Implement A Function

Question

Group $G = Z_p^*$ Where $p$ is the order of $G$. $e$ is a funtion $e : G \times G \to G $ such that:

1. (Bilinear) For all $P,Q \in G$, for all $a,b \in Z$, $e(P^a,Q^b) = e(P,Q)^{ab}$.
2. (Non-degenerate) There exists some $P, Q \in G$ such that $e(P, Q)\neq 1$, where $1$ is the identity of $G$.

How to implement such function $e$ in Computer(Java)?

Thanks a lot!