COMPSCI

Phishing

Scammers impersonate legitimate institutions to trick users into providing personal data

Malware

Malicious software that damages or controls systems

keylogger

records keystrokes to access confidential information

Rogue Access Points

Fake wireless networks designed to intercept data

Caesar Cipher

Substitution cipher shifting letters by a set number.

Letter Frequency Analysis

Muslim scholars identified patters in letter usage to decrypt ciphers

Symmetric Encryption (Private Key)

Use the same key for encryption and decryption. Vulnerable to brute force and frequency analysis

Asymmetric Encryption (public key)

Use a public key for encryption and a private key for decryption

SSL

Secure website communications

Brute Force Attack

Malicious user guess passwords through trial and error

Logic Errors

Caused by incorrectly written conditional statements

Runtime error

Incorrect user input

Design Laws

Incomplete testing or failure to anticipate user interactions

Bit

(binary digit) represents a single 1 or 0

Byte

8 bits allowing 2^8=256 combinations

ASCII

Early standard for character representation, using 7 or 8 bits. converts characters to binary or decimal and vice versa

Ladder of Abstraction

A conceptual framework that represents how different levels of abstraction are used in computing systems

Machine Code/ Binary Code

low-level instructions that the computer’s hardware understands. consists of binary digits

Assembly Language

low-level programming language that provides symbolic names.

High Level Programming Languages

Python, Java, C++, JavaScript

Internet

Computer network consisting of interconnected networks using standardizing communication protocols

Network

involves interconnected devices able to send and receive data

Servers

Provide resources and services to clients

DNS Servers

Translate domain names to IP addresses

ISPs

Provide access to the internet

Routers

Direct packs across networks

Packs

Data is broken into smaller chunks called packets to ensure efficient and reliable transmission

Transport Layer

Responsible for ensuring end-to-end data transmission

TCP (Transmission Control Protocol)

Reliable, connection-oriented protocol

UDP (User Datagram Protocol)

Faster connections protocol

Lossless

Reconstructs the original file perfectly

Lossy

Reduces file size more but sacrifices some data quality

Sequential Processing

tasks one after the other

Parallel Processing

tasks are divided into smaller chucks and executed simultaneously

Scalability

More machines can be added to handle increasing data or requests

Reliability

Fault tolerance ensures that failure of more machine does not affect the overall system

Home Distributed Comparing Projects

Volunteers contribute their idle computer processing power to large computing projects

Crowdsourcing

relies on humans, and then computers take over to combine and analyzing data.

IPOS chart

the flow of data in a computing system: how data is input, processed, output, and stored