ELECTRONIC UPDATING

TM 11-5820-890-10-8

ELECTRONIC UPDATING

4.8.

Sending TEK by Over-The-Air-Rekey (OTAR) Procedures

4.8a.

Only TEK may be transmitted over the air using the OTAR procedure.

RESTRICTION

KEK may be distributed by physical means only.

There are two procedures by which aTEK may be sent over the air. One

TWO WAYS

is called Automatic Keying (AK); the other is Manual Keying (MK).

The MK OTAR procedure allows an NCS to transmit a TEK from a

MANUAL KEYING (MK)

source ANCD, through the SINCGARS radios, to one or more target

ANCDs. This is a useful form of OTAR in that the receiving NCS can

then distribute the new TEK to net operators by passing the ANCD

through the unit.

The AK OTAR method transmits the new TEK from the NCS radio

AUTOMATIC KEYING (AK)

directly into the target operators' radios. An advantage of the AK

method is that the receiving operator is required to take no action at all.

A disadvantage is that the TEK and KEK in the receiving radios are

changed immediately while the sending NCS must reload that radio

with the new TEK and an updated KEK. This procedure involves some

risk of losing communications, at least in secure mode.

To send a new TEK to other NCSs by using the MK OTAR process, the

SENDING MK OTAR

sending NCS operator follows the steps shown in Figure 4-14, below

(also see Special NCS Task 3, "Send TEK to Other NCSs Using MK

Method of OTAR," for detailed procedures):

Prepare radio to send MK OTAR: FCTN to SQ ON,

(1)

MODE to FH-M, COMSEC to CT and DATA to

OFF.

Load receiving stations KEK into NCS radios

(2)

channel 6.

Prepare ANCD to send MK OTAR: turn ANCD ON,

(3)

enter Radio, Comsec, MK, select TEK.

Connect ANCD to NCS RT using fill cable.

(4)

Direct target NCSs to standby, make special NCS

(5)

task 5 preparations, and ACK when ready for MK

OTAR.

Direct target NCSs to set RT to chan 6; press

(6)

[RCV].

Set NCS RT to channel 6 and press [SEND].

(7)

Return to operational channei.

(8)

After 30 seconds, announce OTAR complete, TEK

(9)

ID is xxxxx, effective DTG is xxxx, and obtain ACK.

Reload KEK in NCS radio; MK OTAR is complete.

(10)

Figure 4-14. SENDING MK OTAR

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