1. Internet security for the home Paul Norton MEng(Hons) MIEE Electronic engineer working for Pascall Electronics Ltd. on the Isle of Wight A talk on Internet security from the viewpoint of the home user…

2. Profile of the Home internet user. Traditionally, home internet usage has tended to be:- Low bandwidth, billed per minute. Short DHCP lease time. For simple email, web access, chat. Increasing trends: Higher bandwidth, always-on, fixed fee. Longer leases. Multimedia email, filesharing applications, more complex chat programs, remote assistance, etc.

3. What do we mean by security? Keep private files private. Prevent damage to/tampering with our operating system and computer. Shop online safely. Send and receive email safely. Will not consider high-grade attacks in this talk.

4. Threats Viruses Backdoor programs Denial of Service (DoS) Interception

5. More about viruses Some viruses exploit software flaws to run automatically. Infection can come from a variety of sources Damage.

6. Klez Virus Klez-a detected by Sophos since Oct 2001. Top virus in 2002, still going strong. Auto executes Built-in mail engine. Attaches files randomly Attempts to disable AV. Also spreads via network.

7. Backdoor programs / trojans Program can do anything that a user sitting at the computer could do. Infection. DDOS.

8. DDOS attack

9. Methods of protection Anti virus Password discipline Firewalls

10. Passwords Storing passwords is risky. Passwords are recorded using a one-way function. Brute force attack.

11. Why firewall? To prevent the exploitation of backdoor programs. Prevent unauthorised connection to services. Prevents an attacker from scanning for a vulnerability

12. What does a firewall do? A firewall filters the network to allow only certain types of packets. Incoming connections. Obviously forged packets. ICMP danger.

13. Firewall examples Zone Alarm Smoothwall Iptables “Black box” firewalls.

14. Introduction to cryptography 2 main forms, symmetric, and asymmetric. Key verification. Session keys.

15. Shopping online SSL encryption (https) Key verification Cipher strength Weaknesses

16. Secure email Demo weaknesses. Digital signature. Encryption. SSL

17. Summary Backdoor programs and viruses pose threats Antivirus and firewalls reduce the risk. Traditional protocols may be unsafe. Cryptography can be used to provide secure communication.

18. Questions?

19. Server certificate

20. Basic introduction to Networking IP identifies each computer individually TCP identifies the service being used (www, ftp, email etc.) DHCP is used to assign an IP address to a computer upon connection to the internet