🛡️ 1. CIA Triad – The Core Security Goals
Every cybersecurity principle revolves around the CIA Triad:
Confidentiality – Keep data secret from unauthorized users.
Example: Encrypting files so only authorized users can read them.
Integrity – Ensure data is accurate and not tampered with.
Example: Using checksums, hashing, or digital signatures to verify authenticity.
Availability – Keep systems and data accessible when needed.
Example: Using backups and redundancy to prevent downtime during failures.
🌐 2. Types of Threats
You must know what you’re protecting against:
Malware – Viruses, worms, ransomware, trojans.
Phishing & Social Engineering – Trick users into revealing information.
DDoS Attacks – Overload systems to take them offline.
Insider Threats – Employees or contractors misusing access.
Zero-Day Exploits – Attacks on vulnerabilities before patches exist.
🔑 3. Authentication & Authorization
Authentication – Verifying who you are (passwords, biometrics, MFA).
Authorization – Deciding what you can access (permissions, roles).
Least Privilege Principle – Give users the minimum access they need.
🔒 4. Encryption & Cryptography
Cryptography is essential for protecting data:
Symmetric Encryption – One key for encrypt & decrypt (fast, used for bulk data).
Asymmetric Encryption – Public/private key pair (used in SSL/TLS, digital signatures).
Hashing – One-way function to verify data integrity (e.g., SHA-256).
🖧 5. Network Security Basics
Firewalls – Control what traffic enters/leaves a network.
IDS/IPS – Intrusion Detection/Prevention Systems to monitor & block attacks.
VPNs – Encrypt traffic for secure communication.
Segmentation – Separate critical systems from general network access.
🏛️ 6. Security Policies & Compliance
Policies – Rules for secure behavior (password policy, access control policy).
Compliance Standards – GDPR, HIPAA, PCI-DSS, ISO 27001 — set legal/industry requirements.
🧪 7. Risk Management
Vulnerability – Weakness that can be exploited.
Threat – Actor/event that may exploit a vulnerability.
Risk – The potential impact of a threat exploiting a vulnerability.
Mitigation – Measures to lower risk (patching, training, controls).
🛠️ 8. Incident Response & Recovery
Detection – Identify suspicious activity quickly.
Containment – Stop the attack from spreading.
Eradication – Remove malicious code or intruder.
Recovery – Restore systems & operations.
Lessons Learned – Improve defenses to prevent future incidents.