Cybersecurity Fundamentals

Encryption

Converting data into coded form to prevent unauthorized access; reversible with a key

Symmetric Encryption

Same key for encryption and decryption (e.g., AES); fast but requires secure key exchange

Asymmetric Encryption

Public key encrypts, private key decrypts (e.g., RSA); enables secure key exchange

Hashing

One-way function producing fixed-size output from any input; SHA-256, bcrypt; not reversible

Phishing

Social engineering attack using fraudulent emails/sites to steal credentials or data

Malware

Malicious software: viruses, worms, trojans, ransomware, spyware

Ransomware

Malware that encrypts victim's files and demands payment for decryption key

Firewall

Network security system that monitors and filters traffic based on security rules

Two-Factor Authentication (2FA)

Requires two different forms of verification: something you know, have, or are

SQL Injection

Attack inserting malicious SQL into input fields to manipulate databases