What is AES encryption?
D5 · Crypto · CompTIA Security+ SY0-701AES (Advanced Encryption Standard) is a symmetric block cipher adopted by NIST in 2001 as the replacement for DES. It is the most widely used encryption algorithm in the world.
Key sizes: AES-128, AES-192, AES-256 (256-bit is strongest).
Block size: always 128 bits.
Modes of operation: ECB (avoid — insecure), CBC (needs IV), GCM (provides authentication too — preferred), CTR.
Key sizes: AES-128, AES-192, AES-256 (256-bit is strongest).
Block size: always 128 bits.
Modes of operation: ECB (avoid — insecure), CBC (needs IV), GCM (provides authentication too — preferred), CTR.
AES-256 in GCM mode is the gold standard. GCM provides both confidentiality AND integrity (AEAD — Authenticated Encryption with Associated Data). For disk encryption: AES-256 with CBC or XTS mode.