Overview

1. B.A. (Mahayana Studies)000-209 Introduction to Computer ScienceNovember 2005 - March 20069. Safety and Security What are the main safety and security issues when using computers? How can data/files be kept safe?

2. Overview • 1. Hardware Reliability • 2. Backing up your Data • 3. Computer Viruses • 4. Keeping Data Safe • 5. Internet Security 000-209 Intro to CS. 9/Secure

3. 1. Hardware Reliability • The reliability of a computer component is measured in MTBF (mean time between failures). • hardware is tested in a laboratory • number of failures is divided by total hours of observation • It’s better to plan for a hardware failure than hope one doesn’t happen. 000-209 Intro to CS. 9/Secure

4. Hardware Failure • Downtime- time when a computer is not functioning. • Hardwareredundancy (maintaining extra equipment) is a popular safeguard used by e-commerce sites. 000-209 Intro to CS. 9/Secure

5. Power Supply Problems • A power failureis a complete loss of power to the computer system. • data stored in RAM will be lost • A powerspike is a brief increase in power • less than one-millionth of a second • A powersurge lasts a little longer • Surges and spikes can damage computers. 000-209 Intro to CS. 9/Secure

6. Uninterruptible Power Supply • A UPS (uninterruptible power supply) is the best protection against power failures, surges, and spikes. A UPS contains a battery that keeps your computer running for several minutes during a power failure 000-209 Intro to CS. 9/Secure

7. Surge protector vs. Power strips • A surge stripcan protect your computer and other devices from power spikes and surges. • does not contain a battery continued 000-209 Intro to CS. 9/Secure

8. Don’t mistake a powerstrip for a surge strip • a power strip provides multiple outlets but cannot protect your computer from power spikes and surges 000-209 Intro to CS. 9/Secure

9. 2. Backing up your Data • Copying files, or the contents of am entire disk, provides the best security for your data. • Backup tips: • scan for viruses before backing up • make frequent backups (once a day/week) • check the backups • store backups away from your computer 000-209 Intro to CS. 9/Secure

10. What to Use for Backups • Consider capacity, speed, and reliability. 000-209 Intro to CS. 9/Secure

11. Backup Software Simply Safe Backup (free) http://www.simplysafebackup.com/ Norton Ghost 9.0 000-209 Intro to CS. 9/Secure

12. Full backup copy all the files safe but can take a long time Differential backup copy the files that have changed since the last full backup takes less time but more complex Incremental backup copy the files that have changed since the last backup Types of Backups 000-209 Intro to CS. 9/Secure

13. 3. Computer Viruses • A computer virusis a program that attaches itself to a file, duplicates itself, and spreads to other files. 000-209 Intro to CS. 9/Secure

14. Virus Warning Signs • The following signs might mean that your computer has a virus: • displays a rude, embarrassing message • unusual visual or sound effects • difficulty saving files • files mysteriously disappear • the computer works very slowly • applications increase in size for no reason 000-209 Intro to CS. 9/Secure

15. Virus Types • A boot sector virusinfects the system files that your computer uses. • A macrovirus infects a macro. • Macros are tiny programs used in word documents, databases, spreadsheets, and many other large applications 000-209 Intro to CS. 9/Secure

16. Most Popular Virus Types Macro viruses are the most common. 000-209 Intro to CS. 9/Secure

17. Computer Protection • Do not get files from high risk sources • Use anti-virus software 000-209 Intro to CS. 9/Secure

18. When a Virus Hits... • Don't: • E-mail any attachments from your machine • Ignore it, hoping it will go away • Do: • tell your system administrator • remove it using anti-virus software • keep anti-virus software updated 000-209 Intro to CS. 9/Secure

19. Anti-virus software Norton AntiVirus 2005 avast! 4 Home Edition (free) http://www.avast.com/ 000-209 Intro to CS. 9/Secure

20. Virus Detection Methods • Anti-virus software checks for a virus signature– a unique series of bytes that identifies a known virus inside another program. • Hackers keep making new viruses, with new signatures, so anti-virus software needs to be updated regularly. • usually automatically via the Internet 000-209 Intro to CS. 9/Secure

21. A Trojan Horse • A Trojan horseis a computer program that appears to do something good/useful while actually doing something bad. • not a virus, but may carry a virus • does not duplicate itself • Example: a free game available for download from an unknown Web site • it really deletes files once it is started 000-209 Intro to CS. 9/Secure

22. Bombs • Atime bombis a program that stays in your system undetected until it is triggered by a certain event in time. • e.g. on "Friday 13th" it deletes all your files • usually carried as a virus or in a Trojan horse • A Logicbomb is a program triggered by changes to your files. • e.g. every new Word file is deleted 000-209 Intro to CS. 9/Secure

23. Worms • A software wormis a program designed to enter a computer system through security holes in the computer network. 000-209 Intro to CS. 9/Secure

24. 4. Keeping Data Safe • Good habits: • save files frequently when you are working on them • backup files frequently • use anti-virus software • do not open documents with unknown macros 000-209 Intro to CS. 9/Secure

25. Acceptable Use Policy • Acceptable use policy- rules that specify how a computer system should be used • determined by management • used by large organizations • makes users aware of limits and penalties • provides framework for legal action 000-209 Intro to CS. 9/Secure

26. User Rights • User rights- rules that limit directories and files that each user can access. • erase rights • create rights • write rights • read rights • file find rights 000-209 Intro to CS. 9/Secure

27. Restrict Physical Access • Keep data backups in a locked room, away from the main computing area. • Offices with computers should be locked when there is no one around. • Computers can be chained to their desks. 000-209 Intro to CS. 9/Secure

28. Personal IDs • Personal identification help identify authorized users: • identity badges • user IDs and passwords • biometrics 000-209 Intro to CS. 9/Secure

29. Biometric Example Fingerprint scanners can confirm your identity in less than two seconds. 000-209 Intro to CS. 9/Secure

30. Encryption • Scramble information so it cannot be understood until it is decrypted. 000-209 Intro to CS. 9/Secure

31. 5. Internet Security and ActiveX • Many Internet security problems are due to ActiveX controls • developed by Microsoft to extend the power of Internet Explorer • ActiveX controls can be part of Web pages downloaded by Internet Explorer continued 000-209 Intro to CS. 9/Secure

32. ActiveX controls has full access to your computer. • hackers can use ActiveX controls to cause havoc • Digital certificatesidentify the author of an ActiveX control • controls with digital certificates should be safe, if you trust the certificate! • Internet Explorer can be configured to reject all ActiveX controls that do not come with certificates. 000-209 Intro to CS. 9/Secure

33. Electronic Commerce Security • Most e-commerce sites provide a secure channel for transmitting credit card data. • SSL (Secure Socket Layers) uses encryption to establish a secure connection. • SSL pages start with https instead of http. • S-HTTP encrypts data one message at a time. continued 000-209 Intro to CS. 9/Secure

34. Encrypted messages ensure that credit card numbers cannot be intercepted between a computer and an e-commerce site. During secure transactions, Internet Explorer displays a lock icon and Netscape Navigator displays a key icon. 000-209 Intro to CS. 9/Secure