Web Development

Web Development

Week 7 Homework

July 16, 2012



1. Explain the four goals associated with computer threats.

    • Data Confidential- is keeping secret data secret.

    • Data Integrity- unauthorized users not allowed to modify data without owner’s permission.

    • System Availability- no one can disturb system making it unusable.

    • Privacy - protecting individual from misuse information about them.



2. Explain the main difference between Secret-Key Cryptography and Public-Key Cryptography.

Secret-Key Cryptography the key is private and with Public-Key Cryptography the key is public.



3. What is the digital signature?

A technology used to associate a users’ identity to a public key, in which the user’s public key is digitally signed by a trusted third party.



4. What is packet sniffer?

Is a software that examines all incoming and outgoing network packets looking for certain patterns.







5. Explain the various types of attacks from inside listed in section 9.5 of the text.

1.) Logic bombs - piece of code in a production system that clears disk, erases files at random, making hard-to-detect changes to key programs or encrypting essential files

2.) Trap door - Code inserted into computer system that allows hackers to bypass the entire authentication process.

3.) Login in spoofing - A phony copy of a system login system used to obtain user id’s and password



6. Explain the difference between a virus and a worm?

Virus attach to files and spread in a system when transferring effected files, self-replicate on a local computer and inserts harmful code into files.

Worm uses the network to travel from one computer to another and self-replicate between computers on the same network.





Chapter 9 Research Assignment

Three Viruses:

1.) Stuxnet virus was discovered on June 2010, targets Siemens industrial software and hardware through Microsoft Windows in Iran.   The virus targets supervisory...

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