1. A method for encoding and transmitting a digital file in a manner designed to facilitate authentication of a streaming transmission of the digital file, the method being performed by a system comprising a processor and a non-transitory computer-readable storage medium storing instructions that when executed by the processor, cause the processor to perform the method, the method comprising: generating a progression of check values, each check value in the progression being derived from at least one other check value in the progression and from a portion of the digital file; encrypting a final check value in the progression of check values, wherein the final check value corresponds to the beginning portion of the digital file; inserting the encrypted final check value in proximity to the beginning of the streamed transmission of the digital file; and transmitting the digital file and the progression of check values to a user's system, whereby the user's system is configured to receive parts of the digital file and to use one or more received check values to authenticate the parts of the digital file before the entire digital file is received.