TB 380-41
3.6.1 (U) Requests for Key Tapes. Some cryptosystems are capable of local key generation (i.e., KY-57, KY-58, and KG-83), in electronic form, for distribution to cryptonet holders without resorting to hard copy key (see NAG 16[XXX]). Local generation of electronic key is the preferred method for operations whether derived from key generation-capable COMSEC equipment, or via the LCMS
Workstation. When field generation of key is not a viable option, key must be ordered in hard copy form. Ordering key in tape format requires the commander and COMSEC personnel to be familiar with three different types of key: Traffic Encryption Key (TEK), Key Encryption Key (KEK), and start-up KEK.
a. (U) Ordering Tape TEK.
(1) (U) Uses. For nets/circuits that distribute TEK via Over-the-Air Re-key (OTAR), tape TEK serves two purposes.
At Network Control Stations (NCSs) that derive OTAR TEK from certified KG-83/KGX-93s irregular superseded tape, TEK serves as emergency back up in case of a KG-83/ KGX-93 failure. At NCSs that do not use field-generated TEK, tape TEK is required. Tape OTAR TEK associated with OTAR is not dedicated to any specific net, circuit, or COMSEC equipment. In that
application, a short title of appropriately classified key tape can serve as the source of TEK for any or all nets and circuits that are controlled by an NCS.
(2) (U) Format. Tape TEK intended for use on nets/circuits that distribute TEK via OTAR is produced in the “V_” format, indicating that each canister contains 62 segments. The second letter of the digraph identifies the cryptoperiod, which may vary with specific
applications. See the appropriate KAO to determine approved cryptoperiods.
(3) (U) Copy Count. Only one copy is produced of each edition of tape TEK intended for use on nets/circuits that distribute TEK via OTAR, since the using NCS is the only holder. Each alternate NCS should hold its own short title(s) of one-copy tape TEK.
Non-OTAR TEK can have as many copies as the CONAUTH requests.
(4) (U) Supersession. At the discretion of the CONAUTH, tape TEK may be re-supplied on a regular or irregular basis.
(a) (U) Irregular. In most tactical
applications, the consumption rate for tape TEK is not accurately predictable.
For example, a commander who has been designated as a possible NCS for a particular start-up KEK may not serve in that capacity for a long period, or tape TEK held as back up for a stand-alone (non-TRI-TAC) KG-83 may never be used. In applications like this, CONAUTHs should order reasonable quantities of tape TEK.
Each edition of this key should be superseded irregularly. If follow-on editions are needed, allow four months for production and delivery. The recommended procurement strategy is to requisition as many editions of a single short title of tape TEK as may be required for each using NCS or alternate NCS. Where tape TEK is held only as back up, the
recommended stock level is one month’s worth of expected use. That period should be long enough to requisition and obtain a replacement KG-83.
(b) (U) Regular. In applications where its use rate can be predicted, the number of 62-segment TEK tape canisters required to meet an NCS’s requirement, and the schedule on which they are re-supplied, are inter-related. This requires that the
CONAUTH adjust the number of short titles and their supersession schedules to ensure that the required volume of tape TEK is received. For example, if an NCS expects to use 150 segments of tape TEK per month, the CONAUTH should order three
monthly-superseded short titles.
TB 380-41
b. (U) Ordering Tape Start-up KEK.
(1) (U) Use. Start-up KEK tape supports the establishment of temporary tactical nets and circuits secured by 57, KY-58, KY-67, KYV-5, KY-99A, KY-100, KIV-7, or KG-84A/C equipment. Any commander may order a start-up KEK tape for use by an identified community of potential users. Requestors should allow four months for production and distribution.
(2) (U) Format. Start-up KEK tape is produced in the “VA” format (62 segments – daily cryptoperiod).
(3) (U) Copy Count. The copy count in which a start-up KEK tape is requisitioned should provide for the expected number of holders and a reasonable number of spare copies to accommodate unplanned additions to the cryptonet. The CONAUTH must designate where spare copies are to be held.
(4) (U) Supersession. Each edition of start -up KEK tape is regularly s-uperseded at two-month intervals.
c. (U) Ordering Tape KEK. Where physical distribution of keyed fill devices is operationally viable, KEK should be field-generated. However, since many tactical environments require use of tape KEK, guidance for ordering tape KEK is as follows.
(1) (U) Use. Tape KEK, rather than tape start-up KEK, should be used on KG-84A/C, KY-57/58/67, and KYV-5/KY-99A/KY-100 secured nets and circuits
that exist on a continuing basis and that distribute TEK via OTAR.
(2) (U) Format. Tape KEK (except that which is used with KW-46) is produced in the
“GF” (16 unique segments – three month cryptoperiod) format. Since only four segments per edition are used each year, the remaining segments are available for cold starts. When a cold start is required, the next segment in the canister will be used. At the end of the quarter, simply pull the next available segment.
(3) (U) Copy Count. In point-to-point applications and nets that use a unique KEK for each net member (i.e., nets that OTAR sequentially), the copy count for each edition of tape KEK is two. In nets that OTAR simultaneously, the copy count corresponds to the number of net members. The CONAUTH may order a few extra copies to accommodate possible future cryptonet expansion;
however, they must designate where such extra copies will be held.
(4) (U) Supersession. Each edition of tape KEK associated with continuing nets and circuits are superseded annually. Tape KEK associated with contingency applications may be requisitioned with irregular supersession, but this places the burden of ensuring continuing resupply on the CONAUTH. In either case, four months should be allowed for production and distribution of tape KEK.
d. (U) Guidance for Ordering Key Tape.
The following table provides standard recommendations given by system type and digraph (for more information on digraph, see 4.8.1a).