Internet Security

• What is the purpose of a firewall?

  To sit between trusted and untrusted networks
• What are the two types of inspection performed by firewalls?

  Stateless and stateful inspections
• How does stateless inspection work?

  Uses a list of IPs, ports, and protocols
• What is stateful inspection?

  Tracks open conversations in a connection table
• Why is stateful inspection generally more effective than stateless inspection?

  It checks packet payloads for suspicious activity
• What is the role of a proxy server?

  Provides privacy and web filtering features
• What is symmetric encryption?

  Uses the same key for encryption and decryption
• What is an example of symmetric encryption?

  Diffie-Hellman Key Exchange
• How does asymmetric encryption work?

  Uses a pair of public and private keys
• What is the advantage of asymmetric encryption over symmetric encryption?

  Provides higher confidentiality and authentication
• What is a digital signature used for?

  To authenticate the sender and guarantee integrity
• How is a digital signature created?

  By encrypting a hash of the message with the sender's private key
• What is a digital certificate?

  An electronic document verifying a sender's identity
• What information does a digital certificate include?

  Serial number, expiry date, holder's name, public key
• What is malware?

  Malicious software designed to harm devices
• What is a virus?

  Self-replicating software that attaches to programs
• How do worms spread?

  They replicate independently without a host program
• What is a Trojan?

  A malicious program disguised as legitimate software
• What does spyware do?

  Gathers information on a user without consent
• What is ransomware?

  Locks files and demands a fee for access
• What is the purpose of anti-malware software?

  To detect, quarantine, and remove malware
• How can code quality help protect against malware?

  Reduces bugs that malware can exploit
• What is the purpose of code reviews?

  To test and ensure code quality regularly
• What is patching in software?

  Updates designed to fix software vulnerabilities
• What are the types of malware and their characteristics?

  • Virus: Self-replicating, attaches to programs
  • Worm: Replicates independently, spreads without a host
  • Trojan: Disguised as legitimate software, malicious actions
  • Spyware: Gathers user information secretly
  • Ransomware: Locks files, demands payment for access
• What measures can be taken to protect against malware threats?

  • Use anti-malware/anti-virus software
  • Ensure high code quality
  • Conduct regular code reviews
  • Apply software patches for vulnerabilities