AES

The widely used symmetric block cipher that replaced DES, available in 128, 192, and 256-bit keys.

AES is the U.S. government standard symmetric block cipher that replaced DES, operating on fixed-size blocks with key choices of 128, 192, or 256 bits. Because it is fast and hardware-accelerated on modern CPUs, it secures data at rest and in transit across TLS, VPNs, full disk encryption, and Wi-Fi. As a symmetric algorithm it uses one shared secret for both encryption and decryption, which contrasts with asymmetric systems like RSA; AES is often paired with an asymmetric exchange that safely delivers that shared key.