Core Cryptographic Concepts
|
Concept |
How It Works |
Real-World Use |
|
Symmetric |
Same key encrypts & decrypts (AES, DES) |
File encryption, VPN tunnels |
|
Asymmetric |
Public key encrypts, private key decrypts (RSA) |
HTTPS, email signing, SSH |
|
Hashing |
One-way transformation (MD5, SHA256) |
Password storage, file integrity |
|
Digital Sig |
Proves authenticity using private key |
Code signing, document verification |
|
SSL/TLS |
Encrypts communication over internet |
HTTPS websites, secure APIs |
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|
📌 Placement Tip: Be able to explain the difference between encoding, encryption, and hashing. Encoding (Base64) is reversible without a key. Encryption requires a key. Hashing is one-way and irreversible. |
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Common Attack Against Cryptography
- Brute Force Attack — Trying all possible keys or passwords
- Dictionary Attack — Using a wordlist to crack password hashes
- Rainbow Table Attack — Pre-computed hash table for fast cracking
- Man-in-the-Middle — Intercepting communication to decrypt/re-encrypt