message amount
1.When a message is encrypted in (H)ECC, there will be a large amount of message expansion. Due to this fact, (H)ECC is often applied in Diffie-Hellman key agreement protocols and digital signature schemes, though ECC encrypting cards have appeared but only devised for some special kind of small data area. In the application of hyperelliptic curve cryptosystems, the key operation is divisor scalar multiplication.
