The Advanced Encryption Standard or AES is a symmetric block cipher chosen by the U.S. government to protect classified information. A block cipher is a method of encrypting data in blocks to produce ciphertext. A block cipher encrypts bits or the smallest unit of computational (relating to the process of mathematical calculation) in blocks. Block ciphers are most commonly used to encrypt large amounts of data into blocks.
A block cipher uses a fixed key to encrypt groups of data in order to maintain maximum security and confidentiality. When using a block cipher, each block consists of 128 bits. When a block cipher is used it encrypts the data and changes it from plaintext to ciphertext. A cipher block then creates two different algorithms, one for encryption and one for decryption.
There are advantages and disadvantages to using a block cipher. One advantage is that they go undetected and boast a strong resistance to tampering. A disadvantage is that the speed at which it is encrypted isn’t as fast as some of the other methods. This happens because the data is encrypted in blocks instead of individual pieces. Another disadvantage is that any mistake even a small symbol can jeopardize the entire block.