AP Computer Science Principles Final Exam 2018-2019

Which of the following most accurately describes Moore's Law:

A. Moore's Law describes a relationship of boolean logic statements involving AND and OR

B. Moore's Law is the principle that one should assume that any traffic on the Internet is insecure

C. Moore's Law is the observation that computing power tends to double every two years

D. Moore's Law explains why cracking modern cryptography is a "computationally hard" problem

C

Fill in the blank of the following statement: "______ encryption is a method of encryption involving one key for both encryption and decryption."

A. Symmetric

B. Asymmetric

C. Public key

D. SSL

A

A coffee shop is considering accepting orders and payments through their phone app and have decided to use public key encryption to encrypt their customers' credit card information. Is this a secure form of payment?

A. No, public key encryption allows the credit card information to be read by the public.

B. No, the internet protocols are open standards and thus everything sent over the internet is sent "in the clear".

C. Yes, public key encryption is built upon computationally hard problems that even powerful computers cannot easily solve.

D. Yes, public key encryption is secure because it transmits credit card information in binary.

C

Pick the two expressions involving the Modulo operation that compute to the exact same value (choose 2)

A. 9 MOD 8

B. 1 MOD 16

C. 52 MOD 32

D. 9 MOD 64

A & B

Which of the following statements best describes the properties of public key encryption?

A. Public key encryption is an encryption method which relies on separate keys for encrypting and decrypting information.

B. Public key encryption is a highly secure encryption scheme that in which a single shared key is used by both the sender and receiver of the message.

C. Public key encryption makes use of certain types of problems which are easier for humans to solve than computers.

D. Public key encryption makes use of mathematical problems which no algorithm can be used to solve.

A

Choose the answer that is NOT a feature of Public Key Cryptography:

A. A key for decrypting is never made public

B. Using public key guarantees that only the intended recipient can decrypt the message

C. A Public Key database ensures 3rd party accountability of security

D. Allows secure communication without establishing a shared encryption key ahead of time.

C

What is a Distributed Denial of Service (DDoS) attack?

A. A coordinated effort by a group to simultaneously attempt to gain entry to foreign government's servers or systems

B. An effort by network engineers to focus all systems on catching a user or computer that has illegally gained access.

C. An attempt to compromise a single target by flooding it with requests from multiple systems.

D. An attempt to harass or extort all customers of one or more Internet Service Providers (ISPs).

c

A programmer is writing a system that is intended to be able to store large amounts of personal data. As the programmer develops the data system, which of the following is LEAST likely to impact the programmer's choices in designing the structure of the system?

A. Maintaining privacy of the information stored in the data set.

B. Scalability of the system.

C. Structuring the metadata of the information for analysis.

D. The frequency of a particular item occurring in a data set.

D

Which of the following are true statements about digital certificates in Web browsers?

I. Digital certificates are used to verify the ownership of encrypted keys used in secured communication

II. Digital certificates are used to verify that the connection to a Web site is fault tolerant.

A. I only

B. II only

C. I and II

D. Neither I nor II

A

Which of the following scenarios is most characteristic of a phishing attack.

A. You accidentally run a piece of code that automatically spreads from one computer to another, exploiting a common vulnerability

B. You get an email from the IT support desk that asks you to send a reply email with your username and password to verify your account

C. You get an unwanted email trying to sell you a low quality product or service that seems "fishy."

D. You accidentally install a piece of software that monitors your activity to steal personal information like your passwords, date of birth, social security number, etc.

B

Big Data

the huge and complex data sets generated by today's sophisticated information generation, collection, storage, and analysis technologies

Moore's Law

The number of transistors per square inch on an integrated chip doubles every 18 months

One-pager

a one-page document that summarizes a large issue, topic or plan.

Caesar Cipher

a technique for encryption that shifts the alphabet by some number of characters

cipher

code

Cracking encryption

an attempt to decode a secret message without knowing all the specifics of the cipher

Decryption

The process of converting a ciphertext into plaintext

Encryption

A standard method for encoding data.

Random Substitution Cipher

an encoding technique that maps each letter of the alphabet randomly to different letters or characters.

Computationally Hard

a "hard' problem for a computer is one in which it cannot arrive at a solution in a reasonable amount of time.

asymmetric encryption

two keys are used; one key encodes the message, and the other key decodes the message

modulo operator

finds the remainder after division of one number by another

private key

In an asymmetric encryption scheme the decryption key is kept private and never shared, so only the intended recipient has the ability to decrypt a message that has been encrypted with a public key.

Public Key Encryption

Used prevalently on the web, it allows for secure messages to be sent between parties without having to agree on, or share, a secret key. It uses an asymmetric encryption scheme in which the encryption key is made public, but the decryption key is kept private.

Symmetric Encryption

the same key is used to encode and decode

antivirus software

scans hard drives to prevent, detect, and remove known viruses, adware, and spyware

DDoS Attack

Hacker floods a server with numerous bogus requests through numerous zombies so that legitimate users can no longer access the server

Firewall

Part of a computer system that is designed to block unauthorized access

Phishing Scam

A scam where someone tries to deceive you into providing personal information by impersonating someone

SSL/TLS

Secure Sockets layer / Transport Layer Security - An encryption layer of HTTP that uses public key cryptography to establish a secure connection.

Virus

A piece of code that is capable of copying itself and typically has a detrimental effect, such as corrupting the system or destroying data

Callback function

A function that is triggered by another function when something is true.

event

anything that happens or is regarded as happening

Event-driven program

a program designed to run blocks of code or functions in response to specified events (e.g. a mouse click)

Event handling

an overarching term for the coding tasks involved in making a program respond to events by triggering functions.

Event listener

a command that can be set up to trigger a function when a particular type of event occurs on a particular UI element.

UI Elements

on-screen objects, like buttons, images, text boxes, pull down menus, screens and so on.

User Interface

controls how you enter data and instructions and how information is displayed on the screen

Debugging

Finding and fixing problems in your algorithm or program.

data type

indicates the type of data that can be stored in a field

expression

a group of symbols that make a mathematical statement

Variable

A symbol used to represent a quantity that can change

==

The equality operator (sometimes read: "equal equal") is used to compare two values, and returns a Boolean (true/false).

Global Variable

A variable that can be used in any part of the program.

if statement

The common programming structure that implements "conditional statements"

local variable

A variable that can only be accessed from a specific portion of a program

Variable Scope

dictates what portions of the code can "see" or use a variable, typically derived from where the variable was first created. (See Global v. Local)

concatenate

link together

string

A sequence of characters

conditional

an if-then statement

Selection

A generic term for a type of programming statement (usually an if-statement) that uses a Boolean condition to determine, or select, whether or not to run a certain block of statements.

Boolean

True/False

Boolean Expression

An expression that is either true or false.

iterate

loop

while loop

a programming construct used to repeat a set of commands (loop) as long as (while) a boolean condition is true

Models and Simulations

programs which replicate or mimic key features of a real world event in order to investigate its behavior without the cost, time, or danger of running an experiment in real life.

array

an orderly arrangement

list

Give a sequence of brief answers with no explanation.

key event

an event triggered by pressing or releasing a key on the keyboard.

for loop

A typical looping construct designed to make it easy to repeat a section of code using a counter variable. The for loop combines the creation of a variable, a boolean looping condition, and an update to the variable in one statement.

Return Value

The value provided as the result of a function call.

canvas

element used to draw graphics

Which of the following are true statements about digital certificates in Web browsers?

I. Digital certificates are used to verify the ownership of encrypted keys used in secured communication.

II. Digital certificates are used to verify that the connection to a Web site is fault tolerant.

(A) I only

(B) II only

(C) I and II

(D) Neither I nor II

A

Which of the following is FALSE about event-driven programs?

**A. Event-driven programs do not implement algorithms.

B. Some portions of an event-driven program may never execute while the program is running.

C. An event-driven program is written to respond to specified events by executing a block of code or function associated with the event.

D. The order in which an event-driven program will run cannot always be known ahead of time.

E. Event-driven programs can be run multiple times with different outcomes, based on user interactions.

Which of the following is FALSE about element IDs?

**A. An element with a unique ID must always have an event handler associated with it.

B. Any element that needs to be triggered by onEvent must have a unique ID.

C. Two or more onEvent calls may reference the same ID.

D. While not a requirement, IDs should be meaningful and descriptive.

E. IDs allow a programmer to reference interface elements within their code.

Consider the code segment below:

var a = 0;

var b = 3;

var c = 4;

a = a+c

b = a+c

c = a+c

What are the values of a, b, and c after this code segment has been run?

a: 4 , b: 8, c: 8

Jasmine is writing a shopping app. She has created a variable to keep track of the number of items in the shopping cart. Every time someone clicks the "addItemButton", she would like the variable to increase by 1.

var carTotal = 0;

onEvent("addItemButton", "click", function() {

//missing code

console.log(carTotal);

What code should Jasmine insert where it says in order for her app to work?

A. cart total = 1;

B. cartTotal + 1;

C. cartTotal = cartTotal +1;

D. var cartTotal = cartTotal + 1;

E. var cartTotal + 1;

C. cartTotal = cartTotal +1;

*A programmer wrote an essay for his history class, and realized he has confused the names of Benjamin Franklin and Alexander Graham Bell. Instead of going through the whole paper and changing the names, he used the following incorrect algorithm in an attempt replace every occurrence of "Benjamin Franklin" with "Alexander Graham Bell" and vise versa:

- First, change all occurrences of "Benjamin Franklin" to "apple"

- Then, change all occurrences of "apple" to "Alexander Graham Bell".

- Then, change all occurrences of "Alexander Graham Bell" to "Benjamin Franklin".

Here is an example of one of the sentences from the paper:

Alexander Graham Bell was born 141 years before Benjamin Franklin, so he was never able to telephone his neighbors.

Which of the following is the result of running the described incorrect algorithm on the sentence above?

A. Benjamin Franklin was born 141 years before Alexander Graham Bell, so he was never able to telephone his neighbors.

B. apple was born 141 years before Benjamin Franklin, so he was never able to telephone his neighbors.

C. Alexander Graham Bell was born 141 years before apple, so he was never able to telephone his neighbors.

D. Benjamin Franklin was born 141 years before Benjamin Franklin, so he was never able to telephone his neighbors.

E. Alexander Graham Bell was born 141 years before Alexander Graham Bell, so he was never able to telephone his neighbors.

E. Alexander Graham Bell was born 141 years before Alexander Graham Bell, so he was never able to telephone his neighbors.

a in binary value

01100001

A in binary value

01000001

c in binary value

01100011

D in binary value

01000100