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56bit DES crack: Bruce Schneier analysiert

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Rigo

>Date: Mon, 17 Aug 1998 18:41:59 +0200
>From: q/depesche <depesche@quintessenz.at>
>X-Mailer: Mozilla 4.05 [de] (WinNT; I)
>To: list <quintessenz-list@quintessenz.at>
>Subject: 56bit DES crack: Bruce Schneier analysiert
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>
>q/depesche 98.8.17/1
>updating   98.7.21/2
>
>56bit DES crack: Bruce Schneier analysiert
>
>Zum DES/Schlüssel/brechers der Electronic Frontier
>Foundation fällt dem Ober/Cypherpunk gleich mehrfach
>Despektierliches ein: 
>
>Der EFF DEScracker benützt
>- alte, fade Chiptechnologie
>- Simples Hardwaredesign
>- keine besondere Software
>- kein Cryptographie/Programm
>- ist also kein Meisterwerk der technik sondern ein ziemlich
>dummes Geradeaus/Brute/force/Gerät
>
>ABER
>- der DESCracker ist hübsch skalierbar
>- wobei jede weitere Maschine nur noch ein Viertel der
>ersten kosten wird.
>
>Fazit: Wenn eine Bürgerrechtsorganisation mit veralteter
>Technologie ein in jeder Hinsicht verbesserungswürdiges
>Gerät bauen kann, das immerhin den 56bit DES
>Standard/Schlüssel crackt - dann kann die vom FBI hartnäckig
>geäusserte Behauptung, die Behörden hätten Schwierigkeiten,
>56bit Schlüssel zu entziffern, nur Zeichen von Inkompetenz
>und/oder einer Lüge sein.   
>
>ceterum/censeo nicht vergessen: Dass 56bit DES der
>Online-Banking Standard in Östreeich und Deutschland ist.
>
>
>-.-.- --.-  -.-.- --.-  -.-.- --.-
>A Hardware DES Cracker
>
>by Bruce Schneier 
>
>August 15, 1998 On 17 July the Electronic Frontier
>Foundation (EFF) announced the construction of a DES
>brute-force hardware cracker.  This $220,000 device can
>break a DES key in an average of 4.5 days.
>
>The news here is not that DES is insecure, that hardware
>algorithm-crackers can be built, or that a 56-bit key length
>is too short.  We've known all of this already;
>cryptographers have been saying it for years.  (My book said
>it in 1994.) Technological predictions made about the
>declining costs of such a machine, made in the late 1970s,
>the 1980s, and the early 1990s, turned out to be dead-on.
>
>The news is how long the government has been denying that
>these machines were possible.  As recently as 8 June 98,
>Robert Litt, principal associate deputy attorney general at
>the Department of Justice, denied that it was possible for
>the FBI to crack DES.  "[It is a myth that] we have
>supercomputers that can crack anything that is out there,"
>Litt said. "Let me put the technical problem in context: It
>took 14,000 Pentium computers working for four months to
>decrypt a single message.... We are not just talking FBI and
>NSA [needing massive computing power], we are talking about
>every police department." (See the full story at
>http://www.wired.com/news/news/politics/story/12830.html.) 
>
>My comment was that the FBI is either incompetent or lying,
>or both.
>
>EFF's machine is not cutting-edge engineering.  It is not
>state-of-the-art cryptography. It is not bleeding-edge
>technology.  The machine uses old, boring chip technologies,
>simple hardware design, not-very-interesting software, and
>no cryptography.  This is not a marvel of engineering; the
>only interesting thing is how straightforward the design
>really is.
>
>Moreover, the machine scales nicely.  EFF spent $220,000 on
>their first machine.  Now that the design work is done, they
>can build a second for about $50,000.  For every doubling of
>that price, they can double the speed of the machine (so a
>second machine for $250,000 can break DES in less than a
>day).  And Moore's Law predicts that the same machine will
>be either twice as fast or twice as cheap in another 18
>months.
>
>The EFF machine broke DES, but it could just as easily have
>been designed to break any other encryption algorithm.  The
>attack was against the key length, not against the algorithm
>design.  Moreover, a slightly more expensive design would
>have used FPGAs, allowing the system to work against a
>variety of algorithms and algorithm variants.
>
>The only solution here is to pick an algorithm with a longer
>key.  DES has a fixed 56-bit key.  Triple-DES has a 112-bit
>key; there isn't enough silicon in the galaxy or enough time
>before the sun burns out to brute-force triple-DES.  AES
>requires 128-, 192-, and 256-bit keys.
>
>The EFF is a civil liberties group, and this was just a
>demonstration project.  Government agencies like the FBI and
>the NSA would presumably spend a lot more time engineering a
>more efficient solution.  It is reasonable to assume that
>any country with an intelligence budget has built this sort
>of machine, probably one a couple of orders of magnitude
>faster.
>
>There are undoubtably many, many technical improvements that
>can be made to the EFF design to make brute-force search
>cheaper and faster.  But the fact that a civil liberties
>group can use old technology to build something that the
>adminstration has denied can be built...that's the real
>news.
>
>
>relayed by Bruce Schneier
>http://www.counterpane.com/
>
>related links
>EFF's press release: http://www.eff.org/descracker/
>
>Wired News:
>http://www.wired.com/news/news/technology/story/13800.html
>
>Cnet:
>http://www.news.com/News/Item/0%2C4%2C24322%2C00.html?sas.mail
>
>New York Times story:
>http://www.nytimes.com/library/tech/yr/mo/biztech/articles/17encrypt.html.
>
>
>-.-.- --.-  -.-.- --.-  -.-.- --.-
>TIP
>Download free PGP 5.5.3i (Win95/NT & Mac)
>http://keyserver.ad.or.at/pgp/download/
>
>-.-.- --.-  -.-.- --.-  -.-.- --.-
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