How to Learn Cybersecurity Basics for CEH Certification?

Introduction

CEH syllabus assumes you already understand the theoretical foundation of cybersecurity — the OSI and TCP/IP models, how encryption actually works, difference between confidentiality and integrity, why subnetting exists, how operating systems handle processes and permissions, and the evolving threat landscape. Without this theory, even simple practical labs become confusing. At Ethical Hacking Training Institute we have seen thousands of students from non-IT backgrounds clear CEH with 90%+ marks because we spend first 30 days building crystal-clear theoretical understanding before touching any tool.

The OSI Model – Theoretical Foundation of All Network Attacks

TCP/IP Stack – How Data Actually Travels Across Networks

The TCP/IP model is the practical implementation of OSI. Application layer protocols (HTTP port 80, HTTPS 443, SSH 22) sit on top of Transport layer (TCP for reliable delivery, UDP for speed). Network layer handles IP addressing and routing. Link layer deals with MAC addresses and Ethernet frames. Understanding three-way handshake (SYN → SYN-ACK → ACK), sequence numbers, and flags (SYN, ACK, FIN, RST) is crucial because 80% of network attacks target these mechanisms. We explain every packet field with live Wireshark captures.

Master TCP/IP theory first.

Cryptography Theory – The Mathematics Behind Security

• Symmetric encryption → same key (AES-256 is current standard)
• Asymmetric encryption → public/private key pair (RSA 2048-bit)
• Hash functions → one-way, collision-resistant (SHA-256)
• Digital signatures → prove authenticity + integrity
• Diffie-Hellman → secure key exchange over insecure channel
• Perfect Forward Secrecy → session keys never stored

The CIA Triad and Beyond – Core Security Principles

Confidentiality ensures only authorized parties read data (achieved via encryption). Integrity guarantees data is not tampered (hashing + digital signatures). Availability means systems are accessible when needed (DoS protection). The Parkerian Hexad extends this with Authenticity, Possession, and Utility. Risk = Threat × Vulnerability × Impact is the fundamental equation every security professional uses for prioritization. We teach these concepts with real breach case studies (Equifax, SolarWinds, Log4j).

Operating System Theory – How Linux & Windows Really Work

• Kernel vs User mode separation
• Process vs Thread vs Service
• File permissions (chmod octal, owner/group/world)
• Windows registry vs Linux /etc configuration
• System calls and privilege rings
• Memory management and virtual memory

Understand OS theory deeply.

Threat Landscape 2025 – What Attackers Actually Target

Ransomware-as-a-Service, supply-chain attacks (SolarWinds), zero-day exploits sold on dark web, state-sponsored APT groups, and AI-powered phishing are dominating 2025. Understanding attacker TTPs (Tactics, Techniques, Procedures) from MITRE ATT&CK framework is now part of CEH theory. We cover latest ransomware families, living-off-the-land techniques, and real incident reports.

Conclusion

Strong theoretical foundation makes practical labs 10× easier. Join Ethical Hacking Training Institute’s “30-Day Foundation + CEH Combo” and get:

• Complete theory with real-world examples
• Daily quizzes & mind maps
• Personal cloud lab from day 1
• Weekend & weekday batches
• 100% placement support

Book free counselling — start building your foundation this week!

Avoid beginner mistakes.

Frequently Asked Questions

Is theory important for CEH?

Yes — 60% questions are theoretical.

How much theory in CEH?

40–50% of total syllabus is pure theory.

Can I skip theory and only do labs?

No — you’ll fail theory exam.

Is OSI model heavily tested?

Yes — 10–15 questions guaranteed.

Do you teach cryptography mathematics?

Yes — but only CEH level (no complex math).

Is threat intelligence in syllabus?

Yes — new in v13.

Which book for theory?

Official EC-Council books + our institute notes.

Is subnetting calculation needed?

Yes — we teach calculator-free method.

Do freshers understand theory?

Yes — we explain with daily life examples.

Weekend batch covers theory?

Yes — complete coverage every Saturday-Sunday.

Is CIA triad enough?

Yes for CEH, but we teach Parkerian hexad too.

Do you provide theory PDFs?

Yes — 300+ page theory + diagrams.

Is theory taught before labs?

Yes — first 15 days pure theory.

How to start theory today?

Book free foundation class — start this weekend!

Is theory boring?

Not in our classes — real breach stories make it exciting!