Acceleration of a pairing calculation of an Ate-based pairing such as Optimal Ate pairing depends not only on the optimization of Miller algorithm’s loop parameter but also on efficient elliptic curve arithmetic operation and efficient final exponentiation. Some recent works have shown the implementation of Optimal Ate pairing over Kachisa- Schaefer-Scott (KSS) curve of embedding degree 18. Pairing over KSS curve is regarded as the basis of next generation security protocols. This paper has proposed a pseudo 12-sparse multiplication to accelerate Miller’s loop calculation in KSS curve by utilizing the property of rational point groups. In addition, this papers has showed an enhancement of the elliptic curve addition and doubling calculation in Miller’s algorithm by applying implicit mapping of its sextic twisted isomorphic group. Moreover this paper has implemented the proposal with recommended security parameter settings for KSS curve at 192 bit security level. The simulation result shows that the proposed pseudo 12-sparse multiplication gives more efficient Miller’s loop calculation of an Optimal Ate pairing operation along with recommended parameters than pairing calculation without sparse multiplication.