| ...challenge has been met.
Date: Tue, 28 Jan 1997 15:59:15 -0800 (PST)
From: Ian Goldberg <[email protected]>
Subject: Last nail for US crypto export policy?
EXPORTABLE CRYPTOGRAPHY TOTALLY INSECURE: CHALLENGE CIPHER BROKEN IMMEDIATELY
January 28, 1997 - Ian Goldberg, a UC Berkeley graduate student, announced
today that he had successfully cracked RSA Data Security Inc.'s 40-bit
challenge cipher in just under 3.5 hours.
RSA challenged scientists to break their encryption technology, offering a
$1000 award for breaking the weakest version of the code. Their offering
was designed to stimulate research and practical experience with the security
of today's codes.
The number of bits in a cipher is an indication of the maximum level of
security the cipher can provide. Each additional bit doubles the potential
security level of the cipher. A recent panel of experts recommended
using 90-bit ciphers, and 128-bit ciphers are commonly used throughout
the world, but US government regulations restrict exportable US products
to a mere 40 bits.
Goldberg's announcement, which came just three and a half hours after
RSA started their contest, provides very strong evidence that 40-bit
ciphers are totally unsuitable for practical security. "This is the
final proof of what we've known for years: 40-bit encryption technology
is obsolete," Goldberg said.
The US export restrictions have limited the deployment of technology
that could greatly strengthen security on the Internet, often affecting
both foreign and domestic users. "We know how to build strong
encryption; the government just won't let us deploy it. We need strong
encryption to uphold privacy, maintain security, and support commerce on
the Internet -- these export restrictions on cryptography must be
lifted," Goldberg explained. Fittingly, when Goldberg finally
unscrambled the challenge message, it read: "This is why you should use
a longer key."
Goldberg used UC Berkeley's Network of Workstations (known as the NOW) to
harness the computational resources of about 250 idle machines. This allowed
him to test 100 billion possible "keys" per hour -- analogous to safecracking
by trying every possible combination at high speed. This amount of computing
power is available with little overhead cost to students and employees at
many large educational institutions and corporations.
Goldberg is a founding member of the ISAAC computer security research group
at UC Berkeley. In the Fall of 1995, the ISAAC group made headlines by
revealing a major security flaw in Netscape's web browser.
|
| The 40 bit challenge was one of thirteen contests.
There are remaining 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128 RSA
cyphers and DES (which uses a 56 bit key) remaining. The 40 bit contest
had a $1000 prize. The others have a $10000 prize.
DES should be interesting since its 56 bit key has peculiar properties
that effectivly knock two or three bits off.
R.
|
| re: .2
The 48-bit key fell about a month ago (February 10), after thirteen
days of searching using about 5,000 nodes. The rest are still up
for grabs.
re: .3
Certainly, "DIGITAL" won't be working to solve this. And unfortunately,
it seems folks don't have much time to work on "unfunded projects" like
this unofficially, no matter how many Alphas we may have idle on the
E-net.
|