2
$\begingroup$

In SEC 2: Recommended Elliptic Curve Domain Parameters curve secp112r1 has $0xDB7C2ABF62E35E668076BEAD208B$ as the order of the finite field and as the $a$ coefficient in the equation $y^2 =x^3 +ax +b$. Wouldn't that essentially make the $a$ coefficient $0$? If so then why not just say that that's what the coefficient is?

secp192k1 has $0$ as coefficients so it's not like there's not precedent for a coefficient of $0$.

$\endgroup$
5
$\begingroup$

You misread the parameters: $p$ is $$\mathrm{0xDB7C2ABF62E35E668076BEAD208B} \text,$$ but $a$ is $$\mathrm{0xDB7C2ABF62E35E668076BEAD208\underline{\mathbf8}}$$ which is $-3$ $\bmod p$!

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.