snapshot 3:message block 'a' entered by sender Fig3: Message 0000000a(hex) is input and the corresponding values of X and Y are generated. Here, in this example we are just sending one block of message, so we go to the Coda part by pressing 1. snapshot 4:sender authenticator calculation Fig4: After pressing 1 for the Coda, two sets of values for X and Y are output, generated by the calculation done in the Main Loop on two numbers S and T. Finally, the authenticator, Z is calculated. Note: Z= XOR (X, Y), X and Y are the recent values taken. i.e. A9DEB9E5 XOR 58307F98 = F1EEC67D
References.