The idea for Audio Secret was born as a solution designed from Advanced Video
Technologies to solve a Eurosport needs.
Eurosport is broadcasting their programs with a live commentaries in: Czeck,
Danish, Dutch,English, French, Finnish, German, Hungarian, Italian, Polish,
Portuguese, Russian, Spanish and Swedish.
The need of Eurosport is to broadcast their programs into different regions
with different languages and with different condition of access depending
from the language.
Their transmission is in clear for video and some commentaries as English,
Spanish, German, Italian and must be encrypted for some other commentaries
as Dutch, Hungarian, Polish and Russian.
To obtain this diversity of transmission using only two transponders, one
on Astra and a second on Hot Bird, maintaining the compatibility for all viewers
is to use a multi carrier transmission system with conditional access.
The audio only encryption is the solution for the multilingual network that
would like to control the single language to be distributed only to the authorised
users.
Since now, when a satellite broadcaster wants to buy a crypto transmission,he
has a lot of choices of video encryption systems, but there was no choices
for the audio only encryption.
Advanced Video Technologies has developed a special crypto for audio-only
with conditional access and with digital quality: - Audio Secret -
The first Audio Secret was installed for the Russian and the Polish languages
over the Hot Bird satellite and was installed too on the Astra satellite for
the Dutch and the Hungarian languages.
Soon new services will be launched , for more languages always within the
Eurosport network transmissions system.
Advanced Video Technologies and Eurosport agreed to propose the Audio Secret technology to other broadcasters having
same problems.
Technical specifications
The Audio secret is a system designed to broadcast encrypted bilingual or
stereo audio, with data management information, using a Musicam carrier.
The Audio Secret system is based on a MPEG modulator with
two audio channels and a crypto modulator with a centralised key management
and data control, able to handle in real time up to 230.000.000 subscribers
for both the audio channels.
The output of the modulator/cripto is directly compatible with the specifications
required from the modulators of the Musicam carrier.
The Audio Secret system does not require any modification
to the standard transmitter and it is not necessary to change satellite
transponder to expand the capacity of audio channels broadcasted simultaneously
on the same transponder.
The band pass of the entire system is within 20 Hz and 20 Khz +1
dB -1 dB
The receiver could be any standard ADR receiver with the integration of the
Audio Secret custom chip for the decryption of the
digital transmission.
Each single receiver is addressed and enabled from the SMS (Subscriber Management
System) in few seconds without the need of any extra device (card or password).
The operation of the Audio Secret custom chip is fully transparent
for other transmissions done with the Musicam carrier.
The computer used for crypting includes the SMS (Subscriber Management System)
designed to handle up 230.000.000 of users with the capability to enable or
disable a single user within few seconds.
The control of the SMS is actuated from a remote computer ( SMS Control Unit)
where the database of the subscribers is generated and where all the billing
informations are created.
The SMS can be remotely controlled from the SMS-CU even from another country!
All the system is economical and it is suitable for any kind of transmission
already existing.
The Audio Secret is recommended for crypting any audio
signal (as the one broadcasted from the radio transmission using spare bandwidth
of satellite transponder).
The same technology can be used to process any the new digital broadcasting
signal.
As a logical evolution of the Audio Secret , the AVT has developed
the Data Secret.
Data Secret is a crypto
system for data with bandwidth depending by the carrier which data are broadcasted
with.
The carriers available for the Data Secret begin from the 192 Kb/s
of the Musicam subcarrier up to the 8 Mb/s needed for the MPEG 2 video transmission.
Data Secret is capable to
address from one up to all receivers available (with a maximum of 1.000.000.000)
in a fraction of a second and can enable them for the reception of the data
addressed only to the right users.
There is no way to detect the Data Secret broadcasted information
due to continous random changes of the encryption key.
Data Secret is suitable
for all the digital communications where is required the maximum security
of informations, delivered only to the authorized users.
The identity of the users is unique and is related only to a single Data Secret chip. The chip itself can be installed
in any kind of digital receiver for data or digital video.
Any other user will never be able to receive any data due to the encryption
algorithm.
This technology will add security to DBS transmissions and, mainly, flexibility
on enabling and disabling the single customer in seconds.