As per my understanding, in Elliptical curve cryptography, the EC PrivateKey is nothing but a bigInteger value. If you know the curve specs and you have this private BigInteger value (which I am referring as raw private key), then you can re-create PrivateKey and use it for generating the signature.

Now, my question is, if you know the raw privateKey and curve name (aka specs), can you generate the corresponding public key?

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    $\begingroup$ Of course: If you know the curve $E$ and base point $P\in E$, the public key is simply computed as $Q=xP$ where $x\in\mathbb N$ is the private key. $\endgroup$
    – yyyyyyy
    Dec 11, 2015 at 14:37
  • $\begingroup$ Thanks, I found the answer later on after reading this crypto.stackexchange.com/a/15307/25460 $\endgroup$
    – ua741
    Dec 11, 2015 at 15:04
  • $\begingroup$ Shall we close the question as a duplicate of the linked one or do you (ua741) want a real answer (from @yyyyyyy ?)? $\endgroup$
    – SEJPM
    Dec 11, 2015 at 18:03
  • $\begingroup$ @yyyyyyy Can you please post your comment as an answer. $\endgroup$
    – ua741
    Dec 11, 2015 at 20:52
  • $\begingroup$ stackoverflow.com/questions/12480776/… is basically the same question with an answer specific to OpenSSL. $\endgroup$ Dec 12, 2015 at 2:33


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