AES-256-CBC stands for "Advanced Encryption Standard with a 256-bit key in Cipher Block Chaining (CBC) mode." It is a type of symmetric key encryption algorithm that uses a 256-bit key to encode and decode data.
AES is a widely used and well-respected encryption algorithm that is considered to be very secure. It was developed by the National Institute of Standards and Technology (NIST) and has been approved by the U.S. government for use in a variety of applications.
The "256-bit" part of the name refers to the size of the key that is used with the algorithm. A larger key size means that there are more possible key combinations, which makes it more difficult for an attacker to guess the correct key.
The "CBC" part of the name refers to the block cipher mode that is used with the algorithm. In cipher block chaining (CBC) mode, each block of plaintext is XORed with the previous ciphertext block before being encrypted. This helps to ensure that even if the plaintext contains repeated patterns, the resulting ciphertext will not contain any repeated patterns.
AES-256-CBC is often used to encrypt sensitive data, such as financial transactions and personal information, because it is considered to be very secure. It is also widely supported, so it can be used with a variety of systems and devices.