FILE: materi-05.module

Cryptography Fundamentals

Symmetric vs asymmetric. Hashing. Public key infrastructure (PKI). Cara matematis lindungi data.

RUNTIME: 28m LEVEL: intermediate STATUS: ACTIVE
ENCRYPT DECRYPT PUBLIC KEY PRIVATE KEY CRYPTOGRAPHY

1. Apa Itu Cryptography

Ilmu mengamankan komunikasi dari pihak ketiga. Sudah ada sejak Yunani kuno (Caesar cipher). Modern: matematis kompleks. Tujuan: confidentiality, integrity, authentication.

2. Symmetric Encryption

Kunci sama untuk encrypt dan decrypt. Cepat tapi sulit distribusi key. Algoritma: AES (standar), 3DES (legacy). Use case: enkripsi file, database, harddisk full disk encryption.

3. Asymmetric Encryption

Pasangan kunci: public dan private. Encrypt dengan public, decrypt dengan private. Slower tapi solve key distribution. Algoritma: RSA, ECC. Use case: SSL/TLS, signing, key exchange.

4. Hash Function

One-way function. Output fixed length. Sama input = sama output. Sedikit ubah input = output beda total (avalanche effect). Algoritma: SHA-256, SHA-3. Use case: password storage (dengan salt), integrity check.

5. PKI dan Certificate

Public Key Infrastructure. Certificate Authority (CA) verifikasi identitas dan tanda tangan public key. Browser percaya CA root. Saat akses HTTPS, browser cek certificate. Pondasi internet aman.

Practical Mission

  1. Coba enkripsi file dengan GPG
  2. Hash password sendiri dengan SHA-256 online
  3. Inspect SSL certificate situs favoritmu
  4. Pelajari sejarah Enigma machine
  5. Tulis cara HTTPS bekerja step-by-step

Recap Module