problem 1:

a) An opponent is using RSA with the public key {e = 53, n = 77}.  You intercept the ciphertext C = 10. (All values on this problem, comprising the ciphertext and the clear text, are numeric.)

i) Deduce p and q.
ii) Find out her private key.
iii) Determine clear text?

b) Define the terms ‘prime number’ and ‘prime factorization’. Describe the significance of prime numbers in the cryptography.

c) Consider cryptographic hash functions. Name four necessary properties for a cryptographic hash function, describing for each why it is vital.

d) describe the given methods used by firewalls to control the access:

• Packet Filtering
• Proxy Server
• Stateful Inspection

problem 2:

a) Describe in brief the following terms as used in the network security:

• Denial of service (DoS) attack
• Birthday attack
• DeMilitarized Zone (DMZ)
• Pretty Good Privacy (PGP) algorithm
• Social Engineering

b) List three advantages of using IPSec.

c) In brief describe the Cipher Block Chaining (CBC) mode of operation stating its benefits, drawbacks and uses.

d) In brief describe five guidelines for a desirable password selection and use policy in a corporate organization.