Data Security 1 Exercises

1. Data Security 1 Exercises

2. Reading 3

3. Reading 3 • To transfer program control to the virus. • The Misdirection, Reproduction, Trigger and Payload routines. • It returns control to the program as originally written.

4. Reading 5

5. Reading 5 • They reproduce inside a host which they damage or destroy. • It can copy itself into any program files. • They can stay dormant in the memory until triggered. • Displaying a message on the monitor screen or deleting files on the hard disk. • COM or EXE programs. • 1c 2b 3d 4a • A Trojan has a payload but no reproduction routine.

6. Language Work 6

7. When a dismissed employee's name is deleted from the company’s payroll, a logic bomb is activated which causes the payroll records to be destroyed. • When a certain date occurs, a trigger routine is activated which makes keys beep when pressed and corrupts floppies. • When the hundred and twenty-ninth time, a trigger routine is activated which causes the screen to display, ‘Bloody! June 4, 1989’. • When the infected program is run, the boot sector is corrupted which causes the disk content to be overwritten and data to be lost.

8. Language Work 7

9. A MIDI message encodes sound as 8-bit bytes of digital information. • The teacher is using a new program to encourage children to write stories. • The new version of SimCity has been enhanced in many ways. • A gateway enables dissimilar networks to communicate. • You can encrypt data to make it secure. • Ensure the machine is disconnected before you remove the case.

10. Problem Solving 8

11. Problem Solving • F • H • C • A • E • G • B • D • J • i

12. Specialist Reading

13. Specialist Reading – Part A • A • C • Public-key cryptography. • Decrypt. • B • Information about the company operating the server and the server’s public key.

14. Specialist Reading – Part B • 1) a-iv b-iii c-i d-ii • 2)a-iii b-iv c-vi d-i e-ii f-v • 3)a-F b-T c-F d-F e-F f-F g-T h-T • 4) c,d,b,a