A system and method for performing reliable unidirectional communication in a data network is disclosed. Unidirectional data is sent from a transmitting device to a receiving device. Prior to transmission, the data is divided into a window (401b) comprised of data bytes. A checksum value (407) is computed across data bytes comprising window (401b). Checksum value (407) is placed into an XML integrity element (404) that encapsulates window (401b) in a manner allowing a receiving device to use the contents of integrity element (404) to validate the received window (401b). Checksum value (407) is compared to a second check sum value computed across window (401b) at the receiving device. If checksum value (407) matches the second checksum value, window (401b) is validated.