According to one example, a system includes a first computing device that determines data for transmittal to a second computing device, and determines transmittal mapping data. The first computing device also breaks the data into one or more portions, and, for each of the one or more portions of the data, the first computing device replaces the respective portion of the data with a transmittal token included in the transmittal mapping data. The first computing device also transmits the transmittal tokens for receipt by the second computing device.