User's Manual

Internal Encoding
RFI-148 & RFI-900 High Output Power Paging Transmitters User Manual Page 44 of 134
4. In the “Key Generator” table, enter an arbitrary capcode for which a key will be generated (ATS226).
After a brief (~1 sec) pause, the upper and lower halves of the cryptographically secure generated encryption
key will be available in ASCII-HEX format (i.e. 32 characters for each half) for copying from the table
(ATS227 and ATS228).
SHARED KEY SETUP
The key-sharing procedure for each is defined here; refer to Table 11 to determine which approach to adopt.
KEY GENERATOR
It is recommended to use the key-generator feature whenever possible. No keys need to be entered or managed
by the user; matching cryptographically secure keys are either generated in both devices at run-time, where a
STIEN decryption-capable device is in use, or the non-STIEN decrypting device is deployed with keys as
generated by the RFI-148’s key generator:
1. Enable the encryption feature (ATS220=1).
2. Enable the key generator (ATS222=1)
3. Perform the above steps on the STIEN decryption-capable device also, if in use, or, if not:
a. Enter the customer-specific password (ATS225) that will have been provided to you on
purchase of the unit. This will “unlock” access to the encryption key entry fields.
b. In the “Key Generator” table, enter the capcode for which the key will be generated (ATS226).
c. After a brief (~1 sec) pause, the upper and lower halves of the cryptographically secure
generated encryption key will be available in ASCII-HEX format (i.e. 32 characters for each
half) for copying from the table (ATS227 and ATS228, respectively).
d. Enter this key into the encryption device.
e. Repeat steps b through d for each capcode.
SINGLE USER(-ENTERED) KEY
A user can specify their own encryption key by disabling the key generator, then entering this key into the
appropriate fields. In this scenario, all messages that meet the filtering criteria will be encrypted using this
same key, regardless of message capcode destination. This implementation is discouraged, since compromise
of this key compromises the entire system.
1. Enable the encryption feature (ATS220=1).
2. Disable the key generator (ATS222=0)
3. Enter the customer-specific password (ATS225) that will have been provided to you on purchase of the
unit. This will “unlock” access to the encryption key entry fields.