Newtec MDM9000 - AES Content Protection Multi-Stream; Multi-Stream Transmissions to Different Groups of Receivers

Newtec Proprietary
Confidentiality: Unrestricted
R3.2_v1.0
305/387
Feature Descriptions
MDM9000 Satellite Modem
16.18.3.2 AES Content Protection Multi-Stream
16.18.3.2.1 Multi-Stream Transmissions to Different Groups of Receivers
Protection per stream (see section GlobalProtectionorProtectionperStreamonpage300) requires
specific attention when working with multiple receivers: a plan needs to be set up for which receivers
can receive which streams, and how these receivers are organized in groups.
If all receivers are part of the same group and all these receivers receive the same content, the keys
from one receiver can be copied to all others.
However, two other scenarios can also be implemented:
1. All receivers have the same group key, but they are only allowed to decode some of the streams.
In this case, the encrypted content keys of each of the streams can be calculated with the one
group key of all receivers. The encrypted content keys should only be sent (unicast) to the
relevant receivers, as the other receivers have the same group key and could decrypt the stream
key as well.
2. There is a different group key per receiver. In this case, an encrypted content key needs to be
generated for each relevant combination of receiver group key and clear stream key. These keys
can be multicast over the network, as only the receivers with the correct group key can decode
them.
The following tables are examples of the two possible cases.
Receivers have the same group key Receiver 1 Receiver 2 Receiver 3
group key 1 group key 1 group key 1
stream 1
clear / encrypted content key 1
encrypted key
1
stream 2
clear / encrypted content key 2
encrypted
key 2
encrypted key
2
stream 3
clear / encrypted content key 3
encrypted key
3
stream 4
clear / encrypted content key 4
encrypted key
4