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sol-hw3 - 3 Z intercepts the message sent from A to B Z...

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3-  Z intercepts the message sent from A to B. Z then sends B the message (Z, E B  (M), B).  B will answer Z according to the protocol by sending message (B, E Z  (M), Z). Z  can now decode E Z  (M) to find M. 4-  B can fool A by replaying him/her with same nonce N1. 1 . A → B: N1 2. B → A: N1 3. A → B: E K [N1] 4. B → A: E K [N1] 5-  Two situations arise, the first in which Eve, the attacker, does not send an initial message to Bob (steps 1 and 2), and the second where she does. In both scenarios, assume that Eve knows the session key k session , and has intercepted the message at step 5. Begin with the first case. Eve replays the message to Bob. As Bob has not yet received a new message from Alice (steps 1 and 2), he rejects the message. But if Eve’s message comes during Alice’s execution of the protocol and after step 2, Bob opens the message and determines the random number rand 3 . Because he kept track of the random number
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