Introduction

Cyber security (also written cybersecurity) is the practice of protecting computers, networks, programs, and data from digital attacks.

Think of it like locking your house:

• Your computer is your house.
• Your data (photos, passwords, bank info) are your valuables.
• Hackers are burglars trying to break in.
• Cyber security is the locks, alarms, and security cameras that protect everything.

1️⃣ What is Cyber Security?

Cyber security is the protection of:

• Computers
• Smartphones
• Networks
• Servers
• Data

from unauthorized access, damage, or theft.

It includes technologies, processes, and practices designed to protect systems from attacks.

2️⃣ Why is Cyber Security Important?

Because everything today is digital:

• Online banking
• Social media
• E-commerce
• Government systems
• Hospitals

A cyber attack can:

• Steal money
• Leak private data
• Shut down businesses
• Damage reputations

Famous example:

• The WannaCry ransomware attack in 2017 infected over 200,000 computers worldwide.

3️⃣ The CIA Triad (Core of Cyber Security)

Cyber security is based on three main principles:

1. Confidentiality

Only authorized people can access information.

Example: Password-protected email.

2. Integrity

Data cannot be altered without permission.

Example: Bank balances must not be changed by hackers.

3. Availability

Systems and data must be accessible when needed.

Example: A hospital system must always work.

These three together form the CIA Triad.

4️⃣ Types of Cyber Threats

1. Malware

Malicious software like:

• Viruses
• Worms
• Trojans
• Ransomware

Example: WannaCry

2. Phishing

Fake emails or messages that trick you into giving passwords.

Example:

You receive an email saying:

“Your bank account is locked. Click here.”

But it’s fake.

3. DDoS (Distributed Denial of Service)

Attackers flood a server with traffic to crash it.

4. Man-in-the-Middle (MITM)

An attacker secretly intercepts communication between two parties.

5️⃣ Types of Cyber Security

1. Network Security

Protects internal networks from attackers.

2. Application Security

Protects software from vulnerabilities.

3. Cloud Security

Protects data stored online (Google Drive, AWS, etc.)

4. Mobile Security

Protects smartphones and tablets.

5. Information Security

Protects data from unauthorized access.

6️⃣ Basic Security Practices (For Beginners)

Here are simple but powerful habits:

✔ Use strong passwords

✔ Use two-factor authentication (2FA)

✔ Update software regularly

✔ Avoid clicking unknown links

✔ Install antivirus software

✔ Use a firewall

7️⃣ Example: Password Hashing (Basic Code Example)

Passwords should NOT be stored as plain text.

❌ Bad way:

password = "mypassword123"

If hacked, the attacker sees the password.

✅ Better way: Store a hash instead.

Example in Python:

import hashlib

password = "mypassword123"

# Convert password into a hash
hashed_password = hashlib.sha256(password.encode()).hexdigest()

print("Original Password:", password)
print("Hashed Password:", hashed_password)

What this does:

• Converts password into a scrambled string.
• Even if stolen, it’s harder to reverse.

8️⃣ Example: Simple Password Strength Checker

import re

def check_password_strength(password):
    if (len(password) >= 8 and
        re.search("[a-z]", password) and
        re.search("[A-Z]", password) and
        re.search("[0-9]", password)):
        return "Strong Password"
    else:
        return "Weak Password"

print(check_password_strength("Test1234"))

This checks:

• At least 8 characters
• Contains lowercase
• Contains uppercase
• Contains numbers

9️⃣ What Does a Cyber Security Professional Do?

They:

• Monitor networks
• Detect attacks
• Fix vulnerabilities
• Perform ethical hacking (penetration testing)
• Secure company systems

Common roles:

• Security Analyst
• Ethical Hacker
• Security Engineer
• SOC Analyst

🔟 Career Path in Cyber Security

To start:

1. Learn networking basics
2. Learn operating systems (Windows/Linux)
3. Learn programming (Python recommended)
4. Understand ethical hacking basics
5. Study tools like:

• Wireshark
• Nmap
• Metasploit

Certifications beginners often take:

• CompTIA Security+
• CEH (Certified Ethical Hacker)

import hashlib
import re

# ---------------------------
# Password Hashing Example
# ---------------------------

password = "mypassword123"
hashed_password = hashlib.sha256(password.encode()).hexdigest()

print("Original Password:", password)
print("Hashed Password:", hashed_password)

# ---------------------------
# Password Strength Checker
# ---------------------------

def check_password_strength(password):
    if (len(password) >= 8 and
        re.search("[a-z]", password) and
        re.search("[A-Z]", password) and
        re.search("[0-9]", password)):
        return "Strong Password"
    else:
        return "Weak Password"

print(check_password_strength("Test1234"))