I ask about represent message in Menezes–Vanstone elliptic curve cryptography I now encrypt function as follow
$C_1 = (M_1 * K_1) mod\ P$
$C_2=(M2 * k_2) mod\ P$
My question is about how much the size of $M_1$ and $M 2$, if we assume we are working on the 256 curve. Does the size of $M_1$ is one character and $M_2$ is also one character or $M_1$ is 32 byte and $M_2$ is 32 bytes. I hope anyone clarification about my problem.
I need any proposal.