$1\mathrm{.}2$ One possible fictional mode, DrD Mode, takes a key, K$,$ and Initial Value, IV$.$

Ci$=$EKi$($Mi$)$ where K$0$is K and Ki$=$ K $(($IV $+$ i $)$ mod $264)$ for a $64-$bit block cipher.

Draw the block diagram of DrD$\text{'}$s mode showing encryption of $3$ blocks and another showing their decryption.