User's Manual

GENERAL OPERATION
16
Revised August 2002
Part No. 001-5300-007CD-NR
3.18 SECURE COMMUNICATION
3.18.1 INTRODUCTION
This transceiver may be equipped to provide
secure communication on some or all channels. This
feature encrypts the voice so that it can be understood
only by someone using a transceiver equipped with a
similar encryption device and encryption codes.
When a secure call is received or transmitted,
is indicated in the display. If equipped with the
Clear/Secure option switch and the current channel is
programmed to allow switch selection, secure commu-
nication can be manually enabled and disabled by that
switch. Otherwise, channels are strapped to Clear or
Coded operation. Secure communication can be
programmed on a per channel basis to operate in
various ways. Refer to the following for more infor-
mation:
3.18.2 CONVENTIONAL CHANNELS
On conventional analog channels, the protocol
that can be used to provide secure communication is
SecureNet™ DES or DES-XL encryption.
On conventional digital (Project 25) channels, the
SecureNet DES-OFB protocol is used. In the receive
mode, clear and secure messages are always automati-
cally detected.
3.18.3 SMARTNET/SMARTZONE AND P25
TRUNKED CHANNELS
On SMARTNET/SmartZone analog channels,
SecureNet DES or DES-XL protocol can be selected.
On SMARTNET/SmartZone and P25 Trunked digital
channels, only the DES-OFB protocol is available.
Talk groups can be strapped to Clear, Coded, or
Switch selectable, and clear and secure messages are
always autodetected.
The following calls require their own encryption
key selection: emergency, failsoft, patch, telephone,
private, and system-wide.
3.18.4 SECURENET
SecureNet is a proprietary Motorola protocol that
digitizes the voice and then encrypts it using the DES
or DVP algorithm. The SecureNet protocols include
the following:
• DVP (Digital Voice Privacy) is an earlier encryption
method that is self synchronizing using cipher feed-
back. It was originally designed to be used by
anyone needing protection from unauthorized
eavesdropping.
• DES (Data Encryption Standard) provides the
highest level of security, and also uses cipher feed-
back. It was originally designed to be used only by
the Federal government.
• DVP-XL/DES-XL - A disadvantage of the DVP and
DES encryption types is reduced communication
range when compared to clear voice. The DES-XL
and DVP-XL methods were designed to provide
better range but at the cost of lower voice quality.
They use a different type of feedback called counter
addressing.
• DES-OFB - A form of DES encryption for digital
channels that uses output feedback. This protocol
does not result in the degraded range that occurs
with analog channels.
The transmission mode (DES/DES-XL) is
selected by the programming software for each
SecureNet analog channel. If a channel is programmed
for DES-XL, it will also receive DES, but transmis-
sions always occur in DES-XL.
3.18.5 HARDWARE (ENCRYPTION) KEYS
General
NOTE: A constant power supply must be connected to
the transceiver to maintain the encryption keys in
memory. Therefore, if equipped with these keys, do not
remove the radio from battery power or disconnect the
battery for extended periods (typically 8 hours or
more).
Each SecureNet channel is assigned a hardware
key from 0-15. This is the hardware location of the
encryption key to be used. The keys in these locations
are loaded into the radio using the Motorola or PC key
loader. The keyloader converts an input of approxi-
mately 20 characters into the “key” that is loaded into