Figure 3-9. Traffic Encryption Key Negotiation - Comtech EF Data DMD-2050E Installation And Operation Manual

DMD2050E Universal Satellite Modem
FIPs initiated mailbox message to
MnC, MnC tells embedded channel to
set up framing for key roll. Key roll is
negotiated in the encrypted channel
and is a real time signal when new
TEK arrives in frame
Event: Rekey Timer Expired
Action: Send KA Message
MN-DMD2050E Revision 2
Event: Timer
Expired
Action: Return to
Idle
Event: Embedded Channel Active
Action: Send Key Agreement (KA) Message
Event: Key Agreement Response message received
Action: Compute TEK, Load TEK, Start Rollover
Event: Transmit Key Rollover
Action: None

Figure 3-9. Traffic Encryption Key Negotiation

TX OFF
Need to make timers configurable
Idle
MnC initiated Mailbox message to
Event: TX ON
FIPs
Action: None
Waiting for
Embedded
Channel
Waiting for
Key
Event: Timeout
Agreement Action: Resend KA Message
Response
Waiting for
Key
Rollover
Encrypting
Theory of Operation
FIPs initiated mailbox message to
MnC, MnC responds back once
embedded channel is up or timeout
occurs.
Event: Timeout
Action: None
Event: RX Sync Lost Message received
Action: Zeroize TEK
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