Talk:The Thirteenth Labour: Difference between revisions

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(It still seems to me you're attacking the wrong cipher.)
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[[User:Chimera245|Chimera245]] Edited to clarify twice, last at 17:00, 6 June 2006 (PDT)
[[User:Chimera245|Chimera245]] Edited to clarify twice, last at 17:00, 6 June 2006 (PDT)
:I am familiar with this notation (I'm a cryptographer) but it's not standard for block ciphers in general - it's specific to RC5.  RC5-32/12/8 processes 64 bits at a time.  RC5-64/12/8 would process 128 bits at a time.  The number is half what you would expect because RC5 splits the input into two halves and each half acts on the other.  I have checked the original RC5 paper - I recommend you do the same if you think I'm mistaken.  Thanks! [[User:Ciphergoth|Ciphergoth]] 02:37, 22 June 2006 (PDT)

Revision as of 09:37, 22 June 2006

As far as I can tell "Assault on 13th Labour" are attacking the wrong cipher. They are attacking standard RC5 - that is, RC5-32/12/8 - when they should be attacking the nonstandard variant RC5-64/12/8. Ciphergoth 09:00, 3 June 2006 (PDT)

Comment from chimera245: The Assault Client was developped from the RCCRYPT package - according to Von's hint - version 1.6 to be exact (though 1.4 id identical in decryption terms). From the first page of the Unfiction thread:

64/12/8

This is VERY standard notation for the encryption used. It means that when it's being processed, 64 bits of the text are processed at a time. They are processed 12 times and that the key used to process them is 8 bytes (64 bits) long. This makes it almost certain that it's RC5-64 encryption.

Each block is processed in two 64 bit words at a time, for 12 rounds, using an 8 byte key.

The source has been verified by people who were actually involved in the original d.net assault on RC5-64 as a valid port of RCCRYPT 1.4 or 1.6. All of the clients used in this attempt (even those prior to mine) have been based upon the same premise - that Von's hint of RCCRYPT is the appropriate pointer. In actual fact, RCCRYPT calls itself 128 bit, not 64 bit - but by definition it is RC5-64.

Chimera245 Edited to clarify twice, last at 17:00, 6 June 2006 (PDT)

I am familiar with this notation (I'm a cryptographer) but it's not standard for block ciphers in general - it's specific to RC5. RC5-32/12/8 processes 64 bits at a time. RC5-64/12/8 would process 128 bits at a time. The number is half what you would expect because RC5 splits the input into two halves and each half acts on the other. I have checked the original RC5 paper - I recommend you do the same if you think I'm mistaken. Thanks! Ciphergoth 02:37, 22 June 2006 (PDT)