Hello, I was able to sign my message using the ECDSA 256 function from openssl: ECDSA_SIG *signature = ECDSA_do_sign( &message[0], message_length, eckey); And the sign is verified to be valid also. And my question is about the compression of the signature. I understand that the signature has an r value and an s value. And there is a way to compress the r value to a temporary elliptic curve point R. And the value of curve point R is dependent on the LSB of the y-coordinate somehow. So does anyone know how to go from (r, s) to a compressed (R,s) in openssl? Thank you very much.
Regards, Chuong D. Khuc
