Encryption scheme for streamed multimedia content protected by rights management system

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;
• 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 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.