Patent ID: 8078867

Claim:
A method of authenticating data streamed as indexed data packets to a device, in which authentication data is not distributed over the packets, the method comprising: receiving, at the device, data in a streamed plurality of packets transmitted by a data server; detecting an interruption in transmission of the streamed plurality of packets from the data server, wherein the streamed plurality of packets comprises a truncated packet; determining, at the device, a packet preceding the truncated packet within the streamed plurality of packets, and identifying the packet preceding the truncated packet as a last non-truncated packet; after detecting the interruption in the streamed plurality of packets, submitting a request for a server-computed authentication value to a network-connected data authentication server with an identification of the last non-truncated packet that precedes the truncated packet as determined at the device, the data authentication server connected to the device by a network, the server-computed authentication value based on a subset of the data transmitted by the data server that comprises the last non-truncated packet but does not include the truncated packet, and the network-connected data authentication server having access to the data that was transmitted from the data server to the device; receiving the server-computed authentication value from the data authentication server, computed in response to the request; and comparing a device-computed authentication value based on a subset of the data received at the device corresponding to the subset of the data transmitted by the data server with the server-computed authentication value in order to determine if the subset of the data received at the device is authentic.