User Manual

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letter (“D” in this example). If the radio is configured for numeric-only
passwords, do not enter # between duplicated numbers.
NOTE
If the password is wrong, the radio will not successfully
register with the network for wide area voice reception.
The radio can still be used in single-site mode.
3.11.2 DTMF Overdial
Using the DTMF microphone, the radio can transmit DTMF tones
corresponding to numbers/characters 0 — 9, * and # on the mic’s keypad. To
overdial numbers/characters, transmit by pressing and holding the PTT button
and then, press the corresponding keys (one at a time) on the keypad.
3.12 ENCRYPTION
In the OpenSky network, both data and voice use a 128-bit key encryption
standard published by the Federal Information Processing Service (FIPS),
called Advanced Encryption Standard (AES). AES is approved by the U.S.
Department of Commerce for encryption of classified materials.
When encryption is enabled on the network, data is encrypted from the MDIS
to the Mobile End System (MES) (e.g., M-803 mobile radio). This form of
encryption provides air-link security.
Voice encryption is handled either automatically or manually. Automatic
encryption is initiated through the Network Administration Server (NAS) for a
specific talk group and requires nothing from the user. Manual encryption is
initiated by two or more radio users and requires DTMF microphones. Both
methods of encryption are discussed in the following sections.
3.12.1 Automatic Encryption
For automatic encryption, a network administrator will select the talk group to
be encrypted at the interface to the NAS. Once the talk groups have been
selected and identified as secure, credentials for key generation are generated
automatically by the system and provisioned to authorized users. This process
requires that authorized users login to the network and be authenticated.
Encryption keys require no manual handling and are never sent “in the clear”
over any network interface or air-link.
1. “Pls Login” appears displayed in the bottom line of the dwell display.
2. Login normally using the DTMF microphone to enter User ID and
Password.
If a user is engaged in a call on a talk group encrypted at the network
administrator level, “Secure Call” will appear in the bottom line of the dwell
display if the user is logged in to that talk group.