1. List some of the attacks on the Diffie-Hellman key exchange protocol. Present your solution for avoiding such attacks.
2a. In the Diffie-Helman protocol, g=7, p=23, x=3, and y=5.
i) What is the value of the symmetric key?
ii) What is the value of R1 and R2?
Variations of data
1) g=5, p=19, x=7, and y=3
2) g=11, p=31, x=3, and y=9
3) g=7, p=43, x=2, and y=7
b. In the Diffie-Helman protocol, what happens is x and y have the same value, that is, Alice and Bob accidentally chosen the same number? Are R1 and R2 same? Do the session key calculated by Alice and Bob have the same value? Explain what would adversary observe? Could she guess Alice's and Bob's private key? Use an example to prove your claims.
c. Suppose Fred sees your RSA signature on m1 and m2, (i.e., he sees (m1d mod n) and (m2d mod n)). How does he compute the signature on each of m1j mod n (for positive integer j), m1-1 mod n, m1 x m2 mod n, and in general m1j m2k mod n (for arbitrary j and k)?© BrainMass Inc. brainmass.com October 16, 2018, 9:29 pm ad1c9bdddf
This response discusses attacks on the Diffie-Hellman key exchange protocol.
Authentication protocol is modeled.
Suppose we are using a three-message mutual authentication protocol, and Alice initiates contact with Bob. Suppose we wish Bob to be a stateless server, and therefore it is inconvenient to require him to remember the challenge he sent to Alice. Let's modify the exchange so that Alice sends the challenge back to Bob, along with the encrypted challenge. The protocol is: (It is shown in the image attached)
Is this protocol secure? Justify your answerView Full Posting Details