Explain Main In Middle Attack In Diffie Hellman Key Exchange

Subject: Information and Network Security

Semester: BE Computer Sem-7
Question: Main In Middle Attack In Diffie Hellman Key Exchange

Answer :

Suppose Alice and Bob wish to exchange keys, and Darth is the adversary.

1. Darth prepares for the attack by generating two random private keys XD1 and XD2 and then computes corresponding public keys YD1 and YD2.

2. Alice transmits YA to Bob.

3. Darth intercepts YA and transmits YD1 to Bob. Darth also calculates K2 = (YA)^XD2 mod q.

4. Bob receives YD1 and calculates K1 = (YD1)^XB mod q.

5. Bob transmits YB to Alice.

6. Darth intercepts YB and transmits YD2 to Alice. Darth also calculates K1 = (YB)^XD1 mod q.

7. Alice receives YD2 and calculates k2 = (YD2)^XA mod q.