I have a smart card which supports JavaCard 2.2.2 and I would like to develop a signature with tickets on elliptic curve. To do that, I need to compute the sum of 2 points on an elliptic curve. I've read the JavaCard's API and I don't think it is possible, in fact there are things about elliptic curves but only for algorithms that are already developed (ECPrivateKey for ECDSA for example ...) But when you want to create an ECPrivateKey, you have to give the parameters which define the elliptic curve, so it is defined somewhere, right ?
To put it in a nutshell, is it possible to develop a Java cardlet which makes computation (sum, product of points...) over an elliptic curve ?
I am a little bit lost aboutthis so thank you very much for your help :)
No, it is not currently possible with the standard Java API, at least not without doing all the required computations yourself, which would require a lot of complex code and the implementation of a multiplier (which will not perform well).
It may just be present in some proprietary API's though (such as certain versions of JCOP, to name a completely random example).
Update: 3.0.5 contains ALG_EC_PACE_GM. That still not point addition, but it can be used to implement PACE without proprietary extensions. If the card implements the algorithm in the first place, of course.