Given:
We have a principal $A$ that believes that $fresh(K_A)$ and $fresh(K_A^{-1})$, where $K_A$ and $K_A^{-1}$ are a public and private key pair generated by $A$.
$A\ believes\ B\ said\ \{X\}_{K_A}$
Is it possible to derive that $X$ is also fresh, and if so, how ?
Thank you.