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Date: Tue, 20 Dec 2011 17:56:15 +0530
From: piyush mittal <piyush.cse29@...il.com>
To: john-dev@...ts.openwall.com
Subject: Re: Bit slice implementation of DES based hashes

>
> Can you please describe what bitslicing is, in your own words?
>

In Bitslicing ,all combination of bits operates simultaneously and
parallelly  i.e  each bit will behave as a different processor.The same
concept we are using here in DES.Like in 64 bit machine 64 plain text's
encryption can be done simultaneously and parrallely.However here we have
used non standard implementation of DES i.e structure of DES is broken down
into AND,OR NOR.. gates to further increase the speed.

What portion(s) of the DES block(s) does each element of B[] hold?
>
> What portion(s) of the DES key(s) does each element of K[] hold?
>
>
64 elements of  block is holded by each element of B[]
56 elements of block is holded by each element of K[]


It does not have any mode.  It is a single DES encryption.
>

I can't predict directly from the code but I have read from its algo.

Now I am starting NETLM_fmt.c and Oracle code I will also give you after it.
Now I will not inquire further questions to you.


Thanks a lot.






On Tue, Dec 20, 2011 at 4:09 PM, Solar Designer <solar@...nwall.com> wrote:

> On Tue, Dec 20, 2011 at 08:16:53AM +0530, piyush mittal wrote:
> > Implementation is completed and I have used Unicodes as well and that is
> > working fine but I am getting self test failed this is because the
> > implementation is not fully correct.
>
> Well, then you don't know if it's in fact completed or not.  It might as
> well be totally wrong, needing a complete rewrite before it can work.
>
> Please try to get it working for at least one test vector.
>
> > The crypt function of LM on which this
> > implem. is based upon have ECB mode.
>
> It does not have any mode.  It is a single DES encryption.
>
> > but in oracle we need CBC,
>
> Like I said before, you may implement CBC mode externally to that function.
>
> > char *plain_salt_mix=utf16_to_utf8(cur_salt); //cur_salt is a combination
> > of (username+password) in UTF 16
> > length=strlen(plain_salt_mix);
> >
> > *
> > *for(i=0;i<length;i++)
> > DES_bs_all.B[i][0]=plain_salt_mix[i];
> >
> > for(j=i;i<64-length;i++)
> > DES_bs_all.B[i][0]=0;
> >
> > Is this correct?
>
> I don't understand what you're trying to achieve with this, but it can't
> possibly be correct.
>
> Let's get back to the basics:
>
> Can you please describe what bitslicing is, in your own words?
>
> What portion(s) of the DES block(s) does each element of B[] hold?
>
> What portion(s) of the DES key(s) does each element of K[] hold?
>
> Thanks,
>
> Alexander
>



-- 
Piyush Mittal
Department of Computer Science and Engineering
National Institute of Technology,Rourkela
INDIA

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