Algorithm 2: $sendMessage$ (A, B, m, K)

Input: Sender node A, receiver node B, message m and mutual key K

Output: True if the message sending operation completed successfully, otherwise return false

/* perform encryption operation                          */

$m^e\leftarrow$ extract control part from m and encrypt the control part using K; Finally merge the encrypted control part with the message m

/* Node A transmits the encrypted message to node B, where B receives it and decrypts the control part                                 */

/*$\phantom{(}$ If B receives the message successfully then return a positive acknoledgment

*/

$ret\leftarrow transmit(A,m^e,B)$

return $ret$