Re: [Cfrg] I-D Action:draft-kiyomoto-kcipher2-02.txt

Scott,

Oops, I was wrong about the location of the right parenthesis in
my previous message. It is (as described in the draft)

SubK2((IK[3] <<32 8) XOR (IK[3] >>32 24)) XOR (0x01, 0x00, 0x00, 0x00);

and that means (as it is written in the above)

   (1) IK[3] gets left-shifted by 8 bits
   (2) IK[3] gets right-shifted by 24 bits
   (3) call SubK2() by giving "(1) XOR (2)" as its input
       and the result will be XOR-ed with 0x01000000

not
>>   (1) IK[3] gets left-shifted by 8 bits
>>   (2) IK[3] gets right-shifted by 24 bits
>>   (3) call SubK2() by giving "(1) XOR (2) XOR 0x01000000"
>>       as the input parameter

Sorry for the confusions.

Wook

On Wed, 13 Apr 2011 23:30:35 +0900, Scott Fluhrer (sfluhrer)  
<sfluhrer@cisco.com> wrote:

>
>
>> -----Original Message-----
>> From: cfrg-bounces@irtf.org [mailto:cfrg-bounces@irtf.org] On Behalf
> Of
>> Wook Shin
>> Sent: Wednesday, April 13, 2011 4:31 AM
>> To: cfrg@irtf.org; Jim Schaad
>> Subject: Re: [Cfrg] I-D Action:draft-kiyomoto-kcipher2-02.txt
>>
>> Jim,
>>
>> That's my mistake. I think I made that mistake while converting
>> circular shift operations to the combination of XOR and
>> non-circular shit operations.
>>
>> The notation in Section 2.1 should be corrected to
>>
>>    <<n t     t-bit left shift in an n-bit register
>>    >>n t     t-bit right shift in an n-bit register
>>
>> and then, the code
>>
>>    SubK2((IK[3] <<32 8) XOR (IK[3] >>32 24))
>>      XOR (0x01, 0x00, 0x00, 0x00);
>>
>> should mean that
>>
>>   (1) IK[3] gets left-shifted by 8 bits
>>   (2) IK[3] gets right-shifted by 24 bits
>>   (3) call SubK2() by giving "(1) XOR (2) XOR 0x01000000"
>>       as the input parameter
>
> If that's what you meant, well, that's a really odd notation.
> Typically, where someone writes:
>     Func(A) op B
> They usually mean:
>    - Give the value A to function Func, then take the result, and use it
> to perform the operation with B.
>
> A more conventional way of writing what you said you meant would be:
>
>     SubK2((IK[3] <<32 8) XOR (IK[3] >>32 24) XOR
>                             (0x01, 0x00, 0x00, 0x00));
>
> So, did you mean what you wrote, or did you mean what you said you
> meant?
>
>>
>> Best regards,
>>
>> Wook
>>
>>
>>
>>
>> On Wed, 13 Apr 2011 17:23:10 +0900, Jim Schaad
> <ietf@augustcellars.com>
>> wrote:
>>
>> > You have a notation that is leaving me puzzled.
>> >
>> > In section 2.1 you say
>> >
>> >      <<n   Left circular rotation by n bits
>> >
>> >       >>n   Right circular rotation by n bits
>> >
>> > Which makes sense.
>> >
>> > However in section 2.3.2 you use the notation
>> >
>> >            SubK2((IK[3] <<32 8) XOR (IK[3] >>32 24)) XOR
>> >             (0x01, 0x00, 0x00, 0x00);
>> >
>> > Which is not covered by the above.
>> >
>> > Additionally I wonder if you mean to use IK[3] in both locations
> here
>> as
>> > (I think)
>> >
>> > (IK[3] << 8) XOR (IK[3] >> 24) ---> (IK[3] << 8) XOR (IK[3] << (32-
>> 24))
>> > --> (IK[3] << 8) XOR (IK[3] << 8)
>> >
>> > jim
>> >
>> >> -----Original Message-----
>> >> From: Wook Shin [mailto:wookshin@kddilabs.jp]
>> >> Sent: Tuesday, April 12, 2011 6:39 PM
>> >> To: cfrg@irtf.org
>> >> Subject: Re: I-D Action:draft-kiyomoto-kcipher2-02.txt
>> >>
>> >> Hello all,
>> >>
>> >> I've revised our previous draft that explains the KCipher-2 stream
>> >> cipher.
>> >> The current version includes some code snippets written in the C
>> >> language
>> >> syntax, so that it could help implementers get clearer idea of how
>> it
>> >> works
>> >> and help them check their outputs with the test vectors mentioned
> in
>> the
>> >> draft.
>> >> The new version of the draft can be found at
>> >>    http://www.ietf.org/internet-drafts/draft-kiyomoto-kcipher2-
>> 02.txt
>> >>
>> >> I have attached a naive implementation of KCipher-2 written in C.
>> >> Two files, KCipher2.c and KCipher2.h, are in the attached .zip
> file,
>> >> and no
>> >> special option is required to compile and run the program.
>> >> The code snippets and the test vector running examples in the draft
>> are
>> >> from the the attached code.
>> >>
>> >> Please look at the new version of the draft and the code, and let
> me
>> >> have
>> >> your comments.
>> >>
>> >> Thank you,
>> >>
>> >> Wook
>>
>>
>> --
>> Wook Shin
>> Information Security Laboratory,
>> KDDI R&D Laboratories, Inc.
>> _______________________________________________
>> Cfrg mailing list
>> Cfrg@irtf.org
>> http://www.irtf.org/mailman/listinfo/cfrg

-- 
Wook Shin
Information Security Laboratory,
KDDI R&D Laboratories, Inc.