Data Length and Padding in Encryption

Cipher text are formatted in a specific way depending on which encryption properties are being used.

The block ciphers operate on blocks of data. These encryption algorithms require padding. The block size for AES is 16 bytes, and for 3DES it is 8 bytes. The input is always padded, even if it is already a multiple of the block size. Padding ensures that the input data, along with the checksum, if enabled, equals the algorithm’s block size.

Ciphertext Format

Ciphertext format uses an encryption algorithm to convert the plaintext into encrypted text. The length of an encrypted value for a non-length-preserving encryption method, such as 3DES, AES-128, or AES-256, depends on the block size and the length of the input data. The encryption properties used, including Key ID, CRC, and IV also influence the encrypted value’s length.

Examples of data length calculation by column types are provided in Examples of Column Sizes Calculation for Encryption.