Features
User Manual for AZ110 Broadcast Satellite Modulator with ASI interface
version 3.2
92
SHAPING THE FUTURE SATELLITE OF COMMUNICATIONS
8.3.3.7
Changing Group Keys
Group keys need to be changed by a trusted person or entity. The devices are set
in expert mode and the group key is changed. The security of this operation relays
on the security level of the entity modifying the group key.
For remote group key update, use a secure connection up to the
device or at least up to the machine controlling the device.
8.3.3.8
Multi-stream Transmissions to Different Groups of Receivers
If receivers are only part of one group and all receivers of the same group receive
the same content, the group key is well adapted to this case.
It can also happen that the group of receivers shall differ for each stream. But as
one receiver can receive several streams, groups must be defined per stream. In
this case two options are possible:
•
Send the (encrypted) keys of each stream only to the relevant receivers. The
sending should be unicasted as other receivers with the same group key could
decrypt the stream key too.
•
Define one group key per receiver and to send the encrypted content keys to
those receivers only. This solution has the advantage that a message
intercepted cannot be used on another receiver (unless group keys are known
publicly).
8.3.3.9
Deleting Keys
•
AZ110 >> Unit >> Control >> AES
A command “Erase All Keys” is implemented to erase all AES-related keys on that
device. This command erases (i.e. writes a 0xFFF…FF value):
•
The group key.
•
The content keys that are in use.
The content keys stored in device configurations are NOT erased.
A factory reset will erase all keys stored in the device.
