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Date: Tue, 18 Sep 2012 04:15:39 -0700 (PDT)
From: deepika dutta <deepikadutta_19@...oo.com>
To: "john-dev@...ts.openwall.com" <john-dev@...ts.openwall.com>
Subject: Bitsliced DES - SSE

Hi, I am looking into the SSE part of bitsliced des and working on adding the plain des encryption part in it. I am working with x86-sse.S. I got an idea of what is happening there but I have following doubt, please answer it so that i can proceed further... I would like to do this part as it will aid in my understanding also.

I had added a code in MSCHAP to fill plaintext in bitsliced form which was copied to DES_bs_all.B before starting encryption. (This code i have shifted now to DES-bs_b.c to make it available to any algorithm.) When using sse (linux-x86 build for 32/64 bit), the DES_bs_vector becomes a 2D array with 64 rows and 4 columns. Without sse the array was  1D each bit was put as 0 or -1 in array elements. Now for SSE, whether I should bitslice the plaintext in C function populating each column with same value or do it in assembly using 128 bit sse instructions? I know it would be easier to do in C but will it have any performance issues?? 


 
Cheers,
Deepika
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