Abstract: A computer-implemented method of encrypting a data object of variable size utilizing an inner encryption algorithm can take a variable size input and of outputting, as its output, an encrypted version of the variable size input. The method comprises compressing or encoding the data object in its totality to obtain a compressed or encoded version of the data object in a format compatible with the inner encryption algorithm, encrypting, by the inner encryption algorithm, the compressed or encoded version of the data object to obtain an encrypted version of the data object, and decompressing or decoding the encrypted version of the data object to obtain a decompressed or decoded version of the encrypted version of the data object, which constitutes a format-preserved encrypted version of the data object.

Abstract: A database server system is provided for computer-implemented communication of electronic data between a computer-readable storage medium for storing such data and a computer-implemented application for performing at least one operation to the data. The data are structured in a first table of rows and columns defining a plurality of data cells. The database server system is configured to receive a read request from the application to return data of the data cells, and perform a format-preserving encryption or decryption operation to the data in the at least one of the data cells prior to returning the data to the application, and/or to receive a create or an update request from the application, wherein the create or update request causes a write operation to at least one of the data cells in the storage medium. A format-preserving encryption or decryption operation is performed prior to carrying out the write operation.

Abstract: In a computer-implemented method of performing Feistel-network-based block-cipher encryption of plaintext, a block cipher algorithm is implemented based on tracks and S-boxes, and plaintext is split into plaintext portions, wherein the number of plaintext portions is equal to the number of tracks, and the sum of all of the portion sizes is equal to the size of the plaintext. The block cipher is adjustable to fit the size of the plaintext, and the size of the plaintext determines the number of plaintext portions and the size of the individual plaintext portions. The size of the input for the S-box of each track of the block cipher is at least equal to the portion size of the plaintext portion fed into the S-box.

Abstract: A computer-implemented method of encrypting a data object of variable size utilizing an inner encryption algorithm can take a variable size input and of outputting, as its output, an encrypted version of the variable size input. The method comprises compressing or encoding the data object in its totality to obtain a compressed or encoded version of the data object in a format compatible with the inner encryption algorithm, encrypting, by the inner encryption algorithm, the compressed or encoded version of the data object to obtain an encrypted version of the data object, and decompressing or decoding the encrypted version of the data object to obtain a decompressed or decoded version of the encrypted version of the data object, which constitutes a format-preserved encrypted version of the data object.