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RSA-640 Factored

Posted by ScuttleMonkey on from the bigger-better-deal dept.

gslin writes to tell us MathWorld News is reporting that RSA-640 has been factored. F. Bahr, M. Boehm, J. Franke, and T. Kleinjung, memebers of the German Federal Agency for Information Technology Security (BSI) announced they had cracked the 193-digit number last Friday using the General Number Field Sieve. The team purportedly used 80 opteron CPUs and 5 months to achieve victory.

13 of 299 comments (clear)

  1. easy by Anonymous Coward · · Score: 5, Funny

    640=2*2*2*2*2*2*2*5.

    What do I win?

  2. Time to turn off the Internet... by adlib24 · · Score: 4, Funny

    I wish had nothing better to do for five moths than factor numbers...geez...who needs the Internet when there are numbers to factor. :)

  3. Hmmm. by jd · · Score: 4, Funny

    The German Federal Government is short on cash, I know, but resorting to funding the "Agency for Information Technology Security" by winning RSA contests? Besides, if they're so up on IT security, why didn't they just cheat by logging onto RSA's computers?

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  4. Arrgh! by Ventriloquate · · Score: 5, Funny

    My TI-82 was just about to solve that one!

  5. I got part of it by pHatidic · · Score: 4, Funny

    I knew that one of the factors ended in a 1 and the other ended in a 9 or that they both ended in 3. Am I eligible to split the prize?

    1. Re:I got part of it by stevey · · Score: 4, Funny
      Turns out these number anomalies only happen with base-10 numbers. When you have base-16 numbers, these mysterious relationships of the last digits disappear.

      If only there were some magical way of turning numbers from base-16 into base-10. Then those tricks would suddenly be useful again...

  6. "640 bits... by Joe+Random · · Score: 4, Funny

    should be enough for anyone."

  7. Zombie Cluster by happyEverGeek · · Score: 5, Funny

    I wonder how long it would have taken 1.5 million zombie PCs.

    --
    To a politician, one email equals one voter.
  8. An idea by bradbeattie · · Score: 5, Funny

    Why don't we just start using 1.44mb encryption keys. We'd finally have a use for all of these floppies.

  9. Re:I'll wait for RSA-2048 by adlib24 · · Score: 5, Funny
    Of course we would only do perfectly harmless things... like...um...use Xbox Live to construct a cluster to factor RSA-4096. ;)

    p.s. all your xbox is belong to us.

  10. RSA Cracked by Joseph_V · · Score: 4, Funny

    And in only 5 months... how P Q ular.

  11. Re:Factor? by obender · · Score: 5, Funny
    but an algorithm may exist that can factor primes in polynomial time

    Bill Gates wrote something similar in The Road Ahead:

    The obvious mathematical breakthrough would be development of an easy way to factor large prime numbers.

    Sorry to break it to you boys but I know an algorithm that can do that in constant time: the factors of any prime number are 1 and the number itself.

  12. It works in all bases. by lheal · · Score: 5, Funny

    For any base b, the sum of the digits (in base b) of a multiple of (b-1) add to a multiple of (b-1). The proof is fairly simple: http://www.pseudorandom.co.uk/2002/maths/divby9/.

    For instance, in base 16, 3 * F (45 dec) is 2D, and 2+D=F.

    This leads to a (slow) algorithm for primality check. For a given number r, simply (hah!) check all the bases up to about log_b(r) to see if all your base r belong to us.

    --
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