DIRECTV uses directv descramblers to
restore intentionally scrambled video signals from satellites to
the original unscrambled form.
The directv descramblers unscramble the
video signals using the following method:
The authorization center creates the
master data stream. This data stream contains a digitally derived
key based upon the serial number of EACH authorized decoder and a
"Tier bit" for EACH channel it is authorized to receive
(determined by PAYING for the service)
"SEED KEYS" in the receiver itself combine
with the other half of the key (transmitted by the authorization
center) and create the master key used to decode the audio and
turn on the video descrambling circuit
Once the directv descramblers unscramble
the signal an access card is then used as a means of providing
certain programming to certain households, depending on what
package has been paid for. The card is known as a "Conditional
Access Module," or CAM. Each card has a unique identification
number (called the CAM ID) which is how DirecTV can add or remove
programming from each and every individual card.
For more information on directv
descramblers and the related products and services visit the
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