- h^*)$, where $a = g^\alpha$ and $b = g^\beta$; and let $h^* =
- H(g^{\alpha\beta})$. $A$ must decide whether $h = h^*$. Clearly, if $A$
- never queries $H$ at $(g^\beta, g^{\alpha\beta})$ then its advantage is
- zero, since it has no information about $h^*$.
+ h)$, where $a = g^\alpha$, $b = g^\beta$ and $h$ is some string in $\{0,
+ 1\}^k$; and let $h^* = H(g^\beta, g^{\alpha\beta})$. $A$ must decide
+ whether $h = h^*$. Clearly, if $A$ never queries $H$ at $(g^\beta,
+ g^{\alpha\beta})$ then its advantage is zero, since it has no information
+ about $h^*$.