User's Guide

Requesting an Over-the-Air Rekey (ASTRO
Conventional Only)
Ensure that the Unique Shadow Key (USK) is loaded
into the radio with the key-variable loader (KVL)
before the rekey request can be sent. Refer to your
local key management supervisor for more
information.
This feature, also known as OTAR, allows the
dispatcher to reprogram the encryption keys in the
radio remotely. The dispatcher performs the rekey
operation upon receiving a rekey request from the
user.
1
or to Reky.
2 Press the Menu Select button directly below
Reky.
3 Perform one of the following actions:
•
Press the PTT button to send the rekey
request.
• Press the PTT button again, or the Home or
Emergency button, to exit the feature and
transmit in normal mode.
If the rekey operation fails, you hear a bad-key
tone and the display shows Rekey fail.
Note: The rekey operation failure indicates that
your radio does not contain the Unique Shadow
Key (USK).
MDC Over-the-Air Rekeying (OTAR) Page
This feature allows you to view or define MDC Over-
the-Air Rekeying (OTAR) features. It is applied only
when operating in secure encrypted mode and only
for conventional communications. In additional to
Rekey Requests, OTAR transmissions include
Delayed Acknowledgements, and Powerup
Acknowledgements.
Some of the options selected may also need to be set
up at the Key Management Controller (KMC) site to
work properly.
Note: This feature must be preprogrammed by a
qualified radio technician. Check with your dealer or
system administrator for more information.
Infinite UKEK Retention
This feature enables Unique Key Encryption Key
(UKEK) to be permanently stored in the radio even
when all of the encryption keys is erased. Without this
Advanced Features
101
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