1. A method of transmitting a stream of content having multiple sub-streams, each sub-stream comprising a part of the content and being divisible into logical blocks bounded by intrinsic partitions, the method comprising, for each sub-stream: defining for the sub-stream a specification of the logical blocks bounded by the intrinsic partitions, wherein the intrinsic partitions are rational boundaries intrinsic to the underlying sub-stream; dividing the sub-stream into the logical blocks bounded by the intrinsic partitions; encrypting each divided logical block; dividing each encrypted logical block into one or more portions to produce corresponding pieces of data; placing each piece of data into a data packet as a payload thereof; and transmitting each data packet to a recipient thereof, whereby the recipient retrieves the pieces of data from the payloads of the packets, reconstructs the encrypted logical blocks, and manipulates the sub-stream on a per-logical block basis prior to decrypting each encrypted logical block.