AES

The standard symmetric cipher used to encrypt data with a shared secret key.

AES (Advanced Encryption Standard) is the block cipher the world settled on for fast, strong symmetric encryption. A constant-time, table-free implementation avoids data-dependent memory lookups so that timing side-channels can't leak the key — an important defense that naive table-based versions lack. The same key encrypts and decrypts, which is what 'symmetric' means.