Computer Studies
End-of-Year Questions (2nd year-summer)
What is the Web? Who created it? What are the main components of the Web? (Возможно, не раскрыт третий вопрос про компоненты Web)
The World Wide Web, Web or WWW is a network of documents that works in a hypertext environment, i. e. using text that contains links, hyperlinks to other documents.
Tim Berners-Lee created Web.
The files, web pages, are stored in computers, which act as servers. Your computer, the client, uses a web browser, a special program to access and download them. The web pages are organized in websites, groups of pages located on the Web.
Describe how a browser finds the webpage you want. (лучше уточнить последовательность пунктов, см. №8 (b) в Unit 4)
Click on webpage hyperlink or URL.
The browser sends the URL to a DNS server.
The DNS server finds the IP address of the URL Web server.
The DNS server sends the IP address to the browser.
The browser uses the IP address to request the webpage.
The browser sends the request in series of data packets via router.
The Web server puts the packets together again.
The Web server sends the requested page to the browser computer in the same way.
The router determines the best route for each packet.
The browser combines the packets to form the page.
What features make a good website?
Well Designed and Functional
Simple and clear navigation
Ease of use
Fresh, Quality Content
Helpful graphics
What do you need to take into account when you plan your website?
Site’s purpose
The target audience
Look, feel and content will the site have
How will the site be created, rolled out and managed?
Efficiency of site
Speak about most common internet crimes. (scam, phishing, salami shaving) What is a cracker? What is a white hat hacker?
Scam – email fraud to obtain money or valuables.
Phishing – bank fraud, to get banking information such as passwords of Internet bank accounts or credit card details.
Salami shaving – manipulating programs or data so that small amounts of money are deducted from a large number of transactions or accounts and accumulated elsewhere. The victims are often unaware of the crime because the amount taken from any individual is so small.
Cracker, or black-hat hacker, is computer criminals who use technology to perform a variety of crimes: virus propagation, fraud, intellectual property theft, etc.
A white-hat hacker is a hacker who helps organizations protect themselves against criminal hackers.
What is hijacking, software piracy, mail bombing, denial of service attack and software piracy?
Hijacking – redirecting anyone trying to visit a certain site elsewhere.
Software piracy – unauthorized copying of a program for sale or distributing to other users.
Mail bombing – inundating an email address with thousands of messages, thereby slowing or even crashing the server.
Denial of service attack – swamping a server with large numbers of requests.
What is malware? Speak about different types of malware. (viruses, worms, Trojan horses, spyware)
Malware (malicious software) is software created to damage or alter the computer data or its operations.
Viruses are programs that spread by attaching themselves to executable files or documents. When the infected program is run, the virus propagates to other files or programs on the computer.
Worms are self-copying programs that have the capacity to move from one computer to another without human help, by exploiting security flaws in computer networks.
Trojan horses are malicious programs disguised as innocent-looking files or embedded within legitimate software.
Spyware, software designed to collect information from computers for commercial or criminal purposes, is another example of malicious software. It usually comes hidden in fake freeware or shareware applications downloadable from the Internet.
What tips can you give to prevent crackers’ attacks?
Don't open email attachments from unknown people; always take note of the file extension.
Run and update antivirus programs
Install a firewall, a program designed to prevent spyware from gaining access to the internal network.
Make backup copies of your files regularly.
Don't accept files from high-risk sources.
Avoid giving credit card numbers.
Don't believe everything you read on the Net.
What is a computer virus? How are computer viruses like biological viruses? What parts does a virus contain?
Viruses are programs that spread by attaching themselves to executable files or documents.
A biological virus is a very small, simple organism that infects living cells by attaching itself to them and using them to reproduce itself. Similarly, a computer virus is a very small program routine that infects a computer system and uses its resources to reproduce itself.
Viruses can have four main parts. A misdirection routine that enables it to hide itself; a reproduction routine that allows it to copy itself to other programs; a trigger that causes the payload to be activated at a particular time or when a particular event takes place; and a payload that may be a fairly harmless joke or may be very destructive.
What does data encryption provide? What is public-key cryptography? What is MAC?
Data encryption provides privacy.
Today's data encryption methods rely on a technique called public-key cryptography. Everyone using a public-key system has a public key and a private key. Messages are encrypted and decrypted with these keys. A message encrypted with your public key can only be decrypted by a system that knows your private key. For the system to work, two parties engaging in a secure transaction must know each other's public keys. Private keys, however, are closely guarded secrets known only to their owners.
Message-authentication code (MAC) is a a number, which produced a message-digest function to provide message integrity.
Speak about two hacking cases which you read about. What happened to the hackers in the end? (моя отсебятина в пункте 2, см. свой №33 в Unit 5 или тексты в №26)
In March 2000, a Welsh teenager allegedly stole information from more than 26,000 credit card accounts across Britain, the US, Japan, Canada and Thailand, and published the details on the Internet. FBI agents and British police raided the home of Raphael Gray,18, and arrested him and his friend. He has been charged with 10 counts of downloading unauthorized information.
Modest intellectual from St. Petersburg Vladimir Levin in 1994 hacked into the internal network of Citibank. He withdrew $10.7 million from the accounts of the bank's corporate clients and sent them to accounts located in the US, Israel, Germany and other countries. The hacker was arrested in London in March 1995 and later sentenced to three years in prison. He also had to pay a fine.
Speak about 4 strategies of converting to a new computer system. Explain their advantages and disadvantages. (моя отсебятина, см. свой №11 в Unit 6, если моё не устраивает)