AESs

AESs refer to multiple implementations and deployments of the Advanced Encryption Standard, the widely used symmetric-key block cipher. AES encrypts data in 128-bit blocks with a key length of 128, 192, or 256 bits. The algorithm was designed by Vincent Rijndael and Joan Daemen and selected by NIST as the successor to DES, becoming the AES standard in 2001. The design uses a substitution-permutation network and supports strong security with efficient software and hardware performance.

The cipher operates on a 4x4 byte state and applies rounds of substitutions, permutations, and mixing depending on key length (10 rounds for 128-bit keys, 12 for 192-bit, 14 for 256-bit). The key schedule derives round keys from the original key to drive the rounds.

AESs are typically used with various modes that provide, or combine, confidentiality and integrity. Common modes include CBC, CFB, OFB, and CTR for encryption, and authenticated encryption modes such as GCM and CCM, which add data integrity checks. The mode choice affects security guarantees and parallelism.

Security and deployment considerations for AESs include correct implementation to resist side-channel attacks, proper padding, and secure key management. AESs are widely used in protocols and standards for protecting data in transit and at rest, including email, web traffic, disk encryption, and database protection.