Home » Unit 32 Networked Systems Security » Week 6 – Methods of protecting networked systems

Week 6 – Methods of protecting networked systems

Rationalise the choice of symmetric and asymmetric encryption algorithms

Explain how a symmetric key can be shared across a network using asymmetric encryption

Describe the purpose of a public shared key

Identify the weaknesses of symmetric and asymmetric encryption algorithms



Last week we looked at Intrusion Detection Systems, can you explain the difference between an IDS and a IPS?
What is a low interaction honeypot?



Cryptography is about encrypting and decrypting data. With encryption, you take a piece of plain text (regular text that’s human readable) and then run an algorithm over it. The resulting data looks like a random byte sequence, often called ciphertext. Decryption is the opposite process: The byte sequence is transformed into the original plain text data. In cryptography, you can keep your algorithm secret, or you can use a public algorithm and keep your key secret.


Frequency analysis broke the Ceaser Cipher and lead mathematicians to study the unique properties of primary numbers using modular arithmetic.



Choosing an algorithm - ties into the next assignment.





Assignment task
Now that you have identified and discussed the ways in which a network can be targeted it is your job to explain the methods that can be used to defend Cyberdyne network systems.  Create a blog page and explain how the following methods can help or how they can be protected.

  • Email (the systems and the messages)
  • Wireless Networks
  • Network Devices such as Routers and Switches
  • Transmission Media (the wires)
  • Data and Privacy using Encryption


We started covering this task in week 4.

email systems:

  • secure MIME
  • spam
  • hoaxing
  • relay agents

wireless systems:

  • site surveys
  • MAC association
  • WEP/WPA keys
  • TKIP

wired transmission media

personal access control:

  • biometrics
  • passwords https://www.ncsc.gov.uk/guidance/password-guidance-simplifying-your-approach
  • usernames
  • permissions
  • digital signatures

device security access control:

  • protocols
  • log in
  • certificates


Assignment brief
Guidance for the network attacks or breaches task.