Voice Scrambling/Encryption - Icom IC-FR5100 Series Handbook

Voice scrambling function
The optional voice scrambler unit provides high performance private communication between stations with the
same scrambler code. The 32 code non-rolling-type voice scrambler UT-109R and 1020 code rolling type UT-
110R are available.
Variable Split and Frequency Inversion
This is the scrambling system employed in the UT-109R and UT-110R. The audio frequency band is divided at a
specified frequency (divided frequency) and high and low audio frequencies in each band are inverted. The
divided frequency is programmable with cloning.
Original AF
Level
300Hz 3kHz Frequency
Difference between rolling and non-rolling types
The rolling type (in fact, hopping type is used for the UT-110R) is an additional feature which provides higher
communication security. It changes the divided frequency over a specified period.
Non-Rolling Type (UT-109R)
Dividing Frequency is fixed
with programming
Level
300Hz
Dividing Frequency
Low
Digital Voice Encryption Function
The IDAS system provides a 15-bit key (about 32,000 keys) encryption for secure communication.
Digital Audio
Υ
1 0 1 0 1 0 1 0
Key
4-7

Voice Scrambling/Encryption

Dividing
Dividing Frequency
Level
300Hz
3kHz Frequency
High
TX
Encryption
Inverting
Level
3kHz Frequency 300Hz
Rolling Type (UT-110R)
Dividing Frequency is
Level
changed over specified
period
300Hz
Dividing Frequency
Low
RX
Decipher
Dividing Frequency
3kHz Frequency
3kHz Frequency
High
Digital Audio
Υ
1 0 1 0 1 0 1 0
Key
34