A stream of content has multiple sub-streams, where each sub-stream
comprises a part of the content and is divisible into logical blocks
bounded by intrinsic partitions. For each sub-stream, a specification of
the logical blocks bounded by the intrinsic partitions is defined and the
sub-stream is divided into the logical blocks bounded by the intrinsic
partitions. Each divided logical block is encrypted and then divided into
one or more portions to produce corresponding pieces of data, and each
piece of data is placed into a data packet as a payload thereof. Each
data packet is transmitted to a recipient thereof, and the recipient can
retrieve the pieces of data from the payloads of the packets, reconstruct
the encrypted logical blocks, and manipulate the sub-stream on a
per-logical block basis without necessarily decrypting each encrypted
logical block.