1

I have an ECPoint object "pointW" that I would like to check for whether it actually lies on some EllipticCurve "curve". How can I do this? I would prefer a solution using Java Crypto API but Bouncy Castle would also be fine. Thank you!

Thomas Lieven
  • 371
  • 4
  • 14

1 Answers1

2

There might be a more straightforward way but if you've got the EllipticCurve object, you can always just substitute the coordinates of your point into the equation of the curve.

biziclop
  • 48,926
  • 12
  • 77
  • 104
  • There is so much functionality - especially BC provides many checking and conversion methods - that I thought there had already to exist a method like this and I didn't feel like re-coding the wheel. I finally ended up doing as you suggested and it turned out to be much less effort than I had expected. – Thomas Lieven May 02 '14 at 14:23
  • @Thomas- Am trying to check the same whether Qc(Public key) is on curve p-256 or not. I got the EC from public but how to validate, could pls share api in java. EllipticCurve ec = publicKey.getParams().getCurve(); – Pand005 Nov 05 '19 at 15:36