1. Human-Computer Interface Course 2

2. Content The use of IT in everyday life Electronic Commerce Security Computer Viruses Copyright and the Law File Systems Working with the Computer

3. The use of IT in everyday life Can computers do anything ? NO ! –Computers cannot cook, invent, create, etc. –Computers help solving calculus intensive problems or large communication problems. Examples: –Airline ticketing systems. –Online banking –Online information indexing.

4. The electronic World Our world tends to become electronic by its nature. First we had the MAIL – than the E-mail Commerce struggled to develop during centuries - E-Commerce started in a few years.

5. E-Commerce – To be or not to buy ! Steps and procedures: –Target the merchandise –Give contact, shipping and billing information. –Proceed to payment –Wait for delivery –Attempt to return unsatisfactory goods – a basic right.

6. E-Commerce–To buy or not to buy ! Advantages: –24 hours/day service, extended range of products without changing physical location, etc Disadvantages: –Virtual store(one cannot use its senses), no human contact, risks at the payment level.

7. Security There is a potential data thief for every potential data store. Computers are data handlers and data stores. Need to make people aware about securing data in computer system or network. Secure data  Good Privacy Policy.

8. Security implementation Adoption of good password policies. Understand the difference between user ID and password. Define reasonable access rights policies. Encrypt sensible data. Protect against data corruption – backup.

9. Computer virus What is a computer virus ? –A piece of software that attaches to other programs in order to execute itself. Types of computer viruses: –Boot viruses and File Viruses –E-Mail viruses –Worms –Trojan horses

10. Who creates viruses and why ? People create viruses. Reasons –Psychology of Vandals –Destruction fascination –REVENGE –Challenge – defeat an existing system

11. How can a virus enter a computer system ? Floppy Disks and downloaded files (boot, executable files) E-Mail attachment (programs, scripts) Documents (Word, Excel) (macro viruses) Computer OS security holes (worms ) Network (worms ) Downloaded programs (FTP/WWW/BBS) (Trojan Horses)

12. Antivirus software Software that prevents and help disinfecting computers Facilities: infection prevention,disinfections, control of not allowed operations, live check. Limitations: unknown viruses, need to have up to date virus signatures. Examples: Norton Antivirus, RAV Antivirus, etc.

13. Avoiding virus infections Do not open e-mail attachments automatically without scan. Be circumspect with downloaded programs. Have an Internet Firewall Have an active Antivirus software installed

14. Virus Examples CRUEL – boot virus, infection-floppy. Melissa (’99) – e-mail virus, spread by sending copies to the first 50 entries in the address book. Code Red – worm – exploits Microsoft IIS Bad Sectors – application virus – infects DOS executable files. Trojan Horse – Melissa.

15. Computer Laws and Copyright Copyright - protects creative works from being reproduced, performed, or disseminated by others without permission. The owner of copyright has the exclusive right to reproduce a protected work; to sell or lend copies of the protected work to the public; Copyright - does not protect the idea or concept; it only protects the way in which an author has expressed an idea or concept. If, for example, a scientist publishes an article explaining a new process for making a medicine, the copyright prevents others from substantially copying the article, but it does not prevent anyone from using the process described to prepare the medicine. In order to protect the process, the scientist must obtain a patent.

16. Software protection Shareware – try and buy Freeware – use at your own will. License agreement - An End User License Agreement (EULA) is a legal contract between a software application author or publisher and the user of that application - a rental agreement; the user agrees to pay for the privilege of using the software, and promises the software author or publisher to comply with all restrictions stated in the EULA.

17. File Systems Disk storage and file systems – a disk organization method. Examples: –FAT, VFAT, FAT32 –EXT2, EXT3 –HPFS –NTFS

18. Hard Disks

20. Boot record of FAT16 FieldOffsetSizeDefault Jump03 OEM ID38MSWIN4.0 Bytes Per Sector112512 Sectors Per Cluster131See cluster sizes Reserved Sectors1421 FAT's1612 Root Entries172512/544 Sectors (small, for FDD)1920 Media Descriptor211See Media Descriptors Sectors Per FAT222Must be calculated Sectors Per Track242Depends on your HDD, see Appendix Heads262See above Hidden Sectors284 Sectors (large, for HDD)324Size of the partition, see Boot Process Physical Drive No.36180h Current Head3710 Signature381for WinNT: 28h or 29h Serial number (ID)394Random Volume Label4311 System ID (filesystem)548FAT12, FAT16, FAT, FAT32 Total62