Gefen GTB-HD-SIGGEN - Manual (Page 39)

33
PATTERN SUMMARY
Once HDCP has been enabled, the screen will appear similar to the following:
The HDCP pattern provides a full three phase authentication:
Phase 1:
a The HD Pattern Signal Generator writes a 64-bit random number (A ((
N
) to the sink
/ receiver (Rx).
b The receiver responds by sending its own KSV (B
KSV
) to the transmitter (Tx).
V
The Receiver also sends the repeater bit, used to determine if the sink / receiver
acts as a repeater. During this step, the transmitter also verifi es that B
KSV
has
V
not been revoked and has the proper format
c If A
KSV
and
V
B
KSV
are deemed to be valid, then the receiver (sink) and transmitter
V
(source) each generate R0 (the receiver generates R
0*
. R
0*
is read by the
*
transmitter and compared with R
0
. If R
0
= R
0 0*
then the authentication phase is
*
successful. If they are not equal, HDCP authentication will fail.
Phase 2:
d As long as R0 = R0’, the transmitter will begin sending encrypted video.
Phase 3:
e Every 128 frames (2 sec), the Tx and Rx generate a value RI which is similar to
I
the R
0
values. Comparing these values between the Tx and Rx verifi es that the
link is synchronized.