# CS Principles 2018

## Unit 4 - Big Data and Privacy

### Lesson 1: What is Big Data?

• Big Data: a broad term for datasets so large or complex that traditional data processing applications are inadequate.
• Moore's Law: a predication made by Gordon Moore in 1965 that computing power will double every 1.5-2 years, it has remained more or less true ever since.

### Lesson 4: Rapid Research - Data Innovations

• One-pager: A business/corporate term for a one-page document that summarizes a large issue, topic or plan.

### Lesson 7: Simple Encryption

• 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 encryption: 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 letters of the alphabet.

### Lesson 8: Encryption with Keys and Passwords

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

### Lesson 9: Public Key Cryptography

• asymmetric encryption: used in public key encryption, it is scheme in which the key to encrypt data is different from the key to decrypt.
• modulo: a mathematical operation that returns the remainder after integer division. Example: 7 MOD 4 = 3
• 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: an encryption scheme in which the key used to encrypt data is also used to decrypt (contrast with: asymmetric encryption)

### Lesson 10: Rapid Research - Cybercrime

• Antivirus Software: usually keeps big lists of known viruses and scans your computer looking for the virus programs in order to get rid of them.
• DDoS Attack: Distributed Denial of Service Attack. 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.
• Firewall: software that runs on servers (often routers) that only allows traffic through according to some set of security rules.
• Phishing Scam: a thief trying to trick you into sending them sensitive information. Typically these include emails about system updates asking you send your username and password, social security number or other things.
• 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 program that runs on a computer to do something the owner of the computer does not intend.