field commanders -- was huge, and very carefully managed.</LI>
</UL>
<P>So by the end of the war, Allied code-breakers were expert at
large-scale mechanised code-breaking. The payoffs were enormous.</P>
<H4><A name="postwar">Postwar and Cold War</A></H4>
<P>The wartime innovations were enthusiastically adopted by post-war and
Cold War signals intelligence agencies. Presumably many nations now
have some agency capable of sophisticated attacks on communications
security, and quite a few engage in such activity on a large scale.</P>
<P>America's<A href="glossary.html#NSA"> NSA</A>, for example, is said
to be both the world's largest employer of mathematicians and the
world's largest purchaser of computer equipment. Such claims may be
somewhat exaggerated, but beyond doubt the NSA -- and similar agencies
in other countries -- have some excellent mathematicians, lots of
powerful computers, sophisticated software, and the organisation and
funding to apply them on a large scale. Details of the NSA budget are
secret, but there are some published<A href="http://www.fas.org/irp/nsa/nsabudget.html">
estimates</A>.</P>
<P>Changes in the world's communications systems since WW II have
provided these agencies with new targets. Cracking the codes used on an
enemy's military or diplomatic communications has been common practice
for centuries. Extensive use of radio in war made large-scale attacks
such as Ultra possible. Modern communications make it possible to go
far beyond that. Consider listening in on cell phones, or intercepting
electronic mail, or tapping into the huge volumes of data on new media
such as fiber optics or satellite links. None of these targets existed
in 1950. All of them can be attacked today, and almost certainly are
being attacked.</P>
<P>The Ultra story was not made public until the 1970s. Much of the
recent history of codes and code-breaking has not been made public, and
some of it may never be. Two important books are:</P>
<UL>
<LI>Bamford's<A href="biblio.html#puzzle"> The Puzzle Palace</A>, a
history of the NSA</LI>
<LI>Hager's<A href="http://www.fas.org/irp/eprint/sp/index.html"> Secret
Power</A>, about the<A href="http://sg.yahoo.com/government/intelligence/echelon_network/">
Echelon</A> system -- the US, UK, Canada, Australia and New Zealand
co-operating to monitor much of the world's communications.</LI>
</UL>
<P>Note that these books cover only part of what is actually going on,
and then only the activities of nations open and democratic enough that
(some of) what they are doing can be discovered. A full picture,
including:</P>
<UL>
<LI>actions of the English-speaking democracies not covered in those
books</LI>
<LI>actions of other more-or-less sane governments</LI>
<LI>the activities of various more-or-less insane governments</LI>
<LI>possibilities for unauthorized action by government employees</LI>
<LI>possible actions by large non-government organisations:
corporations, criminals, or conspiracies</LI>
</UL>
<P>might be really frightening.</P>
<H4><A name="recent">Recent history -- the crypto wars</A></H4>
<P>Until quite recently, cryptography was primarily a concern of
governments, especially of the military, of spies, and of diplomats.
Much of it was extremely secret.</P>
<P>In recent years, that has changed a great deal. With computers and
networking becoming ubiquitous, cryptography is now important to almost
everyone. Among the developments since the 1970s:</P>
<UL>
<LI>The US gov't established the Data Encryption Standard,<A href="glossary.html#DES">
DES</A>, a<A href="glossary.html#block"> block cipher</A> for
cryptographic protection of unclassfied documents.</LI>
<LI>DES also became widely used in industry, especially regulated
industries such as banking.</LI>
<LI>Other nations produced their own standards, such as<A href="glossary.html#GOST">
GOST</A> in the Soviet Union.</LI>
<LI><A href="glossary.html#public">Public key</A> cryptography was
invented by Diffie and Hellman.</LI>
<LI>Academic conferences such as<A href="http://www-cse.ucsd.edu/users/mihir/crypto2k.html">
Crypto</A> and<A href="http://www.esat.kuleuven.ac.be/cosic/eurocrypt2000/">
Eurocrypt</A> began.</LI>
<LI>Several companies began offerring cryptographic products:<A href="glossary.html#RSAco">
RSA</A>,<A href="glossary.html#PGPI"> PGP</A>, the many vendors with<A href="glossary.html#PKI">
PKI</A> products, ...</LI>
<LI>Cryptography appeared in other products: operating systems, word
processors, ...</LI>
<LI>Network protocols based on crypto were developed:<A href="glossary.html#SSH">
SSH</A>,<A href="glossary.html#SSL"> SSL</A>,<A href="glossary.html#IPsec">
IPsec</A>, ...</LI>
<LI>Crytography came into widespread use to secure bank cards,
terminals, ...</LI>
<LI>The US government replaced<A href="glossary.html#DES"> DES</A> with
the much stronger Advanced Encryption Standard,<A href="glossary.html#AES">
AES</A></LI>
</UL>
<P>This has led to a complex ongoing battle between various mainly
government groups wanting to control the spread of crypto and various
others, notably the computer industry and the<A href="http://online.offshore.com.ai/security/">
cypherpunk</A> crypto advocates, wanting to encourage widespread use.</P>
<P>Steven Levy has written a fine history of much of this, called<A href="biblio.html#crypto">
Crypto: How the Code rebels Beat the Government -- Saving Privacy in
the Digital Age</A>.</P>
<P>The FreeS/WAN project is to a large extent an outgrowth of cypherpunk
ideas. Our reasons for doing the project can be seen in these quotes
from the<A href="http://www.eff.org/pub/Privacy/Crypto_misc/cypherpunk.manifesto">
Cypherpunk Manifesto</A>:</P>
<BLOCKQUOTE> Privacy is necessary for an open society in the electronic
age. ...
<P>We cannot expect governments, corporations, or other large, faceless
organizations to grant us privacy out of their beneficence. It is to
their advantage to speak of us, and we should expect that they will
speak. ...</P>
<P>We must defend our own privacy if we expect to have any. ...</P>
<P>Cypherpunks write code. We know that someone has to write software to
defend privacy, and since we can't get privacy unless we all do, we're
going to write it. We publish our code so that our fellow Cypherpunks
may practice and play with it. Our code is free for all to use,
worldwide. We don't much care if you don't approve of the software we
write. We know that software can't be destroyed and that a widely
dispersed system can't be shut down.</P>
<P>Cypherpunks deplore regulations on cryptography, for encryption is
fundamentally a private act. ...</P>
<P>For privacy to be widespread it must be part of a social contract.
People must come and together deploy these systems for the common good.
...</P>
</BLOCKQUOTE>
<P>To quote project leader John Gilmore:</P>
<BLOCKQUOTE> We are literally in a race between our ability to build and
deploy technology, and their ability to build and deploy laws and
treaties. Neither side is likely to back down or wise up until it has
definitively lost the race.</BLOCKQUOTE>
<P>If FreeS/WAN reaches its goal of making<A href="intro.html#opp.intro">
opportunistic encryption</A> widespread so that secure communication
can become the default for a large part of the net, we will have struck
a major blow.</P>
<H3><A name="intro.poli">Politics</A></H3>
<P>The political problem is that nearly all governments want to monitor
their enemies' communications, and some want to monitor their citizens.
They may be very interested in protecting some of their own
communications, and often some types of business communication, but not
in having everyone able to communicate securely. They therefore attempt
to restrict availability of strong cryptography as much as possible.</P>
<P>Things various governments have tried or are trying include:</P>
<UL>
<LI>Echelon, a monitor-the-world project of the US, UK, NZ, Australian
and Canadian<A href="glossary.html#SIGINT"> signals intelligence</A>
agencies. See this<A href="http://sg.yahoo.com/government/intelligence/echelon_network/">
collection</A> of links and this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2640682,00.html">
story</A> on the French Parliament's reaction.</LI>
<LI>Others governments may well have their own Echelon-like projects. To
quote the Dutch Minister of Defense, as reported in a German<A href="http://www.heise.de/tp/english/inhalt/te/4729/1.html">
magazine</A>:<BLOCKQUOTE> The government believes not only the
governments associated with Echelon are able to intercept communication
systems, but that it is an activity of the investigative authorities
and intelligence services of many countries with governments of
different political signature.</BLOCKQUOTE> Even if they have nothing
on the scale of Echelon, most intelligence agencies and police forces
certainly have some interception capability.</LI>
<LI><A href="glossary.html#NSA">NSA</A> tapping of submarine
communication cables, described in<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2764372,00.html">
this article</A></LI>
<LI>A proposal for international co-operation on<A href="http://www.heise.de/tp/english/special/enfo/4306/1.html">
Internet surveillance</A>.</LI>
<LI>Alleged<A href="http://cryptome.org/nsa-sabotage.htm"> sabotage</A>
of security products by the<A href="glossary.html#NSA"> NSA</A> (the US
signals intelligence agency).</LI>
<LI>The German armed forces and some government departments will stop
using American software for fear of NSA "back doors", according to this<A
href="http://www.theregister.co.uk/content/4/17679.html"> news story</A>
.</LI>
<LI>The British Regulation of Investigatory Powers bill. See this<A href="http://www.fipr.org/rip/index.html">
web page.</A> and perhaps this<A href="http://ars.userfriendly.org/cartoons/?id=20000806&mode=classic">
cartoon</A>.</LI>
<LI>A Russian<A href="http://www.eff.org/pub/Privacy/Foreign_and_local/Russia/russian_crypto_ban_english.edict">
ban</A> on cryptography</LI>
<LI>Chinese<A href="http://www.eff.org/pub/Misc/Publications/Declan_McCullagh/www/global/china">
controls</A> on net use.</LI>
<LI>The FBI's carnivore system for covert searches of email. See this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2601502,00.html">
news coverage</A> and this<A href="http://www.crypto.com/papers/carnivore-risks.html">
risk assessment</A>. The government had an external review of some
aspects of this system done. See this<A href="http://www.crypto.com/papers/carnivore_report_comments.html">
analysis</A> of that review. Possible defenses against Carnivore
include:
<UL>
<LI><A href="glossary.html#PGP">PGP</A> for end-to-end mail encryption</LI>
<LI><A href="http://www.home.aone.net.au/qualcomm/">secure sendmail</A>
for server-to-server encryption</LI>
<LI>IPsec encryption on the underlying IP network</LI>
</UL>
</LI>
<LI>export laws restricting strong cryptography as a munition. See<A href="#exlaw">
discussion</A> below.</LI>
<LI>various attempts to convince people that fundamentally flawed
cryptography, such as encryption with a<A href="#escrow"> back door</A>
for government access to data or with<A href="#shortkeys"> inadequate
key lengths</A>, was adequate for their needs.</LI>
</UL>
<P>Of course governments are by no means the only threat to privacy and
security on the net. Other threats include:</P>
<UL>
<LI>industrial espionage, as for example in this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2626931,00.html">
news story</A></LI>
<LI>attacks by organised criminals, as in this<A href="http://www.sans.org/newlook/alerts/NTE-bank.htm">
large-scale attack</A></LI>
<LI>collection of personal data by various companies.
<UL>
<LI>for example, consider the various corporate winners of Privacy
International's<A href="http://www.privacyinternational.org/bigbrother/">
Big Brother Awards</A>.</LI>
<LI><A href="http://www.zeroknowledge.com">Zero Knowledge</A> sell tools
to defend against this</LI>
</UL>
</LI>
<LI>individuals may also be a threat in a variety of ways and for a
variety of reasons</LI>
<LI>in particular, an individual with access to government or industry
data collections could do considerable damage using that data in
unauthorized ways.</LI>
</UL>
<P>One<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2640674,00.html">
study</A> enumerates threats and possible responses for small and
medium businesses. VPNs are a key part of the suggested strategy.</P>
<P>We consider privacy a human right. See the UN's<A href="http://www.un.org/Overview/rights.html">
Universal Declaration of Human Rights</A>, article twelve:</P>
<BLOCKQUOTE> No one shall be subjected to arbitrary interference with
his privacy, family, home or correspondence, nor to attacks upon his
honor and reputation. Everyone has the right to the protection of the
law against such interference or attacks.</BLOCKQUOTE>
<P>Our objective is to help make privacy possible on the Internet using
cryptography strong enough not even those well-funded government
agencies are likely to break it. If we can do that, the chances of
anyone else breaking it are negliible.</P>
<H3><A NAME="26_1_3">Links</A></H3>
<P>Many groups are working in different ways to defend privacy on the
net and elsewhere. Please consider contributing to one or more of these
groups:</P>
<UL>
<LI>the EFF's<A href="http://www.eff.org/crypto/"> Privacy Now!</A>
campaign</LI>
<LI>the<A href="http://www.gilc.org"> Global Internet Liberty Campaign</A>
</LI>
<LI><A href="http://www.cpsr.org/program/privacy/privacy.html">Computer
Professionals for Social Responsibility</A></LI>
</UL>
<P>For more on these issues see:</P>
<UL>
<LI>Steven Levy (Newsweek's chief technology writer and author of the
classic "Hackers") new book<A href="biblio.html#crypto"> Crypto: How
the Code Rebels Beat the Government--Saving Privacy in the Digital Age</A>
</LI>
<LI>Simson Garfinkel (Boston Globe columnist and author of books on<A href="biblio.html#PGP">
PGP</A> and<A href="biblio.html#practical"> Unix Security</A>) book<A href="biblio.html#Garfinkel">
Database Nation: the death of privacy in the 21st century</A></LI>
</UL>
<P>There are several collections of<A href="web.html#quotes"> crypto
quotes</A> on the net.</P>
<P>See also the<A href="biblio.html"> bibliography</A> and our list of<A href="web.html#policy">
web references</A> on cryptography law and policy.</P>
<H3><A NAME="26_1_4">Outline of this section</A></H3>
<P>The remainder of this section includes two pieces of writing by our
project leader</P>
<UL>
<LI>his<A href="#gilmore"> rationale</A> for starting this</LI>
<LI>another<A href="#policestate"> discussion</A> of project goals</LI>
</UL>
<P>and discussions of:</P>
<UL>
<LI><A href="#desnotsecure">why we do not use DES</A></LI>
<LI><A href="#exlaw">cryptography export laws</A></LI>
<LI>why<A href="#escrow"> government access to keys</A> is not a good
idea</LI>
<LI>the myth that<A href="#shortkeys"> short keys</A> are adequate for
some security requirements</LI>
</UL>
<P>and a section on<A href="#press"> press coverage of FreeS/WAN</A>.</P>
<H2><A name="leader">From our project leader</A></H2>
<P>FreeS/WAN project founder John Gilmore wrote a web page about why we
are doing this. The version below is slightly edited, to fit this
format and to update some links. For a version without these edits, see
his<A href="http://www.toad.com/gnu/"> home page</A>.</P>
<CENTER>
<H3><A name="gilmore">Swan: Securing the Internet against Wiretapping</A>
</H3>
</CENTER>
<P>My project for 1996 was to<B> secure 5% of the Internet traffic
against passive wiretapping</B>. It didn't happen in 1996, so I'm still
working on it in 1997, 1998, and 1999! If we get 5% in 1999 or 2000, we
can secure 20% the next year, against both active and passive attacks;
and 80% the following year. Soon the whole Internet will be private and
secure. The project is called S/WAN or S/Wan or Swan for Secure Wide
Area Network; since it's free software, we call it FreeSwan to
distinguish it from various commercial implementations.<A href="http://www.rsa.com/rsa/SWAN/">
RSA</A> came up with the term "S/WAN". Our main web site is at<A href="http://www.freeswan.org/">
http://www.freeswan.org/</A>. Want to help?</P>
<P>The idea is to deploy PC-based boxes that will sit between your local
area network and the Internet (near your firewall or router) which
opportunistically encrypt your Internet packets. Whenever you talk to a
machine (like a Web site) that doesn't support encryption, your traffic
goes out "in the clear" as usual. Whenever you connect to a machine
that does support this kind of encryption, this box automatically
encrypts all your packets, and decrypts the ones that come in. In
effect, each packet gets put into an "envelope" on one side of the net,
and removed from the envelope when it reaches its destination. This
works for all kinds of Internet traffic, including Web access, Telnet,
FTP, email, IRC, Usenet, etc.</P>
<P>The encryption boxes are standard PC's that use freely available
Linux software that you can download over the Internet or install from
a cheap CDROM.</P>
<P>This wasn't just my idea; lots of people have been working on it for
years. The encryption protocols for these boxes are called<A href="glossary.html#IPsec">
IPSEC (IP Security)</A>. They have been developed by the<A href="http://www.ietf.cnri.reston.va.us/html.charters/ipsec-charter.html">
IP Security Working Group</A> of the<A href="http://www.ietf.org/">
Internet Engineering Task Force</A>, and will be a standard part of the
next major version of the Internet protocols (<A href="http://playground.sun.com/pub/ipng/html/ipng-main.html">
IPv6</A>). For today's (IP version 4) Internet, they are an option.</P>
<P>The<A href="http://www.iab.org/iab"> Internet Architecture Board</A>
and<A href="http://www.ietf.org/"> Internet Engineering Steering Group</A>
have taken a<A href="iab-iesg.stmt"> strong stand</A> that the Internet
should use powerful encryption to provide security and privacy. I think
these protocols are the best chance to do that, because they can be
deployed very easily, without changing your hardware or software or
retraining your users. They offer the best security we know how to
build, using the Triple-DES, RSA, and Diffie-Hellman algorithms.</P>
<P>This "opportunistic encryption box" offers the "fax effect". As each
person installs one for their own use, it becomes more valuable for
their neighbors to install one too, because there's one more person to
use it with. The software automatically notices each newly installed
box, and doesn't require a network administrator to reconfigure it.
Instead of "virtual private networks" we have a "REAL private network";
we add privacy to the real network instead of layering a
manually-maintained virtual network on top of an insecure Internet.</P>
<H4>Deployment of IPSEC</H4>
<P>The US government would like to control the deployment of IP Security
with its<A href="#exlaw"> crypto export laws</A>. This isn't a problem
for my effort, because the cryptographic work is happening outside the
United States. A foreign philanthropist, and others, have donated the
resources required to add these protocols to the Linux operating
system.<A href="http://www.linux.org/"> Linux</A> is a complete, freely
available operating system for IBM PC's and several kinds of
workstation, which is compatible with Unix. It was written by Linus
Torvalds, and is still maintained by a talented team of expert
programmers working all over the world and coordinating over the
Internet. Linux is distributed under the<A href="glossary.html#GPL">
GNU Public License</A>, which gives everyone the right to copy it,
improve it, give it to their friends, sell it commercially, or do just
about anything else with it, without paying anyone for the privilege.</P>
<P>Organizations that want to secure their network will be able to put
two Ethernet cards into an IBM PC, install Linux on it from a $30 CDROM
or by downloading it over the net, and plug it in between their
Ethernet and their Internet link or firewall. That's all they'll have
to do to encrypt their Internet traffic everywhere outside their own
local area network.</P>
<P>Travelers will be able to run Linux on their laptops, to secure their
connection back to their home network (and to everywhere else that they
connect to, such as customer sites). Anyone who runs Linux on a
standalone PC will also be able to secure their network connections,
without changing their application software or how they operate their
computer from day to day.</P>
<P>There will also be numerous commercially available firewalls that use
this technology.<A href="http://www.rsa.com/"> RSA Data Security</A> is
coordinating the<A href="http://www.rsa.com/rsa/SWAN"> S/Wan (Secure
Wide Area Network)</A> project among more than a dozen vendors who use
these protocols. There's a<A href="http://www.rsa.com/rsa/SWAN/swan_test.htm">
compatability chart</A> that shows which vendors have tested their
boxes against which other vendors to guarantee interoperatility.</P>
<P>Eventually it will also move into the operating systems and
networking protocol stacks of major vendors. This will probably take
longer, because those vendors will have to figure out what they want to
do about the export controls.</P>
<H4>Current status</H4>
<P>My initial goal of securing 5% of the net by Christmas '96 was not
met. It was an ambitious goal, and inspired me and others to work hard,
but was ultimately too ambitious. The protocols were in an early stage
of development, and needed a lot more protocol design before they could
be implemented. As of April 1999, we have released version 1.0 of the
software (<A href="ftp://ftp.xs4all.nl/freeswan/freeswan-1.0.tar.gz">
freeswan-1.0.tar.gz</A>), which is suitable for setting up Virtual
Private Networks using shared secrets for authentication. It does not
yet do opportunistic encryption, or use DNSSEC for authentication;
those features are coming in a future release.</P>
<DL>
<DT>Protocols</DT>
<DD>The low-level encrypted packet formats are defined. The system for
publishing keys and providing secure domain name service is defined.
The IP Security working group has settled on an NSA-sponsored protocol
for key agreement (called ISAKMP/Oakley), but it is still being worked
on, as the protocol and its documentation is too complex and
incomplete. There are prototype implementations of ISAKMP. The protocol
is not yet defined to enable opportunistic encryption or the use of
DNSSEC keys.</DD>
<DT>Linux Implementation</DT>
<DD>The Linux implementation has reached its first major release and is
ready for production use in manually-configured networks, using Linux
kernel version 2.0.36.</DD>
<DT>Domain Name System Security</DT>
<DD>There is now a release of BIND 8.2 that includes most DNS Security
features.
<P>The first prototype implementation of Domain Name System Security was
funded by<A href="glossary.html#DARPA"> DARPA</A> as part of their<A href="http://www.darpa.mil/ito/research/is/index.html">
Information Survivability program</A>.<A href="http://www.tis.com">
Trusted Information Systems</A> wrote a modified version of<A href="http://www.isc.org/bind.html">
BIND</A>, the widely-used Berkeley implementation of the Domain Name
System.</P>
<P>TIS, ISC, and I merged the prototype into the standard version of
BIND. The first production version that supports KEY and SIG records is<B>
bind-4.9.5</B>. This or any later version of BIND will do for
publishing keys. It is available from the<A href="http://www.isc.org/bind.html">
Internet Software Consortium</A>. This version of BIND is not
export-controlled since it does not contain any cryptography. Later
releases starting with BIND 8.2 include cryptography for authenticating
DNS records, which is also exportable. Better documentation is needed.</P>
</DD>
</DL>
<H4>Why?</H4>
<P>Because I can. I have made enough money from several successful
startup companies, that for a while I don't have to work to support
myself. I spend my energies and money creating the kind of world that
I'd like to live in and that I'd like my (future) kids to live in.
Keeping and improving on the civil rights we have in the United States,
as we move more of our lives into cyberspace, is a particular goal of
mine.</P>
<H4>What You Can Do</H4>
<DL>
<DT>Install the latest BIND at your site.</DT>
<DD>You won't be able to publish any keys for your domain, until you
have upgraded your copy of BIND. The thing you really need from it is
the new version of<I> named</I>, the Name Daemon, which knows about the
new KEY and SIG record types. So, download it from the<A href="http://www.isc.org/bind.html">
Internet Software Consortium</A> and install it on your name server
machine (or get your system administrator, or Internet Service
Provider, to install it). Both your primary DNS site and all of your
secondary DNS sites will need the new release before you will be able
to publish your keys. You can tell which sites this is by running the
Unix command "dig MYDOMAIN ns" and seeing which sites are mentioned in
your NS (name server) records.</DD>
<DT>Set up a Linux system and run a 2.0.x kernel on it</DT>
<DD>Get a machine running Linux (say the 5.2 release from<A href="http://www.redhat.com">
Red Hat</A>). Give the machine two Ethernet cards.</DD>
<DT>Install the Linux IPSEC (Freeswan) software</DT>
<DD>If you're an experienced sysadmin or Linux hacker, install the
freeswan-1.0 release, or any later release or snapshot. These releases
do NOT provide automated "opportunistic" operation; they must be
manually configured for each site you wish to encrypt with.</DD>
<DT>Get on the linux-ipsec mailing list</DT>
<DD>The discussion forum for people working on the project, and testing
the code and documentation, is: linux-ipsec@clinet.fi. To join this
mailing list, send email to<A href="mailto:linux-ipsec-REQUEST@clinet.fi">
linux-ipsec-REQUEST@clinet.fi</A> containing a line of text that says
"subscribe linux-ipsec". (You can later get off the mailing list the
same way -- just send "unsubscribe linux-ipsec").</DD>
<P></P>
<DT>Check back at this web page every once in a while</DT>
<DD>I update this page periodically, and there may be new information in
it that you haven't seen. My intent is to send email to the mailing
list when I update the page in any significant way, so subscribing to
the list is an alternative.</DD>
</DL>
<P>Would you like to help? I can use people who are willing to write
documentation, install early releases for testing, write cryptographic
code outside the United States, sell pre-packaged software or systems
including this technology, and teach classes for network administrators
who want to install this technology. To offer to help, send me email at
gnu@toad.com. Tell me what country you live in and what your
citizenship is (it matters due to the export control laws; personally I
don't care). Include a copy of your resume and the URL of your home
page. Describe what you'd like to do for the project, and what you're
uniquely qualified for. Mention what other volunteer projects you've
been involved in (and how they worked out). Helping out will require
that you be able to commit to doing particular things, meet your
commitments, and be responsive by email. Volunteer projects just don't
work without those things.</P>
<H4>Related projects</H4>
<DL>
<DT>IPSEC for NetBSD</DT>
<DD>This prototype implementation of the IP Security protocols is for
another free operating system.<A href="ftp://ftp.funet.fi/pub/unix/security/net/ip/BSDipsec.tar.gz">
Download BSDipsec.tar.gz</A>.</DD>
<DT>IPSEC for<A href="http://www.openbsd.org"> OpenBSD</A></DT>
<DD>This prototype implementation of the IP Security protocols is for
yet another free operating system. It is directly integrated into the
OS release, since the OS is maintained in Canada, which has freedom of
speech in software.</DD>
</DL>
<H3><A name="policestate">Stopping wholesale monitoring</A></H3>
<P>From a message project leader John Gilmore posted to the mailing
list:</P>
<PRE>John Denker wrote:
> Indeed there are several ways in which the documentation overstates the
> scope of what this project does -- starting with the name
> FreeS/WAN. There's a big difference between having an encrypted IP tunnel
> versus having a Secure Wide-Area Network. This software does a fine job of
> the former, which is necessary but not sufficient for the latter.
The goal of the project is to make it very hard to tap your wide area
communications. The current system provides very good protection
against passive attacks (wiretapping and those big antenna farms).
Active attacks, which involve the intruder sending packets to your
system (like packets that break into sendmail and give them a root
shell :-) are much harder to guard against. Active attacks that
involve sending people (breaking into your house and replacing parts
of your computer with ones that transmit what you're doing) are also
much harder to guard against. Though we are putting effort into
protecting against active attacks, it's a much bigger job than merely
providing strong encryption. It involves general computer security,
and general physical security, which are two very expensive problems
for even a site to solve, let alone to build into a whole society.
The societal benefit of building an infrastructure that protects
well against passive attacks is that it makes it much harder to do
undetected bulk monitoring of the population. It's a defense against
police-states, not against policemen.
Policemen can put in the effort required to actively attack sites that
they have strong suspicions about. But police states won't be able to
build systems that automatically monitor everyone's communications.
Either they will be able to monitor only a small subset of the
populace (by targeting those who screwed up their passive security),
or their monitoring activities will be detectable by those monitored
(active attacks leave packet traces or footprints), which can then be
addressed through the press and through political means if they become
too widespread.
FreeS/WAN does not protect very well against traffic analysis, which
is a kind of widespread police-state style monitoring that still
reveals significant information (who's talking to who) without
revealing the contents of what was said. Defenses against traffic
analysis are an open research problem. Zero Knowledge Systems is
actively deploying a system designed to thwart it, designed by Ian
Goldberg. The jury is out on whether it actually works; a lot more
experience with it will be needed.</PRE>
<P>Notes on things mentioned in that message:</P>
<UL>
<LI>Denker is a co-author of a<A href="intro.html#applied"> paper</A> on
a large FreeS/WAN application.</LI>
<LI>Information on Zero Knowledge is on their<A href="http://www.zks.net/">
web site</A>. Their Freedom product, designed to provide untracable
pseudonyms for use on the net, is no longer marketed.</LI>
<LI>Another section of our documentation discusses ways to<A href="ipsec.html#traffic.resist">
resist traffic analysis</A>.</LI>
</UL>
<H2><A name="weak">Government promotion of weak crypto</A></H2>
<P>Various groups, especially governments and especially the US
government, have a long history of advocating various forms of bogus
security.</P>
<P>We regard bogus security as extremely dangerous. If users are
deceived into relying on bogus security, then they may be exposed to
large risks. They would be better off having no security and knowing
it. At least then they would be careful about what they said.</P>
<P><STRONG>Avoiding bogus security is a key design criterion for
everything we do in FreeS/WAN</STRONG>. The most conspicuous example is
our refusal to support<A href="#desnotsecure"> single DES</A>. Other
IPsec "features" which we do not implement are discussed in our<A href="compat.html#dropped">
compatibility</A> document.</P>
<H3><A name="escrow">Escrowed encryption</A></H3>
<P>Various governments have made persistent attempts to encourage or
mandate "escrowed encrytion", also called "key recovery", or GAK for
"government access to keys". The idea is that cryptographic keys be
held by some third party and turned over to law enforcement or security
agencies under some conditions.</P>
<PRE> Mary had a little key - she kept it in escrow,
and every thing that Mary said,
the feds were sure to know.</PRE>
<P>A<A href="web.html#quotes"> crypto quotes</A> page attributes this to<A
href="http://www.scramdisk.clara.net/"> Sam Simpson</A>.</P>
<P>There is an excellent paper available on<A href="http://www.cdt.org/crypto/risks98/">
Risks of Escrowed Encryption</A>, from a group of cryptographic
luminaries which included our project leader.</P>
<P>Like any unnecessary complication, GAK tends to weaken security of
any design it infects. For example:</P>
<UL>
<LI>Matt Blaze found a fatal flaw in the US government's Clipper chip
shortly after design information became public. See his paper "Protocol
Failure in the Escrowed Encryption Standard" on his<A href="http://www.crypto.com/papers/">
papers</A> page.</LI>
<LI>a rather<A href="http://www.pgp.com/other/advisories/adk.asp"> nasty
bug</A> was found in the "additional decryption keys" "feature" of some
releases of<A href="glossary.html#PGP"> PGP</A></LI>
</UL>
<P>FreeS/WAN does not support escrowed encryption, and never will.</P>
<H3><A name="shortkeys">Limited key lengths</A></H3>
<P>Various governments, and some vendors, have also made persistent
attempts to convince people that:</P>
<UL>
<LI>weak systems are sufficient for some data</LI>
<LI>strong cryptography should be reserved for cases where the extra
overheads are justified</LI>
</UL>
<P><STRONG>This is utter nonsense</STRONG>.</P>
<P>Weak systems touted include:</P>
<UL>
<LI>the ludicrously weak (deliberately crippled) 40-bit ciphers that
until recently were all various<A href="#exlaw"> export laws</A>
allowed</LI>
<LI>56-bit single DES, discussed<A href="#desnotsecure"> below</A></LI>
<LI>64-bit symmetric ciphers and 512-bit RSA, the maximums for
unrestricted export under various current laws</LI>
</UL>
<P>The notion that choice of ciphers or keysize should be determined by
a trade-off between security requirements and overheads is pure
bafflegab.</P>
<UL>
<LI>For most<A href="glossary.html#symmetric"> symmetric ciphers</A>, it
is simply a lie. Any block cipher has some natural maximum keysize
inherent in the design -- 128 bits for<A href="glossary.html#IDEA">
IDEA</A> or<A href="glossary.html#CAST128"> CAST-128</A>, 256 for
Serpent or Twofish, 448 for<A href="glossary.html#Blowfish"> Blowfish</A>
and 2048 for<A href="glossary.html#RC4"> RC4</A>. Using a key size
smaller than that limit gives<EM> exactly zero</EM> savings in
overhead. The crippled 40-bit or 64-bit version of the cipher provides<EM>
no advantage whatsoever</EM>.</LI>
<LI><A href="glossary.html#AES">AES</A> uses 10 rounds with 128-bit
keys, 12 rounds for 192-bit and 14 rounds for 256-bit, so there
actually is a small difference in overhead, but not enough to matter in
most applications.</LI>
<LI>For<A href="glossary.html#3DES"> triple DES</A> there is a grain of
truth in the argument. 3DES is indeed three times slower than single
DES. However, the solution is not to use the insecure single DES, but
to pick a faster secure cipher.<A href="glossary.html#CAST128">
CAST-128</A>,<A href="glossary.html#Blowfish"> Blowfish</A> and the<A href="glossary.html#AES">
AES candidate</A> ciphers are are all considerably faster in software
than DES (let alone 3DES!), and apparently secure.</LI>
<LI>For<A href="glossary.html#public"> public key</A> techniques, there
are extra overheads for larger keys, but they generally do not affect
overall performance significantly. Practical public key applications
are usually<A href="glossary.html#hybrid"> hybrid</A> systems in which
the bulk of the work is done by a symmetric cipher. The effect of
increasing the cost of the public key operations is typically
negligible because the public key operations use only a tiny fraction
of total resources.
<P>For example, suppose public key operations use use 1% of the time in
a hybrid system and you triple the cost of public key operations. The
cost of symmetric cipher operations is unchanged at 99% of the original
total cost, so the overall effect is a jump from 99 + 1 = 100 to 99 + 3
= 102, a 2% rise in system cost.</P>
</LI>
</UL>
<P>In short,<STRONG> there has never been any technical reason to use
inadequate ciphers</STRONG>. The only reason there has ever been for
anyone to use such ciphers is that government agencies want weak
ciphers used so that they can crack them. The alleged savings are
simply propaganda.</P>
<PRE> Mary had a little key (It's all she could export),
and all the email that she sent was opened at the Fort.</PRE>
<P>A<A href="web.html#quotes"> crypto quotes</A> page attributes this to<A
href="http://theory.lcs.mit.edu:80/~rivest/"> Ron Rivest</A>. NSA
headquarters is at Fort Meade, Maryland.</P>
<P>Our policy in FreeS/WAN is to use only cryptographic components with
adequate keylength and no known weaknesses.</P>
<UL>
<LI>We do not implement single DES because it is clearly<A href="#desnotsecure">
insecure</A>, so implemeting it would violate our policy of avoiding
bogus security. Our default cipher is<A href="glossary.html#3DES"> 3DES</A>
</LI>
<LI>Similarly, we do not implement the 768-bit Group 1 for<A href="glossary.html#DH">
Diffie-Hellman</A> key negotiation. We provide only the 1024-bit Group
2 and 1536-bit Group 5.</LI>
</UL>
<P>Detailed discussion of which IPsec features we implement or omit is
in out<A href="compat.html"> compatibility document</A>.</P>
<P>These decisions imply that we cannot fully conform to the IPsec RFCs,
since those have DES as the only required cipher and Group 1 as the
only required DH group. (In our view, the standards were subverted into
offerring bogus security.) Fortunately, we can still interoperate with
most other IPsec implementations since nearly all implementers provide
at least 3DES and Group 2 as well.</P>
<P>We hope that eventually the RFCs will catch up with our (and others')
current practice and reject dubious components. Some of our team and a
number of others are working on this in<A href="glossary.html#IETF">
IETF</A> working groups.</P>
<H4>Some real trade-offs</H4>
<P>Of course, making systems secure does involve costs, and trade-offs
can be made between cost and security. However, the real trade-offs
have nothing to do with using weaker ciphers.</P>
<P>There can be substantial hardware and software costs. There are often
substantial training costs, both to train administrators and to
increase user awareness of security issues and procedures. There are
almost always substantial staff or contracting costs.</P>
<P>Security takes staff time for planning, implementation, testing and
auditing. Some of the issues are subtle; you need good (hence often
expensive) people for this. You also need people to monitor your
systems and respond to problems. The best safe ever built is insecure
if an attacker can work on it for days without anyone noticing. Any
computer is insecure if the administrator is "too busy" to check the
logs.</P>
<P>Moreover, someone in your organisation (or on contract to it) needs
to spend considerable time keeping up with new developments. EvilDoers<EM>
will</EM> know about new attacks shortly after they are found. You need
to know about them before your systems are attacked. If your vendor
provides a patch, you need to apply it. If the vendor does nothing, you
need to complain or start looking for another vendor.</P>
<P>For a fairly awful example, see this<A href="http://www.sans.org/newlook/alerts/NTE-bank.htm">
report</A>. In that case over a million credit card numbers were taken
from e-commerce sites, using security flaws in Windows NT servers.
Microsoft had long since released patches for most or all of the flaws,
but the site administrators had not applied them.</P>
<P>At an absolute minimum, you must do something about such issues<EM>
before</EM> an exploitation tool is posted to the net for downloading
by dozens of "script kiddies". Such a tool might appear at any time
from the announcement of the security hole to several months later.
Once it appears, anyone with a browser and an attitude can break any
system whose administrators have done nothing about the flaw.</P>
<P>Compared to those costs, cipher overheads are an insignificant factor
in the cost of security.</P>
<P>The only thing using a weak cipher can do for you is to cause all
your other investment to be wasted.</P>
<H2><A name="exlaw">Cryptography Export Laws</A></H2>
<P>Many nations restrict the export of cryptography and some restrict
its use by their citizens or others within their borders.</P>
<H3><A name="USlaw">US Law</A></H3>
<P>US laws, as currently interpreted by the US government, forbid export
of most cryptographic software from the US in machine-readable form
without government permission. In general, the restrictions apply even
if the software is widely-disseminated or public-domain and even if it
came from outside the US originally. Cryptography is legally a munition
and export is tightly controlled under the<A href="glossary.html#EAR">
EAR</A> Export Administration Regulations.</P>
<P>If you are a US citizen, your brain is considered US territory no
matter where it is physically located at the moment. The US believes
that its laws apply to its citizens everywhere, not just within the US.
Providing technical assistance or advice to foreign "munitions"
projects is illegal. The US government has very little sense of humor
about this issue and does not consider good intentions to be sufficient
excuse. Beware.</P>
<P>The<A href="http://www.bxa.doc.gov/Encryption/"> official website</A>
for these regulations is run by the Commerce Department's Bureau of
Export Administration (BXA).</P>
<P>The<A href="http://www.eff.org/bernstein/"> Bernstein case</A>
challenges the export restrictions on Constitutional grounds. Code is
speech so restrictions on export of code violate the First Amendment's
free speech provisions. This argument has succeeded in two levels of
court so far. It is quite likely to go on to the Supreme Court.</P>
<P>The regulations were changed substantially in January 2000,
apparently as a government attempt to get off the hook in the Bernstein
case. It is now legal to export public domain source code for
encryption, provided you notify the<A href="glossary.html#BXA"> BXA</A>
.</P>
<P>There are, however, still restrictions in force. Moreover, the
regulations can still be changed again whenever the government chooses
to do so. Short of a Supreme Court ruling (in the Berstein case or
another) that overturns the regulations completely, the problem of
export regulation is not likely to go away in the forseeable future.</P>
<H4><A name="UScontrib">US contributions to FreeS/WAN</A></H4>
<P>The FreeS/WAN project<STRONG> cannot accept software contributions,<EM>
not even small bug fixes</EM>, from US citizens or residents</STRONG>.
We want it to be absolutely clear that our distribution is not subject
to US export law. Any contribution from an American might open that
question to a debate we'd prefer to avoid. It might also put the
contributor at serious legal risk.</P>
<P>Of course Americans can still make valuable contributions (many
already have) by reporting bugs, or otherwise contributing to
discussions, on the project<A href="mail.html"> mailing list</A>. Since
the list is public, this is clearly constitutionally protected free
speech.</P>
<P>Note, however, that the export laws restrict Americans from providing
technical assistance to foreign "munitions" projects. The government
might claim that private discussions or correspondence with FreeS/WAN
developers were covered by this. It is not clear what the courts would
do with such a claim, so we strongly encourage Americans to use the
list rather than risk the complications.</P>
<H3><A name="wrong">What's wrong with restrictions on cryptography</A></H3>
<P>Some quotes from prominent cryptography experts:</P>
<BLOCKQUOTE> The real aim of current policy is to ensure the continued
effectiveness of US information warfare assets against individuals,
businesses and governments in Europe and elsewhere.
<BR><A href="http://www.cl.cam.ac.uk/users/rja14"> Ross Anderson,
Cambridge University</A></BLOCKQUOTE><BLOCKQUOTE> If the government
were honest about its motives, then the debate about crypto export
policy would have ended years ago.
<BR><A href="http://www.counterpane.com"> Bruce Schneier, Counterpane
Systems</A></BLOCKQUOTE><BLOCKQUOTE> The NSA regularly lies to people
who ask it for advice on export control. They have no reason not to;
accomplishing their goal by any legal means is fine by them. Lying by
government employees is legal.
<BR> John Gilmore.</BLOCKQUOTE>
<P>The Internet Architecture Board (IAB) and the Internet Engineering
Steering Group (IESG) made a<A href="iab-iesg.stmt"> strong statement</A>
in favour of worldwide access to strong cryptography. Essentially the
same statement is in the appropriately numbered<A href="ftp://ftp.isi.edu/in-notes/rfc1984.txt">
RFC 1984</A>. Two critical paragraphs are:</P>
<BLOCKQUOTE> ... various governments have actual or proposed policies on
access to cryptographic technology ...
<P>(a) ... export controls ...
<BR> (b) ... short cryptographic keys ...
<BR> (c) ... keys should be in the hands of the government or ...
<BR> (d) prohibit the use of cryptology ...</P>
<P>We believe that such policies are against the interests of consumers
and the business community, are largely irrelevant to issues of
military security, and provide only a marginal or illusory benefit to
law enforcement agencies, ...</P>
<P>The IAB and IESG would like to encourage policies that allow ready
access to uniform strong cryptographic technology for all Internet
users in all countries.</P>
</BLOCKQUOTE>
<P>Our goal in the FreeS/WAN project is to build just such "strong
cryptographic technology" and to distribute it "for all Internet users
in all countries".</P>
<P>More recently, the same two bodies (IESG and IAB) have issued<A href="ftp://ftp.isi.edu/in-notes/rfc2804.txt">
RFC 2804</A> on why the IETF should not build wiretapping capabilities
into protocols for the convenience of security or law enforcement
agenicies. The abstract from that document is:</P>
<BLOCKQUOTE> The Internet Engineering Task Force (IETF) has been asked
to take a position on the inclusion into IETF standards-track documents
of functionality designed to facilitate wiretapping.
<P>This memo explains what the IETF thinks the question means, why its
answer is "no", and what that answer means.</P>
</BLOCKQUOTE> A quote from the debate leading up to that RFC:<BLOCKQUOTE>
We should not be building surveillance technology into standards. Law
enforcement was not supposed to be easy. Where it is easy, it's called
a police state.
<BR> Jeff Schiller of MIT, in a discussion of FBI demands for wiretap
capability on the net, as quoted by<A href="http://www.wired.com/news/politics/0,1283,31895,00.html">
Wired</A>.</BLOCKQUOTE>
<P>The<A href="http://www.ietf.org/mailman/listinfo/raven"> Raven</A>
mailing list was set up for this IETF discussion.</P>
<P>Our goal is to go beyond that RFC and prevent Internet wiretapping
entirely.</P>
<H3><A name="Wassenaar">The Wassenaar Arrangement</A></H3>
<P>Restrictions on the export of cryptography are not just US policy,
though some consider the US at least partly to blame for the policies
of other nations in this area.</P>
<P>A number of countries:</P>
<P>Argentina, Australia, Austria, Belgium, Bulgaria, Canada, Czech
Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland,
Italy, Japan, Luxembourg, Netherlands, New Zealand, Norway, Poland,
Portugal, Republic of Korea, Romania, Russian Federation, Slovak
Republic, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom
and United States</P>
<P>have signed the Wassenaar Arrangement which restricts export of
munitions and other tools of war. Cryptographic sofware is covered
there.</P>
<P>Wassenaar details are available from the<A href="http://www.wassenaar.org/">
Wassenaar Secretariat</A>, and elsewhere in a more readable<A href="http://www.fitug.de/news/wa/index.html">
HTML version</A>.</P>
<P>For a critique see the<A href="http://www.gilc.org/crypto/wassenaar">
GILC site</A>:</P>
<BLOCKQUOTE> The Global Internet Liberty Campaign (GILC) has begun a
campaign calling for the removal of cryptography controls from the
Wassenaar Arrangement.
<P>The aim of the Wassenaar Arrangement is to prevent the build up of
military capabilities that threaten regional and international security
and stability . . .</P>
<P>There is no sound basis within the Wassenaar Arrangement for the
continuation of any export controls on cryptographic products.</P>
</BLOCKQUOTE>
<P>We agree entirely.</P>
<P>An interesting analysis of Wassenaar can be found on the<A href="http://www.cyber-rights.org/crypto/wassenaar.htm">
cyber-rights.org</A> site.</P>
<H3><A name="status">Export status of Linux FreeS/WAN</A></H3>
<P>We believe our software is entirely exempt from these controls since
the Wassenaar<A href="http://www.wassenaar.org/list/GTN%20and%20GSN%20-%2099.pdf">
General Software Note</A> says:</P>
<BLOCKQUOTE> The Lists do not control "software" which is either:
<OL>
<LI>Generally available to the public by . . . retail . . . or</LI>
<LI>"In the public domain".</LI>
</OL>
</BLOCKQUOTE>
<P>There is a note restricting some of this, but it is a sub-heading
under point 1, so it appears not to apply to public domain software.</P>
<P>Their glossary defines "In the public domain" as:</P>
<BLOCKQUOTE> . . . "technology" or "software" which has been made
available without restrictions upon its further dissemination.
<P>N.B. Copyright restrictions do not remove "technology" or "software"
from being "in the public domain".</P>
</BLOCKQUOTE>
<P>We therefore believe that software freely distributed under the<A href="glossary.html#GPL">
GNU Public License</A>, such as Linux FreeS/WAN, is exempt from
Wassenaar restrictions.</P>
<P>Most of the development work is being done in Canada. Our
understanding is that the Canadian government accepts this
interpretation.</P>
<UL>
<LI>A web statement of<A href="http://www.dfait-maeci.gc.ca/~eicb/notices/ser113-e.htm">
Canadian policy</A> is available from the Department of Foreign Affairs
and International Trade.</LI>
<LI>Another document from that department states that<A href="http://www.dfait-maeci.gc.ca/~eicb/export/gr1_e.htm">
public domain software</A> is exempt from the export controls.</LI>
<LI>A researcher's<A href="http://insight.mcmaster.ca/org/efc/pages/doc/crypto-export.html">
analysis</A> of Canadian policy is also available.</LI>
</UL>
<P>Recent copies of the freely modifiable and distributable source code
exist in many countries. Citizens all over the world participate in its
use and evolution, and guard its ongoing distribution. Even if Canadian
policy were to change, the software would continue to evolve in
countries which do not restrict exports, and would continue to be
imported from there into unfree countries. "The Net culture treats
censorship as damage, and routes around it."</P>
<H3><A name="help">Help spread IPsec around</A></H3>
<P>You can help. If you don't know of a Linux FreeS/WAN archive in your
own country, please download it now to your personal machine, and
consider making it publicly accessible if that doesn't violate your own
laws. If you have the resources, consider going one step further and
setting up a mirror site for the whole<A href="intro.html#munitions">
munitions</A> Linux crypto software archive.</P>
<P>If you make Linux CD-ROMs, please consider including this code, in a
way that violates no laws (in a free country, or in a domestic-only CD
product).</P>
<P>Please send a note about any new archive mirror sites or CD
distributions to linux-ipsec@clinet.fi so we can update the
documentation.</P>
<P>Lists of current<A href="intro.html#sites"> mirror sites</A> and of<A href="intro.html#distwith">
distributions</A> which include FreeS/WAN are in our introduction
section.</P>
<H2><A name="desnotsecure">DES is Not Secure</A></H2>
<P>DES, the<STRONG> D</STRONG>ata<STRONG> E</STRONG>ncryption<STRONG> S</STRONG>
tandard, can no longer be considered secure. While no major flaws in its
innards are known, it is fundamentally inadequate because its<STRONG>
56-bit key is too short</STRONG>. It is vulnerable to<A href="glossary.html#brute">
brute-force search</A> of the whole key space, either by large
collections of general-purpose machines or even more quickly by
specialized hardware. Of course this also applies to<STRONG> any other
cipher with only a 56-bit key</STRONG>. The only reason anyone could
have for using a 56 or 64-bit key is to comply with various<A href="exportlaw.html">
export laws</A> intended to ensure the use of breakable ciphers.</P>
<P>Non-government cryptologists have been saying DES's 56-bit key was
too short for some time -- some of them were saying it in the 70's when
DES became a standard -- but the US government has consistently
ridiculed such suggestions.</P>
<P>A group of well-known cryptographers looked at key lengths in a<A href="http://www.counterpane.com/keylength.html">
1996 paper</A>. They suggested a<EM> minimum</EM> of 75 bits to
consider an existing cipher secure and a<EM> minimum of 90 bits for new
ciphers</EM>. More recent papers, covering both<A href="glossary.html#symmetric">
symmetric</A> and<A href="glossary.html#public"> public key</A> systems
are at<A href="http://www.cryptosavvy.com/"> cryptosavvy.com</A> and<A href="http://www.rsasecurity.com/rsalabs/bulletins/bulletin13.html">
rsa.com</A>. For all algorithms, the minimum keylengths recommended in
such papers are significantly longer than the maximums allowed by
various export laws.</P>
<P>In a<A href="http://www.privacy.nb.ca/cryptography/archives/cryptography/html/1998-09/0095.html">
1998 ruling</A>, a German court described DES as "out-of-date and not
safe enough" and held a bank liable for using it.</P>
<H3><A name="deshware">Dedicated hardware breaks DES in a few days</A></H3>
<P>The question of DES security has now been settled once and for all.
In early 1998, the<A href="http://www.eff.org/"> Electronic Frontier
Foundation</A> built a<A href="http://www.eff.org/descracker.html">
DES-cracking machine</A>. It can find a DES key in an average of a few
days' search. The details of all this, including complete code listings
and complete plans for the machine, have been published in<A href="biblio.html#EFF">
<CITE> Cracking DES</CITE></A>, by the Electronic Frontier Foundation.</P>
<P>That machine cost just over $200,000 to design and build. "Moore's
Law" is that machines get faster (or cheaper, for the same speed) by
roughly a factor of two every 18 months. At that rate, their $200,000
in 1998 becomes $50,000 in 2001.</P>
<P>However, Moore's Law is not exact and the $50,000 estimate does not
allow for the fact that a copy based on the published EFF design would
cost far less than the original. We cannot say exactly what such a
cracker would cost today, but it would likely be somewhere between
$10,000 and $100,000.</P>
<P>A large corporation could build one of these out of petty cash. The
cost is low enough for a senior manager to hide it in a departmental
budget and avoid having to announce or justify the project. Any
government agency, from a major municipal police force up, could afford
one. Or any other group with a respectable budget -- criminal
organisations, political groups, labour unions, religious groups, ...
Or any millionaire with an obsession or a grudge, or just strange taste
in toys.</P>
<P>One might wonder if a private security or detective agency would have
one for rent. They wouldn't need many clients to pay off that
investment.</P>
<H3><A name="spooks">Spooks may break DES faster yet</A></H3>
<P>As for the security and intelligence agencies of various nations,
they may have had DES crackers for years, and theirs may be much
faster. It is difficult to make most computer applications work well on
parallel machines, or to design specialised hardware to accelerate
them. Cipher-cracking is one of the very few exceptions. It is entirely
straightforward to speed up cracking by just adding hardware. Within
very broad limits, you can make it as fast as you like if you have the
budget. The EFF's $200,000 machine breaks DES in a few days. An<A href="http://www.planepage.com/">
aviation website</A> gives the cost of a B1 bomber as $200,000,000.
Spending that much, an intelligence agency could break DES in an
average time of<EM> six and a half minutes</EM>.</P>
<P>That estimate assumes they use the EFF's 1998 technology and just
spend more money. They may have an attack that is superior to brute
force, they quite likely have better chip technology (Moore's law, a
bigger budget, and whatever secret advances they may have made) and of
course they may have spent the price of an aircraft carrier, not just
one aircraft.</P>
<P>In short, we have<EM> no idea</EM> how quickly these organisations
can break DES. Unless they're spectacularly incompetent or horribly
underfunded, they can certainly break it, but we cannot guess how
quickly. Pick any time unit between days and milliseconds; none is
entirely unbelievable. More to the point, none of them is of any
comfort if you don't want such organisations reading your
communications.</P>
<P>Note that this may be a concern even if nothing you do is a threat to
anyone's national security. An intelligence agency might well consider
it to be in their national interest for certain companies to do well.
If you're competing against such companies in a world market and that
agency can read your secrets, you have a serious problem.</P>
<P>One might wonder about technology the former Soviet Union and its
allies developed for cracking DES during the Cold War. They must have
tried; the cipher was an American standard and widely used. Certainly
those countries have some fine mathematicians, and those agencies had
budget. How well did they succeed? Is their technology now for sale or
rent?</P>
<H3><A name="desnet">Networks break DES in a few weeks</A></H3>
<P>Before the definitive EFF effort, DES had been cracked several times
by people using many machines. See this<A href="http://www.distributed.net/pressroom/DESII-1-PR.html">
press release</A> for example.</P>
<P>A major corporation, university, or government department could break
DES by using spare cycles on their existing collection of computers, by
dedicating a group of otherwise surplus machines to the problem, or by
combining the two approaches. It might take them weeks or months,
rather than the days required for the EFF machine, but they could do
it.</P>
<P>What about someone working alone, without the resources of a large
organisation? For them, cracking DES will not be easy, but it may be
possible. A few thousand dollars buys a lot of surplus workstations. A
pile of such machines will certainly heat your garage nicely and might
break DES in a few months or years. Or enroll at a university and use
their machines. Or use an employer's machines. Or crack security
somewhere and steal the resources to crack a DES key. Or write a virus
that steals small amounts of resources on many machines. Or . . .</P>
<P>None of these approaches are easy or break DES really quickly, but an
attacker only needs to find one that is feasible and breaks DES quickly
enough to be dangerous. How much would you care to bet that this will
be impossible if the attacker is clever and determined? How valuable is
your data? Are you authorised to risk it on a dubious bet?</P>
<H3><A name="no_des">We disable DES</A></H3>
<P>In short, it is now absolutely clear that<STRONG> DES is not secure</STRONG>
against</P>
<UL>
<LI>any<STRONG> well-funded opponent</STRONG></LI>
<LI>any opponent (even a penniless one) with access (even stolen access)
to<STRONG> enough general purpose computers</STRONG></LI>
</UL>
<P>That is why<STRONG> Linux FreeS/WAN disables all transforms which use
plain DES</STRONG> for encryption.</P>
<P>DES is in the source code, because we need DES to implement our
default encryption transform,<A href="glossary.html#3DES"> Triple DES</A>
.<STRONG> We urge you not to use single DES</STRONG>. We do not provide
any easy way to enable it in FreeS/WAN, and our policy is to provide no
assistance to anyone wanting to do so.</P>
<H3><A name="40joke">40-bits is laughably weak</A></H3>
<P>The same is true, in spades, of ciphers -- DES or others -- crippled
by 40-bit keys, as many ciphers were required to be until recently
under various<A href="#exlaw"> export laws</A>. A brute force search of
such a cipher's keyspace is 2<SUP>16</SUP> times faster than a similar
search against DES. The EFF's machine can do a brute-force search of a
40-bit key space in<EM> seconds</EM>. One contest to crack a 40-bit
cipher was won by a student<A href="http://catless.ncl.ac.uk/Risks/18.80.html#subj1">
using a few hundred idle machines at his university</A>. It took only
three and half hours.</P>
<P>We do not, and will not, implement any 40-bit cipher.</P>
<H3><A name="altdes">Triple DES is almost certainly secure</A></H3>
<P><A href="glossary.html#3DES">Triple DES</A>, usually abbreviated
3DES, applies DES three times, with three different keys. DES seems to
be basically an excellent cipher design; it has withstood several
decades of intensive analysis without any disastrous flaws being found.
It's only major flaw is that the small keyspace allows brute force
attacks to succeeed. Triple DES enlarges the key space to 168 bits,
making brute-force search a ridiculous impossibility.</P>
<P>3DES is currently the only block cipher implemented in FreeS/WAN.
3DES is, unfortunately, about 1/3 the speed of DES, but modern CPUs
still do it at quite respectable speeds. Some<A href="glossary.html#benchmarks">
speed measurements</A> for our code are available.</P>
<H3><A name="aes.ipsec">AES in IPsec</A></H3>
<P>The<A href="glossary.html#AES"> AES</A> project has chosen a
replacement for DES, a new standard cipher for use in non-classified US
government work and in regulated industries such as banking. This
cipher will almost certainly become widely used for many applications,
including IPsec.</P>
<P>The winner, announced in October 2000 after several years of analysis
and discussion, was the<A href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael/">
Rijndael</A> cipher from two Belgian designers.</P>
<P>It is almost certain that FreeS/WAN will add AES support.<A href="web.html#patch">
AES patches</A> are already available.</P>
<H2><A name="press">Press coverage of Linux FreeS/WAN:</A></H2>
<H3><A NAME="26_6_1">FreeS/WAN 1.0 press</A></H3>
<UL>
<LI><A href="http://www.wired.com/news/news/technology/story/19136.html">
Wired</A> "Linux-Based Crypto Stops Snoops", James Glave April 15 1999</LI>
<LI><A href="http://slashdot.org/articles/99/04/15/1851212.shtml">
Slashdot</A></LI>
<LI><A href="http://dgl.com/itinfo/1999/it990415.html">DGL</A>, Damar
Group Limited; looking at FreeS/WAN from a perspective of business
computing</LI>
<LI><A href="http://linuxtoday.com/stories/5010.html">Linux Today</A></LI>
<LI><A href="http://www.tbtf.com/archive/1999-04-21.html#Tcep">TBTF</A>,
Tasty Bits from the Technology Front</LI>
<LI><A href="http://www.salonmagazine.com/tech/log/1999/04/16/encryption/index.html">
Salon Magazine</A> "Free Encryption Takes a Big Step"</LI>
</UL>
<H3><A name="release">Press release for version 1.0</A></H3>
<PRE> Strong Internet Privacy Software Free for Linux Users Worldwide
Toronto, ON, April 14, 1999 -
The Linux FreeS/WAN project today released free software to protect
the privacy of Internet communications using strong encryption codes.
FreeS/WAN automatically encrypts data as it crosses the Internet, to
prevent unauthorized people from receiving or modifying it. One
ordinary PC per site runs this free software under Linux to become a
secure gateway in a Virtual Private Network, without having to modify
users' operating systems or application software. The project built
and released the software outside the United States, avoiding US
government regulations which prohibit good privacy protection.
FreeS/WAN version 1.0 is available immediately for downloading at
http://www.xs4all.nl/~freeswan/.
"Today's FreeS/WAN release allows network administrators to build
excellent secure gateways out of old PCs at no cost, or using a cheap
new PC," said John Gilmore, the entrepreneur who instigated the
project in 1996. "They can build operational experience with strong
network encryption and protect their users' most important
communications worldwide."
"The software was written outside the United States, and we do not
accept contributions from US citizens or residents, so that it can be
freely published for use in every country," said Henry Spencer, who
built the release in Toronto, Canada. "Similar products based in the
US require hard-to-get government export licenses before they can be
provided to non-US users, and can never be simply published on a Web
site. Our product is freely available worldwide for immediate
downloading, at no cost."
FreeS/WAN provides privacy against both quiet eavesdropping (such as
"packet sniffing") and active attempts to compromise communications
(such as impersonating participating computers). Secure "tunnels" carry
information safely across the Internet between locations such as a
company's main office, distant sales offices, and roaming laptops. This
protects the privacy and integrity of all information sent among those
locations, including sensitive intra-company email, financial transactions
such as mergers and acquisitions, business negotiations, personal medical
records, privileged correspondence with lawyers, and information about
crimes or civil rights violations. The software will be particularly
useful to frequent wiretapping targets such as private companies competing
with government-owned companies, civil rights groups and lawyers,
opposition political parties, and dissidents.
FreeS/WAN provides privacy for Internet packets using the proposed
standard Internet Protocol Security (IPSEC) protocols. FreeS/WAN
negotiates strong keys using Diffie-Hellman key agreement with 1024-bit
keys, and encrypts each packet with 168-bit Triple-DES (3DES). A modern
$500 PC can set up a tunnel in less than a second, and can encrypt
6 megabits of packets per second, easily handling the whole available
bandwidth at the vast majority of Internet sites. In preliminary testing,
FreeS/WAN interoperated with 3DES IPSEC products from OpenBSD, PGP, SSH,
Cisco, Raptor, and Xedia. Since FreeS/WAN is distributed as source code,
its innards are open to review by outside experts and sophisticated users,
reducing the chance of undetected bugs or hidden security compromises.
The software has been in development for several years. It has been
funded by several philanthropists interested in increased privacy on
the Internet, including John Gilmore, co-founder of the Electronic
Frontier Foundation, a leading online civil rights group.
Press contacts:
Hugh Daniel, +1 408 353 8124, hugh@toad.com
Henry Spencer, +1 416 690 6561, henry@spsystems.net
* FreeS/WAN derives its name from S/WAN, which is a trademark of RSA Data
Security, Inc; used by permission.</PRE>
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