Abstract: The present invention provides a simple encryption method and system for encrypting data into a plurality of control and encrypted data blocks. The data to be encrypted is divided into data segments which can be of varying length. Each control block comprises the information necessary to decrypt the data contained in the encrypted data block, such as the encryption function and associated key used to encrypt a data segment, the start position of an encrypted data segment within the encrypted data block and the length of the encrypted data block. Both the control block and the encrypted data block are padded with random numbers and the start position of the encrypted data with the encrypted data block can vary.