Hi Jeff,
I have just switched from crypto++ version 5.2.1 to 5.5.2 to fix
another problem I was having (my other posting).
What is the version that Marcel has uploaded? is that on the DPVal
application or on crypto++ code?
By the way, I was able to initialize the ECDH properly by parsing all
the parameters that where given to me in the Domain Parameters. Quite
a lot of work, specially some of them, like G. Reading the spec for
X9.63 helped a little...
Thank you.
Christian
On Sep 29, 7:10 pm, "Jeffrey Walton" <[EMAIL PROTECTED]> wrote:
> Hi Christian,
>
> Marcel has upload a version of ECB which does not generate negative
> parameters.
>
> Jeff
>
> On 9/27/07, Jeffrey Walton <[EMAIL PROTECTED]> wrote:
>
>
>
> > Hi Christian,
>
> > > a %= p; ----- why is this done?
> > > b %= p; ----- why is this done?
> > > x %= p;
> > > y %= p;
>
> > Certicom requirements. Domain Parameters are in the interval [0, p-1].
> > Some programs used to create curves use negative values.
>
> > Jeff
>
> > On 9/27/07, greatx <[EMAIL PROTECTED]> wrote:
>
> > > I still have my questions about the domain parameters.
>
> > > Question 1:
> > > -----------------
> > > >From the DPVal example (thanks Jeffrey) they mention the 'p', but is
> > > this the same as the prime 'p' from my ASN1 data (in the first
> > > posting)?
> > > DPVal sample code:
> > > // This is Curve P-112 from NIST
> > > CryptoPP::Integer
> > > p("6277101735386680763835789423207666416083908700390324961279");
>
> > > Given ASN1 data:
> > > ... OBJECT IDENTIFIER prime-field (1 2 840 10045 1 1)
> > > INTEGER -----> prime 'p'
> > > 00 D7 C1 34 AA 26 43 66 86 2A 18 30 25 75 D1 D7
> > > 87 B0 9F 07 57 97 DA 89 F5 7E C8 C0 FF
> > > ...
> > > ...
>
> > > Question 2:
> > > -----------------
> > > Based on the sample code from DPVal:
> > > Integer p; ------ load prime 'p' here
> > > Integer a; ------ load curve equation parameter 'a' here
> > > Integer b; ------ load curve equation parameter 'b' here
> > > Integer f; ------ load the cofactor 'f' here
> > > Integer n; ------- load the group order 'n' here
> > > a %= p; ----- why is this done?
> > > b %= p; ----- why is this done?
> > > x %= p;
> > > y %= p;
> > > ECP ec( p, a, b ); // is 'ec' the curve equation?
> > > PrivateKey.Initialize( ec, ECP::Point( x, y ), n, f );
>
> > > In my ASN1 data, 'a' and 'b' are in an OCTET STRING form. Can I pass
> > > that instead of an INTEGER? or do I have to convert from the OCTET to
> > > INTEGER before giving it to crypto++?
> > > In my ASN1 data, 'G' is the encoded Group Generator. Is this needed to
> > > be passed? What about:
> > > DL_GroupParameters_EC<ECP> gp;
> > > gp.Initialize(ec, G, n, f); ----- is G the same as ECP::Point( x,
> > > y )? if so, my G is given as an OCTET, how do I pass it in here? is
> > > the last parameter k the same as the cofactor 'f'??
>
> > > Thanks.
> > > Christian- Hide quoted text -
>
> - Show quoted text -
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