E F Johnson Company 2425372 Benutzerhandbuch
Draft
-4 5300 ES Series Mobile Radio Operating Manual
December 2006
11.2.1 Key and Algorithm IDs
Each encryption key is programmed with a Key ID (also called Logical ID). This ID plus
the algorithm ID (ALGID) is transmitted in the message. The radio receiving the message
must have a key programmed with the same IDs in order to decrypt it.
the algorithm ID (ALGID) is transmitted in the message. The radio receiving the message
must have a key programmed with the same IDs in order to decrypt it.
11.2.2 PID/SLN Key Management Modes
Note
The term “SLN” from the Project 25 specification is equivalent to “CKR” (Common Key
Reference) also used to define this parameter.
Reference) also used to define this parameter.
The channels, talk groups, and other calls that use encryption are linked to a specific
Physical ID (PID) when the radio is programmed using the PC Configure programming
software. For example, Zone 1, channel 1 could be programmed to select the key in PID 1
and Zone 1, channel 2 could select the key in PID 3. The PID ranges are 0-15 when the
PID mode is selected, and 1-16 when the SLN mode is selected (see Figure 11.1).
Physical ID (PID) when the radio is programmed using the PC Configure programming
software. For example, Zone 1, channel 1 could be programmed to select the key in PID 1
and Zone 1, channel 2 could select the key in PID 3. The PID ranges are 0-15 when the
PID mode is selected, and 1-16 when the SLN mode is selected (see Figure 11.1).
PID or SLN key management modes can be programmed on the Global programming
screen. More information on these modes follows.
screen. More information on these modes follows.
PID Mode - The PID mode can be used only when keys are loaded using the Motorola
KVL 3000 keyloader. When this mode is selected, keys are loaded directly into a PID
of 0-15 that corresponds to the PID programmed for each channel (if applicable). A
Keys Table is not programmed with this mode.
KVL 3000 keyloader. When this mode is selected, keys are loaded directly into a PID
of 0-15 that corresponds to the PID programmed for each channel (if applicable). A
Keys Table is not programmed with this mode.
SLN Mode - The SLN mode must be selected is either OTAR (Over-The-Air-
Rekeying) or the EFJohnson System Management Assistant (PDA keyloader) is used. It
can also be used if OTAR is not used. With this mode, keys are loaded into a SLN
(Storage Location Number), typically from 0-4095. A Keys Table must then be
programmed to link channel PIDs to a specific SLN.
Rekeying) or the EFJohnson System Management Assistant (PDA keyloader) is used. It
can also be used if OTAR is not used. With this mode, keys are loaded into a SLN
(Storage Location Number), typically from 0-4095. A Keys Table must then be
programmed to link channel PIDs to a specific SLN.
The use of this type of indirect linking allows keysets and key IDs to be changed via
OTAR while keeping the mapping from the channel or talk group the same. For
example, as shown in Figure 11.1, 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.
OTAR while keeping the mapping from the channel or talk group the same. For
example, as shown in Figure 11.1, 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.
11.2.3 Maintaining Keys in Memory
The radio may need to be connected to a constant power source to preserve the encryption
keys in memory. The programming of the Infinite Key Retention parameter determines if
keys are permanently stored in memory or erased soon after power is removed.
keys in memory. The programming of the Infinite Key Retention parameter determines if
keys are permanently stored in memory or erased soon after power is removed.
When Infinite Key Retention is enabled, 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.
power is removed. If it is disabled, they are maintained only until the storage capacitance
discharges.