E.F. Johnson Company 53SL ES Series, Руководство по эксплуатации

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8-2 53SL ES Series Mobile Radio Operating Manual April 2009
Encryption Keys Section 8 - Secure Communication (Encryption)
8.1.2 AES (Advanced Encryption Standard)
The 53SL ES Series radios do not support AES encryption.
8.1.3 Encryption Available With Various Channel Types
Analog Channels - On analog conventional and SMARTNET/SmartZone channels, DES
encryption provides secure communication.
Digital Channels - On digital Project 25 and SMARTNET/Smart Zone channels, the
DES-OFB protocol is used.
8.1.4 FIPS and Non-FIPS Modes
FIPS 140-2 is a Federal Information Processing Standard for encrypted radios used by the
Federal Government. This standard specifies Federal security requirements for
cryptographic modules for a wide range of applications and environments. All 53SL ES
models are FIPS certified.
8.2 Encryption Keys
An encryption key is a cryptographic variable that is required by the encryption algorithm
to encrypt and decrypt voice or data. To maintain system security, these keys must be
protected from disclosure and also periodically replaced or updated.
With the DES encryption used by EFJohnson Technologies radios (see Section 8.1), the
same encryption key is used by both the encrypting (sending) and decrypting (receiving)
radio. DES keys are generated from a string of 16 hexadecimal characters. Another four
hexadecimal characters are used to specify the key ID. Multiple keys can be loaded into a
radio using OTAR or manual loading.
If an attempt is made to transmit a secure message without loading the corresponding key,
“KEY FAIL” is displayed. The message must then be transmitted in the clear mode (this is
possible only if the channel is strapped to “switchable”) or the key must be loaded.