Cybersecurity, Data Privacy, and Algorithms in Computer Science

PII (Personally Identifiable Information)

Any data that can help identify you, such as your address or name, directly or indirectly identify individuals.

Indirect

A phone number, has area code, phonebook could identify a person.

Data breach

Attackers can steal PII from companies.

HTTP Cookies

Small pieces of text stored by a browser to help websites remember users and personalize experiences.

How Cookies Work

Browser requests website; server sends a cookie in response; browser stores cookie; browser sends cookie with future requests; server personalizes responses.

First-party cookie

Created by the website you visit directly.

Third-party cookie

Created by outside resources/services loaded by the website.

Phishing attack

An attempt to trick a user into divulging their private information.

Spear phisher

Will research a user and send an email specifically targeting them.

Rogue Access Points

An access point installed on a network without the network owner's permission.

Passive interception

A rogue access point can read your data but cannot manipulate it.

Malware

Malicious software installed without the user realizing it.

Trojan horse

A harmful program that masquerades as a legitimate program, often downloaded onto computers by unknowing users.

Virus

Self-replicating software that contains code that copies itself into other files on the system.

Worm

Self-replicating software that copies itself into entirely different computers within the network.

Spyware

Steals data and sends it back to the malware creators.

Firewall

A system that monitors incoming and outgoing network traffic to a computer or internal network, and determines what traffic to allow.

Antivirus software

Protects an individual computer by constantly scanning files and identifying malware.

Encryption

Encoding data, scrambling the data according to a secret key.

Decryption

Decoding data, recovering the original data from scrambled data by using the secret key.

Code cracking

Uncovering the original data without knowing the secret, by using a variety of clever techniques.

Symmetric encryption

Any technique where the same key is used to both encrypt and decrypt the data, faster, less secure.

Public key encryption

An asymmetric encryption technique which uses different keys for encryption and decryption, allowing computers over the Internet to securely communicate with each other, slower, more secure.

Transport Layer Security (TLS)

Adds a layer of security on top of the TCP/IP transport protocol, relies on public key.

Digital certificate

Proves the ownership of an encryption key.

HTTPS (Hypertext Transfer Protocol Secure)

Protects the privacy of users and prevents tampering, implemented by encrypting HTTP requests and responses with the TLS protocol.

Multi-factor authentication

Requires multiple pieces of information to authenticate, requires at least 2 steps.

Cybercrime

An attacker can use PII revealed in public posts to help them steal the identity of a social media user or hack into their accounts.

Web archiving services

The Internet archive is a non-profit that attempts to make copies of all the pages on the Web.

Crowdsourcing

A way to take advantage of the large network of potential contributors online and funnel their resources into an output.

Crowdfunding

A way to raise funds for charitable causes, where the reward for donors is simply the joy of giving back.

Sensor

A low-power device that can detect some aspect of its environment and send the data to another device.

Connected sensor

A sensor that also has a way to send data to either a local network or the Internet.

Sensor network

A group of sensors where each sensor monitors data in a different location and sends that data to a central location for storage, viewing, and analysis.

Smart building

Uses technology to optimize the comfort and security of the building, while minimizing cost and environmental impact.

Algorithms

Can be created from an idea, by combining existing algorithms, or by modifying existing algorithms.

Efficiency

Can be measured by the number of times a statement or group of statements executes.

Sequential computing

Operations performed in order one at a time, takes as long as the sum of all its steps.

Parallel computing

Program into multiple smaller sequential computing operations, some performed simultaneously.

Distributed computing

Multiple devices used to run a program, much larger problems solved quicker.

Speedup of a parallel solution

Measured in the time it took to complete the task sequential divided by the time it took to complete the task parallel.

Binary Search

Data in a list must be sorted for binary search to work; max amount of times it's split in half is based on powers of 2.

Heuristic

A shortcut an algorithm uses to find a quick, approximate answer instead of checking every possible solution.

Undecidable problem

One that should give a 'yes' or 'no' answer, but yet no algorithm exists that can answer correctly on all inputs.