A method and device for off-loading from an application program the calculation of a data-integrity-checking value for specified data in a computer system. The data may be included in a message together with the integrity-checking value or may be in a portion of a memory window for direct memory access. The method includes communicating a selected data-integrity-checking scheme from a specified set of schemes to another processor to off-load calculation of the data-integrity-checking value. A related method associates a message to be received with a data-integrity-checking scheme, so that a receiving processor can calculate the data-integrity-checking value and transmit both the value and the message to another processor.