AP Computer Science Principles: Internet Exam | 71 Questions And Answers!!

How are domain names and IP addresses related? - People use domain name to visit websites, and computers translate those domain names into IP addresses to locate and send data How can floating points lead to round-off errors? - Floating points round off the last digits of a infinite/large number, which can cause a rounding that might be incorrect when manipulated (e.g. 1/3=0.3333, but when multiplied by 3, it states 0.99999 and not 1) How can number storage limitation cause overflow errors? - Certain programs limit how many numbers they can store (e.g. if limit is 4 bits, then storage goes up to 1010). After a number that is long enough goes over the limit, it causes overflow, which returns an overflow error (e.g. infinity or NaN) How does a DDOS attack work? - Distributed Denial of Service attack: Hacker uses virus to take control of MANY computers. The infected network is called a botnet. The attacker then launches DOS attack from the infected computers (called zombie computers) to crash a website How does a one-time pad work? - Each message is encoded with a new key only used one time How does a substitution cipher work? - Each letter has a unique symbol (not just other letters) How does Internet redundancy impact fault tolerance and scalability? - (1) It impacts fault tolerance (the ability to work around problems) by increasing the number of possible pathways. (2) It increases scalability (ability to function even as size changes) by making the internet more expansive to more devices and people How does one know is SSL/TLS is active on their browser? - There would be a lock sign next to the URL How does sending information on web browsers work? - (1) Input information (like google search or login)(2) Information sent in HTTP "post" request (3) Goes to domain name server (4) Pertaining data sent back (5) In returning data cookie is attached for website to remember user (6) Next time server logs on when he sends information the cookie will be attached so domain server will know who it is How does the Caesar Cipher work? - An algorithm that shifts the message by a certain number How is the Internet designed to be redundant? Why? - There are multiple pathways among the physical connections of the Internet; If one or more pathways break down, there would still be another way to transmit a message from sender to receiver