AP Comp Sci Principles Unit 4

Big Data

a broad term for data sets so large or complex that traditional data processing applications are inadequate

Moore's Law

a prediction made by Gordon Moore in 1965 that computing power would double every 1.5-2 years, it has remained more or less true ever since

Caesar Cipher

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

cipher

the generic term for a technique (or algorithm) that performs encryption

cracking encryptor

when you attempt to decode a secret message without knowing all the specifics of the cipher, you are trying to 'crack the encryption

decryption

a process that reverses encryption, taking a secret message and reproducing the original plain text

encryption

a process of encoding messages to keep them secret so only authorized parties can read it

random substitution cipher

an encryption technique that maps each letter of the alphabet to a randomly chosen other letter of the alphabet

vigenere cipher

a method of encrypting text by applying a series of casear ciphers based on the letters of a keyword

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

used in public key encryption, it is a scheme in which the key to encrypt data is different from the key to decrypt

modolo

a mathematical operation that returns the remainder after integer division

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 pri

SSL/TLS

an encryption layer of HTTP. When you see the little lock icon and "HTTPS" it means you are visiting a website over HTTP but the data going back and forth between you and the server is encrypted

DDoS

typically a virus installed on many computers (thousands) activate at the same time and flood a target with traffic to the point the server becomes overwhelmed-doing this can render web services like DNS, or routers, or certain websites useless or unrespo

phishing

typically a thief trying to trick you into sending them sensitive information. Typically these include emails about system updates asking you to send your username and password, SSN or other things

virus

a program that runs on a computer to do something the owner does not intend. Viruses can be used as a BotNet to trigger a DDos-style attack, or they can spy on your computer activity

two-factor authentication

adds extra security by requiring more than just your password (often a security code sent to your phone)

What is the difference about Big Data compared to data we have learned in the past and what is an example of it?

-traditional processing applications are inadequate
-there are more challenges with how to analyze and store this data

explain one data innovation and how it directly uses, produces, or consumes data

google's self driving car collects information on where you are traveling, your speed, and distance from other cars

what is meant by the title "The Cost of Free" in lesson 4?

we often trade our personal data in order to get services for free, this is part of the business model for many apps/websites

why is the vingenere cipher harder to crack than a random substitution cipher

vingere is strong because looking at the cipher text there are no discernible patterns assuming a good key was chosen. We essentially have to guess the key. Even if we know the length of the key, it is still difficult.

why is modulo used in public key cryptography

PKC is asymmetric. one key can only be used to encrypt data, and a different (but related_ key can only be used to decrypt. That "related key" relies on mathematical properties that make it easy to produce the public/private key pair, but hard to figure o

what is 37 mod 10?

7

what is 14 mod 7?

0