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8-4 
Viking Portable 600 Radio Operating Manual
Secure Communication (Encryption)
example, as shown in Figure 8.1, PID 4 selects SLN 24 which selects key slot 24 in both 
keysets. This slot contains Key ID 69 in Keyset 1 and Key ID 91 in Keyset 2. Only one 
keyset is active at a time. The actual key chosen between these two to transmit with will 
depend on which keyset is active, Keyset 1 or Keyset2.
8.2.3 Maintaining Keys in Memory
The radio may need to be connected to a constant power source to preserve the encryption 
keys in memory. The radio may be programmed to determine if keys are permanently 
stored in memory or erased soon after power is removed.
If programmed for infinite key retention, keys are stored in memory and are not lost when 
power is removed. If it is disabled, they are maintained only until the storage capacitance 
discharges. 
With Viking Portable models, storage capacitors maintain the supply voltage 
(and encryption keys) for approximately 3.5 minutes without power applied. Therefore, 
when changing the battery, make sure to reattach another within 3.5 minutes.
8.2.4 Encryption Key Select
Note
This feature is available on P25 trunking and conventional channels.
When multiple encryption keys are programmed (see preceding information), the Key 
Select option button can be programmed to allow selection of another key for the current 
channel. This feature changes the PID (hardware location) of the key, and the change is 
permanent (cycling power or selecting a different channel does not reselect the original 
key). Therefore, to switch back to the original key, it must be manually reselected. Proceed 
as follows to select a key:
Press the Key Select button or select that menu parameter.
Press the Up/Down buttons to display the desired key and then press the <F2> (Select)
 
button to select it. Press the Key Select button again to return the display to normal 
operation.
8.2.5 Encryption Key Erase
A Erase Key menu item can be programmed that allows the user to permanently erase all 
stored keys. If OTAR TEK and KEK keys are stored, all keys of both types are erased. 
This function can be used to ensure that unauthorized encrypted calls can no longer be 
placed or received by a radio.
Preliminary Draft 3/9/12