The RC5 56bit challenge - help break 56bit RC5 encryption key

The RC5 56bit challenge - help break 56bit RC5 encryption key

Post by Alan C » Wed, 05 Mar 1997 04:00:00


Some of you may now know about the attempt to break 56bit RC5 as part
of the RSA challenge. 40 and 48 bits have been done. 56bit is a colossal
challenge but has been started. Whichever group cracks the key gets $1000.

We are trying to get as many Linux folks as possible involved in the
challenge and hopefully as one giant group using the id

and the sheer number of Linux users to stick ourselves on the top
of the stats page. In the unlikely even we do crack the key the money
will go to the Linux Development Grant Fund (Linux International).

To join in ftp the clients from and run
them with

or for some clients

(you may want to nice this)

SMP folks should run one client per CPU.

Non US sites please be aware of the potential crypto export rules...

You might want to run it via "nice". It will then just soak idle CPU.

For more info see - info and stats - we want to be top! - RSA - the RC5 creators and challenge setters

Some folks may have seen an older version of this message, I didnt send
it because the clients where binary only and I could not verify they
were correct. The message included below is PGP signed by Roman and
gives the MD5 sums. New clients may appear from time to time. If so
there will be a new md5 sum file also signed by Roman with them.

Alan Cox


> Here are the md5sums of the currently available binaries/source for
> the rc5 56bit client located on  
> If you have any questions regarding the signatures/validity of the binaries
> please contact me:

> 695fef5f46456b5baca81c5cd7457428  rc5-client-2.01.tar.gz
> 9b29ae161b003a1872b0db0a5991a97d  rc5-client-aix4-ppc
> 2bfc844a0002eab5577d8426074d9377  rc5-client-aix4-ppc-socks4
> 5139ad096ca0940cb36d2176ff7e2a22  rc5-client-aix4-ppc-socks5
> b5f304e084bd170d93e4b25a63907a7f  rc5-client-bsdi
> 3b75fc52e295b2365b44bedf07cd2db1  rc5-client-hpux9
> 6238b429d2033c40bcb98f89e57139e7  rc5-client-hpux9-socks4
> 57cba203274c6ef029d07f086645cb85  rc5-client-irix-mips1-32
> b2d3988f00021ec02cbc14d85b85ac89  rc5-client-irix-mips2-32
> 312cfa1e79b2dcba64e5e51629089882  rc5-client-irix-mips3-64
> f1cc1f22a63ceede0d038fdda5d45bfa  rc5-client-irix-mips3-n32
> a8e685864e863f1139c9e8ad4cd74fca  rc5-client-irix-mips4-64
> 11e4c2184c12d67845832609ddee26a5  rc5-client-irix-mips4-n32
> ed1baa8ed9efdad2d1c3ee7cf89869a3  rc5-client-linux-i586
> be44795e34e5a3dc3141f2cf30e8a746  rc5-client-linux-sparc
> 3154269bdca54ceede1c547ed70bf1a4  rc5-client-os2-i386.exe
> 4ed7432d8e14842e0480ad33c20cebd4  rc5-client-os2-i486.exe
> 07061f7f123d79af965bf5e49e94b241  rc5-client-os2-i586.exe
> 75964bb5448e4105115b0e995c18bca1  rc5-client-solaris-supersparc
> 2dde652b39870efddb88ef32f0b82142  rc5-client-solaris-supersparc-socks5
> 023b95ca459480c241b653a0daa84cb5  rc5-client-solaris-ultrasparc
> 8638161336201b243d7463feb242bd11  rc5-client-solaris-ultrasparc-socks5
> 586db9b60f4e60e7da50e1642afda784  rc5-client-sunos-socks4

> Version: 2.6.3i
> Charset: noconv

> iQCVAwUBMxIaZVT4NsS8aMSdAQE5kwQAkejmP7oVJmBBfwbGKu7c7LriWvqAw9sz
> KHVr+++UU2fVDrm1//Mcn2hgbFJzuWgdXL4DBitBVxz4bbg+jCF9THq44LuK1dLX
> e7k+D2nqLOK1LR+WyGGfDorgo6Pw4xFI3m4QBf0VLfWpPGRZjHFxY/jwSt6rxQ32
> ICckUpPWIEw=
> =zeC4

- --
This article has been digitally signed by the moderator, using PGP. has PGP key for validating signature.

PLEASE remember a short description of the software and the LOCATION.
This group is archived at

Version: 2.6.3i
Charset: noconv



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