RC5-72 (distributed.net) Key Challenge

Discussion in 'Distributed Computing' started by WardC, Aug 4, 2010.

  1. macrumors 68030

    WardC

    Joined:
    Oct 17, 2007
    Location:
    Fort Worth, TX
    #1
    Anybody cracking RC5 on their Mac? The new Mac OS X client for nVidia CUDA-enabled cards is supposed to be really good...people are getting as much as 50x faster speeds when using the CUDA-enabled GPU to crack keys.

    I participated in the RC5-64 challenge, and I've been doing a bit of cracking on the RC5-72 challenge now. RSA is not sponsoring the contest anymore, but distributed.net is still giving $1000 to the winner.

    http://www.distributed.net
     
  2. macrumors P6

    twoodcc

    Joined:
    Feb 3, 2005
    Location:
    Right side of wrong
    #2
    I'm not sure what RC5 is
     
  3. macrumors 6502

    Joined:
    Jul 31, 2008
    #3
    Did that around the time SETI was introduced... Not much point to it though unlike current medical projects...
     
  4. thread starter macrumors 68030

    WardC

    Joined:
    Oct 17, 2007
    Location:
    Fort Worth, TX
    #4
    It's a security-based encryption key challenge, to test the security of 72-bit RC5 keys, to see if it can be cracked. 64-bit RC5 encryption was cracked successfully in 2002. It took them about 5 years to crack that code. They are less than 1% done cracking the 72-bit key, and they have been at it since the RC5-64 challenge ended in 2002 (8 years). About 0.9% through testing all possible keys in the keyspace to see if they match.

    It's a distributed computing effort, and you run a client program on your machine, which fetches keys to test, then the cruncher tests each block of keys, and sends the data back to the server. Your stats are logged daily on a stats server, and it's a competitve contest to see who can crack the most keys. Faster machines will crack better, and the more computers you have running the client, the better.

    RSA securities (the company that did security for Netscape) was originally hosting the contest with a $10,000 prize to the winner. The prize was to be split between distributed.net, the winner, the winner's team, and a voted charity organization. The winner got $1,000 and his team got $1,000 to split between themselves.

    So, in sum, RC5-72 is a key-cracking challenge to test the strength and security of 72-bit key encryption. We all use 128-bit keys now for internet security, which are practically as safe as we can get. At the rate they are cracking RC5-72, it could take as much as 25 more years to finally crack it and find the matching key!!
     
  5. macrumors P6

    twoodcc

    Joined:
    Feb 3, 2005
    Location:
    Right side of wrong
    #5
    oh ok. thanks for the explanation. i guess it doesn't seem totally useless, but not as useful as medical projects
     

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