1. Unit 1.6 Systems security Lesson 4

2. This lesson covers the following from specification 1
This lesson covers the following from specification 1.6 System Security:
Forms of attack
Threats posed to networks:
Malware
Phishing
People as the weak point in secure systems (social engineering)
Brute force attacks
DDOS
Data interception and theft
SQL injection
Poor network policy
Identifying and preventing vulnerabilities
Penetration testing
Network forensics
Network policies
Anti-malware software
Firewalls
User access levels
Passwords
Encryption

3. Key Words
User access levels
Passwords
Encryption
Cipher
Key

4. Big Picture What are the benefits of encryption?
Why should passwords be kept secure?
Discuss with a neighbour: What things can we do to make sure our passwords are secure? List as many things as you can think of.

5. Learning Objectives
To understand the effects of user access levels on a system
To understand how and why passwords must be kept secure and the levels of complexity
To learn how encryption can have a negative effect on law enforcement and investigations
To understand how encryption works
To demonstrate a knowledge of a cypher and its’ key.

6. Engagement Activity What makes a secure password?
Build a list of suitable requirements for secure passwords
Create a list of rules for keeping a password secure
Explain why passwords should be kept secure in such a way.

7. User access levels Also known as system access rights
Comes under system access control
Allows a system administrator to set up a hierarchy of users
Lower level users would have access to limited information and settings
Higher level users can access the most sensitive data on the system

8. Activity 1 Complete Worksheet 1
Define a set of user access levels for various groups.

9. Passwords
Typically a string of characters used to gain access to a service or system
Discussion point:
Are there any alternatives to character password entry (eg. Biometrics?)
Research the Samsung Galaxy 8 – what security features does this device have to replace passwords?

10. Biometric security
Can be used in addition to ‘standard’ password entry (via a keyboard)
Examples include:
Retina scan
Fingerprint
Voice
Facial recognition
Benefits of using biometrics?

11. Secure or Strong Passwords
12 characters or more
The greater the characters, the stronger the password
Mixture of capitals, lower case letters, numbers and symbols
Short Exercise:
Create some easy passwords that are NOT secure?
How would you make them stronger?
e.g. password123  Passw0rd123!

12. Protecting password-based systems
Systems that use passwords often prevent against people guessing passwords non-stop (brute force) by applying rules:
The time gap between entering one password and another
e.g. mobile phones lock for 30 seconds after a number of incorrect attempts
Limits to the number of password guesses
After which the account becomes “locked” and needs Admin access
Complexity requirements of passwords
You can only use secure passwords when setting up your account
Try creating a new account on a website and many have “password strength” indicators
Password encryption
Password reset policies
You are forced to change your password at certain times (e.g. every 30 days)

13. Activity 2
Create an infographic to illustrate the importance of secure passwords
Explain the elements of a secure password
Piktochart.com

14. Encryption
Where data is translated into code so that only authorised users, or users with the key can decrypt it
Users must need the key in order to decrypt the coded file

15. Encrypted messages
Reading:
What effect would Whatsapp’s encryption policy have on British police and other security investigations?

16. Method of encryption – Caesar Cipher
Cipher invented by Julius Caesar
Designed to keep his messages secret
Works by encrypting messages through movement of each letter a certain number of places to the left in the alphabet
Key tells us how many places to the left the letters have been moved.

17. Method of encryption – Caesar Cipher
Let’s say we received the message ABZOVMQBA with and the key was 3.
The decrypted message would read decrypted A B Z O V M Q D E C R Y P T

18. Activity 3 Caesar Cipher Use template in order to write a message
Swap with a partner to decrypt the message
Base the groups on ability – lower ability = smaller key shift, smaller messages.

19. Plenary Post-it activity (small groups / pairs)
Recall elements of a secure password in groups
Create a secure password and explain reasons for it being secure
Define user access levels for a librarian in a library
If time permits, set Ceaser Cipher group task with complex key shift

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