Alice and Bob use the Diffie-Hellman key exchange process to agree on a shared key. Eve (the eavesdropper, an adversary) knows the parameters p and a used by Alice and Bob, and is able to see all messages Alice and Bob sent and received during the process. Briefly explain why Eve is unable to determine the shared key.

Alice and Bob use the Diffie-Hellman key exchange process to agree on a shared key. Eve (the eavesdropper, an adversary) knows the parameters p and a used by Alice and Bob, and is able to see all messages Alice and Bob sent and received during the process. Briefly explain why Eve is unable to determine the shared key.

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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PLEASE FILL OUT THE CHART GIVEN BELOW Man-in-the-middle attack when Alice and Bob employ Diffie-Hellman key exchange. Alice Carol (Intruder) Bob p=17 and α= 4 are known to all Choose kpri,A =a = 7 Choose kpri,B =b = 8 Alice’s public key: kpub,A = A= αa mod p = Bob’s public key: kpub,B = B=αb mod p = Send A to Bob; intercepted by Carol Send B to Alice; intercepted by Carol Carol chooses c=6; computes A’ = B’ =αc mod p Carol sends A’ to Bob as if it is A from Alice Carol sends B’ to Alice as if it is from Bob Alice derives the shared secret key as K1= B’a mod p Carol derives K1= Ac mod p, K2= Bc mod p, Bob derives the shared secret key as K2= A’b mod p Session 1 established with key K1: verify that Alice and Carol have derived the same key K1 Session 2 established with key K2; verify that Carol and Bob have derived the same key K2
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