you can use as the decryption exponent \(\displaystyle d\).

(That is for every \(\displaystyle M\in\{0,\dots,pq-1\}\), after encryption \(\displaystyle M\) using encryption exponent \(\displaystyle e\), and then by using the decryption exponent \(\displaystyle d\) we get back the \(\displaystyle M\)).

Thank you for all helpful answers. (Wink)