169 lines
7.9 KiB
Plaintext
169 lines
7.9 KiB
Plaintext
|
|
Archive-name: cryptography-faq/part09
|
|
|
|
|
|
This is the ninth of ten parts of the sci.crypt FAQ. The parts are
|
|
mostly independent, but you should read the first part before the rest.
|
|
We don't have the time to send out missing parts by mail, so don't ask.
|
|
Notes such as ``[KAH67]'' refer to the reference list in the last part.
|
|
|
|
|
|
|
|
Contents:
|
|
|
|
9.1. What is the National Security Agency (NSA)?
|
|
9.2. What are the US export regulations?
|
|
9.3. What is TEMPEST?
|
|
9.4. What are the Beale Ciphers, and are they a hoax?
|
|
9.5. What is the American Cryptogram Association, and how do I get in touch?
|
|
9.6. Is RSA patented?
|
|
9.7. What about the Voynich manuscript?
|
|
|
|
|
|
9.1. What is the National Security Agency (NSA)?
|
|
|
|
The NSA is the official security body of the U.S. government. It
|
|
was given its charter by President Truman in the late 40's, and
|
|
has continued research in cryptology till the present. The NSA is
|
|
known to be the largest employer of mathematicians in the world,
|
|
and is also the largest purchaser of computer hardware in the
|
|
world. Governments in general have always been prime employers of
|
|
cryptologists. The NSA probably possesses cryptographic expertise many
|
|
years ahead of the public state of the art, and can undoubtedly break
|
|
many of the systems used in practice; but for reasons of national
|
|
security almost all information about the NSA is classified.
|
|
|
|
Bamford's book [BAMFD] gives a history of the people and operations of
|
|
the NSA. The following quote from Massey [MAS88] highlights the
|
|
difference between public and private research in cryptography:
|
|
|
|
``... if one regards cryptology as the prerogative of government,
|
|
one accepts that most cryptologic research will be conducted
|
|
behind closed doors. Without doubt, the number of workers engaged
|
|
today in such secret research in cryptology far exceeds that of
|
|
those engaged in open research in cryptology. For only about 10
|
|
years has there in fact been widespread open research in
|
|
cryptology. There have been, and will continue to be, conflicts
|
|
between these two research communities. Open research is common
|
|
quest for knowledge that depends for its vitality on the open
|
|
exchange of ideas via conference presentations and publications in
|
|
scholarly journals. But can a government agency, charged with
|
|
responsibilities of breaking the ciphers of other nations,
|
|
countenance the publication of a cipher that it cannot break? Can
|
|
a researcher in good conscience publish such a cipher that might
|
|
undermine the effectiveness of his own government's code-breakers?
|
|
One might argue that publication of a provably-secure cipher would
|
|
force all governments to behave like Stimson's `gentlemen', but one
|
|
must be aware that open research in cryptography is fraught with
|
|
political and ethical considerations of a severity than in most
|
|
scientific fields. The wonder is not that some conflicts have
|
|
occurred between government agencies and open researchers in
|
|
cryptology, but rather that these conflicts (at least those of which
|
|
we are aware) have been so few and so mild.''
|
|
|
|
9.2. What are the US export regulations?
|
|
|
|
In a nutshell, there are two government agencies which control
|
|
export of encryption software. One is the Bureau of Export
|
|
Administration (BXA) in the Department of Commerce, authorized by
|
|
the Export Administration Regulations (EAR). Another is the Office
|
|
of Defense Trade Controls (DTC) in the State Department, authorized
|
|
by the International Traffic in Arms Regulations (ITAR). As a rule
|
|
of thumb, BXA (which works with COCOM) has less stringent
|
|
requirements, but DTC (which takes orders from NSA) wants to see
|
|
everything first and can refuse to transfer jurisdiction to BXA.
|
|
|
|
The newsgroup misc.legal.computing carries many interesting
|
|
discussions on the laws surrounding cryptographic export, what
|
|
people think about those laws, and many other complex issues which
|
|
go beyond the scope of technical groups like sci.crypt. Make sure to
|
|
consult your lawyer before doing anything which will get you thrown in
|
|
jail; if you are lucky, your lawyer might know a lawyer who has at
|
|
least heard of the ITAR.
|
|
|
|
9.3. What is TEMPEST?
|
|
|
|
TEMPEST is a standard for electromagnetic shielding for computer
|
|
equipment. It was created in response to the discovery that
|
|
information can be read from computer radiation (e.g., from a CRT) at
|
|
quite a distance and with little effort.
|
|
|
|
Needless to say, encryption doesn't do much good if the cleartext
|
|
is available this way.
|
|
|
|
9.4. What are the Beale Ciphers, and are they a hoax?
|
|
|
|
(Thanks to Jim Gillogly for this information and John King for
|
|
corrections.)
|
|
|
|
The story in a pamphlet by J. B. Ward (1885) goes: Thomas
|
|
Jefferson Beale and a party of adventurers accumulated a huge mass
|
|
of treasure and buried it in Bedford County, Virginia, leaving
|
|
three ciphers with an innkeeper; the ciphers describe the
|
|
location, contents, and intended beneficiaries of the treasure.
|
|
Ward gives a decryption of the second cipher (contents) called B2;
|
|
it was encrypted as a book cipher using the initial letters of the
|
|
Declaration of Independence (DOI) as key. B1 and B3 are unsolved;
|
|
many documents have been tried as the key to B1.
|
|
|
|
Aficionados can join a group that attempts to solve B1 by various
|
|
means with an eye toward splitting the treasure:
|
|
|
|
The Beale Cypher Association
|
|
P.O. Box 975
|
|
Beaver Falls, PA 15010
|
|
|
|
You can get the ciphers from the rec.puzzles FAQL by including the
|
|
line:
|
|
|
|
send index
|
|
|
|
in a message to netlib@peregrine.com and following the directions.
|
|
(There are apparently several different versions of the cipher
|
|
floating around. The correct version is based on the 1885 pamphlet,
|
|
says John King <kingj@hpcc01.corp.hp.com>.)
|
|
|
|
Some believe the story is a hoax. Kruh [KRU88] gives a long list of
|
|
problems with the story. Gillogly [GIL80] decrypted B1 with the DOI
|
|
and found some unexpected strings, including ABFDEFGHIIJKLMMNOHPP.
|
|
Hammer (president of the Beale Cypher Association) agrees that this
|
|
string couldn't appear by chance, but feels there must be an
|
|
explanation; Gwyn (sci.crypt expert) is unimpressed with this
|
|
string.
|
|
|
|
9.5. What is the American Cryptogram Association, and how do I get in touch?
|
|
|
|
The ACA is an organization devoted to cryptography, with an emphasis
|
|
on cryptanalysis of systems that can be attacked either with
|
|
pencil-and-paper or computers. Its organ ``The Cryptogram'' includes
|
|
articles and challenge ciphers. Among the more than 50 cipher types in
|
|
English and other languages are simple substitution, Playfair,
|
|
Vigenere, bifid, Bazeries, grille, homophonic, and cryptarithm.
|
|
|
|
Dues are $15 for one year (6 issues); more outside of North America;
|
|
less for students under 18 and seniors. Subscriptions should be sent
|
|
to ACA Treasurer, 18789 West Hickory St., Mundelein, IL 60060.
|
|
|
|
9.6. Is RSA patented?
|
|
|
|
Yes. The patent number is 4,405,829, filed 12/14/77, granted 9/20/83.
|
|
For further discussion of this patent, whether it should have been
|
|
granted, algorithm patents in general, and related legal and moral
|
|
issues, see comp.patents and misc.legal.computing. For information
|
|
about the League for Programming Freedom see [FTPPF]. Note that one of
|
|
the original purposes of comp.patents was to collect questions such as
|
|
``should RSA be patented?'', which often flooded sci.crypt and other
|
|
technical newsgroups, into a more appropriate forum.
|
|
|
|
9.7. What about the Voynich manuscript?
|
|
|
|
nelson@reed.edu (Nelson Minar) says there is a mailing list on the
|
|
subject. The address to write to subscribe to the VMS mailing list
|
|
is: <voynich-request@rand.org>
|
|
|
|
the ftp archive is: rand.org:/pub/voynich
|
|
|
|
There's all sorts of information about the manuscript itself, of
|
|
course. A good bibliography can be found on the ftp site. [KAH67]
|
|
gives a good introduction.
|