What is AES?

AES (Advanced Encryption Standard) is a symmetric block cipher adopted as a U.S. federal standard in 2001. It supports key sizes of 128, 192, and 256 bits and operates on 128-bit blocks. AES is based on the Rijndael algorithm and is used worldwide for encrypting sensitive data—from TLS and disk encryption to file and message encryption. AES is considered secure against all known practical attacks when used with proper key management and modes of operation (e.g., AES-GCM, AES-CBC with IV).