Technical Manual

7-1
Secure Modules
7
Introduction
The secure modules are designed to digitally encrypt and decrypt voice
and ASTRO data in ASTRO Digital XTS 3000 radios. This section covers
the following secure modules:
• NTN8253 • NTN8328
• NTN8254 • NTN8329
• NTN8255 • NTN8330
• NTN8256 • NTN8331
• NTN8257 • NTN8705
• NTN8258 • 0105956V67
• NTN8259
• NTN8260
• NTN8261
• NTN8326
• NTN8418
NOTE: The secure modules are NOT serviceable. The
information contained in this chapter is only
meant to help determine whether a problem is due
to a secure module or the radio itself.
The secure module uses a custom encryption integrated circuit (IC)
and an encryption key variable to perform its encode/decode function.
The encryption key variable is loaded into the secure module, via the
radio’s universal (side) connector, from a hand-held, key variable
loader (KVL). The encryption IC corresponds to the particular
encryption algorithm purchased. The encryption algorithms and their
corresponding kit numbers are:
DES NTN8253
DES-XL NTN8254
DES-OFB NTN8255
DVI-XL NTN8256
DVP-XL NTN8257
DES-XL and DES-OFB NTN8258
DVP-XL and DES-OFB NTN8259
DES-XL and DVP-XL NTN8260
DVP-XL and DVI-XL NTN8261
DVI-XL and DES-OFB NTN8326
DES and DES-OFB NTN8418
DVP NTN8328
DVI-XL and DVP NTN8329
DES-XL and DVP NTN8330
DVP-XL and DVP NTN8331
DES-OFB and DVP NTN8705
All, except DVP 0105956V67