What type of cipher is AES categorized as?

AES, or Advanced Encryption Standard, is categorized as a symmetric-key block cipher. This means that it utilizes the same key for both encryption and decryption, which is a characteristic of symmetric encryption methods. The block cipher aspect indicates that it processes data in fixed-size blocks, specifically 128-bit blocks in the case of AES, regardless of the amount of data being encrypted.

The reason symmetric-key algorithms like AES are widely used in practice is due to their efficiency and speed, making them suitable for encrypting large amounts of data. In contrast, asymmetric-key ciphers use different keys for encryption and decryption, which introduces more computational overhead.

AES operates with key lengths of 128, 192, or 256 bits, providing different levels of security that can be leveraged depending on the application. This high level of security, along with its efficiency, has led to its adoption as a standard for encrypting sensitive data in various applications, ranging from government communications to financial transactions and beyond.