Security

Question 1

(5 answers)

What are the different types of system attackers?

Answer 1

• Hackers
  
  • Keystroke logging, password harvesting, identity theft, etc.
• Click fraud
  
  • Pay-per-click charges to online advertisements that are generated fraudulently
• Bulk-mailers
  
  • Spam, phishing
• Employees, system users, members of the public
  
  • Through deliberate or unintended misuse
• Extortion
  
  • The suggestion that confidential data will be exposed

Question 2

(4 answers)

What are the different types of threats to systems?

Answer 2

• Interruption
  
  • Asset is unusable or unavailable when required (Denial of Service)
• Interception
  
  • Unauthorised party has gained some access to an asset
• Modification
  
  • Interception with alteration to an asset
• Fabrication
  
  • Creation of an unauthorised new object in the system

Question 3

(6 answers)

What are the different security services required by enterprise systems?

Answer 3

• Confidentiality
  
  • Assets are only accessible to authorised users
• Integrity
  
  • Malicious or accidental alteration of data is detected
• Non-repudiation
  
  • Users must be accountable for their actions (non-deniability)
• Auditing
  
  • A secure record of security-related events for the purpose of non-repudiation and recovery is captured
• Authentication
  
  • Users can be identified and actions are correctly associated with individuals
• Authorisation
  
  • Determines what a user or program is allowed to do

Question 4

(7 answers)

What are the different security policies an system administrator should employ?

Answer 4

• Passwords are changed regularly and are a certain length and complexity
• User accounts have no more privileges than required
• Regular cycle of system backups
• Enforce update/patch cycles
• Deploy virus protection and anti-spyware systems
• Install and configure a firewall
• Have users sign statements of legitimate use of computer resources

Question 5

What types of security measures can be taken to improve system security?

Answer 5

• Cryptography
  
  • Ciphers
    
    • Caesar
    • Rail-fence
    • Block
    • Stream
  • Symmetric cryptography
  • Public key cryptography
  • Hash functions
• Protocols and networking:
  
  • IPv6
  • SSL
  • Firewalls