Re: ACTION-219: ECPointType

On 23 Feb 2009, at 11:15, Magnus Nyström wrote:

> I think Thomas suggestion to have a renewed look at the design is a  
> good one, but I think it would be a little strange to have the seed  
> as a child of a hash element, since the seed is not really part of  
> the hash.

> IF we are to change Brian's latest draft (but note that I'd be OK  
> with it as is), then an alternative suggestion could be something  
> like:

Looks better to me than the previous one.  I'd be happy to merge this  
into the FPWD if there are no objections.

Any comments?

> <complexType name="ECParametersType">
>      <sequence>
>        <element name="FieldID" type="dsig11:FieldIDType"/>
>        <element name="Curve" type="dsig11:CurveType"/>
>        <element name="Base" type="dsig11:ECPointType"/>
>        <element name="Order" type="ds:CryptoBinary"/>
>        <element name="CoFactor" type="integer" minOccurs="0"/>
>        <element name="ECValidationData"
>                 type="dsig11:ECValidationDataType" minOccurs="0"/>
>      </sequence>
>    </complexType>
>
> <complexType name="ECValidationDataType">
>  <sequence>
>    <element name="seed" type="ds:CryptoBinary"/>
>  </sequence>
>  <attribute name="hashAlgorithm" type="anyURI" use="required" [?] />
>  <attribute name="curveRandom" type="boolean"/>
>  <attribute name="pointRandom" type="boolean"/>
> </complexType>
>
> ... and remove the "seed" element from the curve type:
>
> <complexType name="CurveType">
>  <sequence>
>    <element name="A" type="ds:CryptoBinary"/>
>    <element name="B" type="ds:CryptoBinary"/>
>  </sequence>
> </complexType>
>
> The advantage of the above design would be that you gather all EC  
> validation data in a type of its own, and you will also be able to  
> express whether the verifiability is for the curve (curveRandom =  
> true), the point (pointRandom = true), both (both = true) or none  
> (that's when the ECValidationData element is not present at all).

Received on Monday, 23 February 2009 11:32:09 UTC