PPT Slide
Let agent1 send a message j to agent2. Unless he gets a confirmation y1 = K2j he doesn㦙 know whether j has been received.
t0 : agent1 sends the original j to agent2.
t1 : agent2 receives j and sends back y1 = K2j .
t2 : agent1 receives y1 and sends y2 = K1K2j .
tx : yx-1 received and yx sent.
The delay e between any tx and tx+1 is unknown.