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1. Re: Addition/ Scalar multiplication of Points on elliptic curves
925183 Mar 22, 2012 6:55 AM (in response to 925503)Hello,
The Javacard API contains the KeyAgreement object
inititialize with a ECPrivateKey and use the generateSecret function
unfortunatly the ALG_EC_SVDP_DH is contains a sha1postcomputation, so u dont get the sectet ECC point but a hash of it
you cannot get the resulting ECPoint with Javacard 2.2.2.
you might look up for jcopx which contains ALG_EC_SVDP_DH_PLAIN_XY which returns the direct values of ECPoint multiplication
Greetz, Paul 
2. Re: Addition/ Scalar multiplication of Points on elliptic curves
925503 Mar 22, 2012 2:05 PM (in response to 925503)thank you.
I think you mean
com.nxp.id.jcopx.KeyAgreementX;
which is part of the "NXP JCOP Tools".
Those "NXP JCOP Tools" seem to have restrichted Access or something.
talking to other Java Card developers, they told me its practically impossible to get this or any reply of NXP regarding this at all.
Just like posted here:
can't get JCOP tools
any other ideas or ideas how to get this class/tools ?! 
3. Re: Addition/ Scalar multiplication of Points on elliptic curves
925183 Mar 27, 2012 6:23 AM (in response to 925503)unfortunalty this is true
if you currently dont have jcop tools it will be very hard to get access :/
i dont know of any other way with java card 
4. Re: Addition/ Scalar multiplication of Points on elliptic curves
925503 Mar 29, 2012 4:39 PM (in response to 925503)Nice. So I have to implement all this manually  I'm quite curious how long this will take on GPcpu of the card. Especially doing an Extended Euclidian Algorithm.....
whats the reason to return SHA1hash only anyway?!...... 
5. Re: Addition/ Scalar multiplication of Points on elliptic curves
Adriaan Mar 30, 2012 4:42 AM (in response to 925503)922500 wrote:
Too long for practical purposes, I'd say. Is there any particular reason you need to do this on a card? Could you offload this step to a more capable platform?
Nice. So I have to implement all this manually  I'm quite curious how long this will take on GPcpu of the card. Especially doing an Extended Euclidian Algorithm.....
922500 wrote:
Previously discussed here:
whats the reason to return SHA1hash only anyway?!......
(Question)About.....ECDHKeyAgreement.ALG_EC_SVDP_DH
and here:
Re: CREF KeyAgreement.ALG_EC_SVDP_DH implementation
Adriaan 
6. Re: Addition/ Scalar multiplication of Points on elliptic curves
safarmer Mar 30, 2012 1:00 PM (in response to 925503)922500 wrote:
The problem with using the classes in the com.nxp packages is not with getting JCOP tools, but that it will only work on a JCOP SmartMX platform that has the required classes. This is a proprietary API to NXP JCOP cards and will not work on other platforms. If you are targeting JCOP cards specifically you may be able to use these classes. I am not sure where you would get the required class file to compile against and EXP file to convert your CAP file without JCOP tools though.
thank you.
I think you mean
com.nxp.id.jcopx.KeyAgreementX;
which is part of the "NXP JCOP Tools".
Those "NXP JCOP Tools" seem to have restrichted Access or something.
talking to other Java Card developers, they told me its practically impossible to get this or any reply of NXP regarding this at all.
Just like posted here:
can't get JCOP tools
any other ideas or ideas how to get this class/tools ?!
Cheers,
Shane 
7. Re: Addition/ Scalar multiplication of Points on elliptic curves
925503 Apr 2, 2012 2:07 AM (in response to 925503)well, it is part of my Bachelor thesis to do this multiplication on card. 
8. Re: Addition/ Scalar multiplication of Points on elliptic curves
925183 Apr 5, 2012 8:27 AM (in response to 925503)implementing EC curve operations by hand will take very much time for you and later on card computation will be VERY slow because you dont use the crypto procssor 
9. Re: Addition/ Scalar multiplication of Points on elliptic curves
925503 Apr 5, 2012 4:09 PM (in response to 925503)I know, but my advisor wants me to test it. Since there is no other possibility to do this on card, I'll do this. If this takes hours/days it does not say anything about this beeing practically useable, of course. I really dont know why common JavaCardAPI can return a hash only?!.....