To achieve the same level of security, hyperelliptic curve cryptosystems (HCC) use a smaller field than elliptic curve cryptosystems (ECC). HCC has a more potential application to the product that has limited memory and computing power, for instance Smart cards. We discussed how to represent the domain parameters of HCC in a compact way. The domain parameters include the field over which the curve is defined, the curve itself, the order of the Jocobian and the base point