A key transfer device is an electronic device that is used (most commonly
by the military) for the distribution of cryptographic variables, such as
crypto keys and frequency hopping tables.
Key fillers often use a standard data protocol,
such as DS-102
or DS-101 — both endorsed by the
USNational Security Agency (NSA) —
but devices with proprietary protocols are also common.
FILL devices are known under different names:
Electronic Transfer Device
Key Transfer Device
Key Fill Device (KFD)
Common Fill Device (CFD)
Data Transfer Device (DTD)
Key Fill Gun
Key Filler
Key Loader
Fill Device
Fill Gun
Filler
FILL
Fill units that follow the DS-101/102 protocol,
are generally equipped with a U-283 connector
— the 6-pin version of the U-229 —
allowing them to be connected directly to crypto devices and standard US
radio sets, such as HAVE QUICK
and SINCGARS. The same standard is also used
on devices from a wide variety of other manufacturers,
including Philips, Siemens,
ANT and Harris.
Key fillers are commonly used for the distribution of the
Transmission Encryption Keys (TEK)
and Transmission Security Keys (TSK),
such as Frequency Hopping (FH) tables.
The latter is also known as Electronic Counter Counter-Measures (ECCM).
Fill devices are also used for the distribution of Key Encryption Keys (KEK).
Fill devices are used for:
Most devices that support the NSA's
DS-101
or DS-102 protocol, use the
same 5-pin or 6-pin AUDIO connector, commonly referred to as U-229/U
or simply U-229.
It has a standard pinout,
but is different for each protocol. Click the
image below for more information. ➤ More
Key Storage Device
As an alternative to key fill devices in the shape of an external box,
modern electronic cipher machines sometimes use a
Key Storage Device (KSD)
in the shape of a plastic toy key.
One example is the NSA-developed
KSD-64,
that is used with the
Motorola SECTEL STU-III phones.
The KSD-64 can be configured for use as Fill Key (FK)
and many other key types.
DS-101
This is the most recent transfer protocol that is used with the
current generation of FILL devices, radio sets and encryption equipment.
It superceedes DS-102 and can be used for transferring crypto keys,
frequency hopping data, software updates, etc.
➤ More
DS-102
This is a synchronous serial protocol that was used with the first
generation of Key Fill Devices, such as the KYK-13.
It is the predecessor of the DS-101 protocol, and
can be used for the distribution of key material and frequency hopping
tables.
➤ More
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