FED-STD-1023, FEDERAL STANDARD: TELECOMMUNICATIONS: INTEROPERABILITY REQUIREMENTS FOR ENCRYPTED, DIGITIZED VOICE UTILIZED WITH 25 KHZ CHANNEL FM RADIOS OPERATING ABOVE 30 MHZ (25 SEP 1989)

FED-STD-1023, FEDERAL STANDARD: TELECOMMUNICATIONS: INTEROPERABILITY REQUIREMENTS FOR ENCRYPTED, DIGITIZED VOICE UTILIZED WITH 25 KHZ CHANNEL FM RADIOS OPERATING ABOVE 30 MHZ (25 SEP 1989)., This standard establishes interoperability requirements regarding the analog to digital conversion, encryption (with related synchroniza tion), and modulation of encrypted voice associated with Frequency Modulation (FM) radio systems employing 25 kHz channels and operating above 30 MHz. In this standard, voice is digitized using 12 kbit/s Continuously Variable Slope Delta -modulation (CVSD) and then encrypted using a National Security Agency (NSA) Commercial COMSEC Endorsement Program (CCEP) Type I encryption algorithm.