Does anyone know some good online calculator or tool that can do a ECDH key agreement cross-check? I want to using the same test vector to do cross-check test with my code.
I find this on-line tool is good, but it only supports some of ECC curve... I would need support secp256k1 curve as well., which I can not find good tool yet. http://www-cs-students.stanford.edu/~tjw/jsbn/ecdh.html
On the page at http://www-cs-students.stanford.edu/~tjw/jsbn/ecdh.html, the buttons under 'Elliptic Curve Parameters' simply populate the textboxes for Curve Q, Curve A, Curve B, etc. with the predefined parameters for the selected curve.
There is no button for secp256k1, but you can manually simply copy & paste the parameters for secp256k1 (in decimal form), as follows:
Curve Q: 115792089237316195423570985008687907853269984665640564039457584007908834671663
Curve A: 0
Curve B: 7
Gx: 55066263022277343669578718895168534326250603453777594175500187360389116729240
Gy: 32670510020758816978083085130507043184471273380659243275938904335757337482424
N: 115792089237316195423570985008687907852837564279074904382605163141518161494337
The values above were taken from https://en.bitcoin.it/wiki/Secp256k1 and converted to decimal form.
