✅ You Know When to Encrypt & When to Hash

Master the two pillars of cryptography and their blockchain applications

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Real-World Applications

🎓 Key Takeaways

Let's review the essential concepts you've learned about encryption and hashing!

🔐

Encryption

  • Reversible: Can decrypt with the right key
  • Requires Keys: Symmetric (1 key) or Asymmetric (2 keys)
  • Purpose: Confidentiality and privacy
  • Use When: You need original data back
  • Examples: HTTPS, messaging, wallets
👆

Hashing

  • One-Way: Cannot reverse to get original
  • No Keys Needed: Same input always = same hash
  • Purpose: Data integrity and unique IDs
  • Use When: Verify data hasn't changed
  • Examples: Block linking, TX IDs, passwords
🔗

In Blockchain: Both Work Together

🔐 Encryption Uses:
  • • Wallet private keys (AES-256)
  • • Transaction signatures (ECDSA)
  • • Proving ownership
👆 Hashing Uses:
  • • Linking blocks (previous hash)
  • • Transaction IDs (SHA-256)
  • • Mining (Proof of Work)
  • • Merkle trees

🧠 Critical Properties to Remember

Avalanche Effect

Change 1 bit in input → ~50% of hash bits flip

🎯
Collision Resistance

Computationally impossible to find two inputs with same hash

🔑
Key Management

Encryption security depends on keeping keys secret

🎯

Test Your Knowledge!

Ready to put your understanding to the test? Take this 5-question quiz to see how well you've mastered encryption vs hashing!