🔐 What is Encryption?

Encryption is the process of transforming readable data (plaintext) into an unreadable form (ciphertext) using algorithms and secret keys. Think of it as locking your information in a digital vault — only someone with the right key can unlock it.

Example:
Original Message: “Hello”
Encrypted Message: “Xy@#12!”
Only someone with the key can turn “Xy@#12!” back into “Hello”.

💡 Why Do We Need Encryption?

  • Privacy: Protects personal info like passwords, messages, and bank details.

  • Secure Transmission: Prevents hackers from reading data sent over the internet.

  • Data Safety: Makes stolen or hacked data useless without the decryption key.

🔄 Types of Encryption

🔐 Symmetric Encryption

[Image Placeholder: Two people sharing the same key icon]

  • Uses the same key for encryption and decryption.

  • Requires both parties to share a secret key.

✅ Popular Algorithms:

🔸 AES (Advanced Encryption Standard)

  • Block Size: 128 bits

  • Key Sizes: 128, 192, or 256 bits

  • Used in: WhatsApp, VPNs, online banking

  • Strengths: Fast, secure, and globally trusted

  • Weakness: Requires secure key sharing

🔸 DES (Data Encryption Standard)

 

  • Block Size: 64 bits

  • Key Size: 56 bits

  • Used in: Older systems

  • Weakness: Can be cracked in hours – obsolete today

🔸 3DES (Triple DES)

  • Applies DES three times

  • Key Size: 112 or 168 bits

  • Used in: Banking (historically)

  • Weakness: Slower and outdated

🔸 RC4 (Rivest Cipher 4)


  • Type: Stream Cipher

  • Key Size: 40–2048 bits

  • Strengths: Fast, easy to implement

  • Weakness: Vulnerable – no longer secure

🔸 RC5 & RC6

  • Block Sizes: 32–128 bits

  • Key Sizes: up to 2040 bits

  • Strengths: Flexible, fast

  • RC6 was a finalist in the AES competition

  • Weaknesses: Not widely adopted, less tested