Data Transfer Device
The AN/CYZ-10 is a portable data transfer device
used by the US Military and NATO for the distribution of cryptographic
keys and other data between cryptographic devices and secure communication
equipment. It was developed by the US National Security Agency
(NSA) in the early 1990s and supports the
protocols for transferring cryptographic data.
The device is housed in a black plastic case and weights less than 2kg.
When closed it measures approx. 16 x 11 x 5.5 cm. The image on the right
shows a typical CYZ-10 with its top lid open. The lid contains a
Liquid Crystal Display (LCD), whilst the bottom part contains a rubber
key pad with 35 keys arranged in a 7 x 5 matrix.
At the left rear is a typical 6-pin U-229 key fill connector
that can be connected to the FILL-socket of a crypto device or a secure radio
system by means of a suitable key fill cable.
At the front left is a slot for a Crypto Ignition Key (CIK).
Keys of this type are made by Datakay Electronics in the US and contain
an EEPROM .
When in use, the EEPROM is loaded with a so-called Key Encryption
Key (KEK) that is used to encrypt the Traffic Encryption Keys (TEK) inside
the unit. Without the CIK, the TEKs are useless.
The AN/CYZ-10 is also known as Data Transfer Device (DTD),
Automated Net Control Device (ANCD), Crazy-10,
and by its National Stock Number NSN 5810-01-393-1973.
It receives its crypto keys from an Army Key Managent System (AKMS),
any other key generator, another CYZ-10 or any other key transfer
device that supports DS-101 or DS-102.
It can hold up to 1000 keys in its battery-backed memory
and is suitable for transferring 128-bit keys as used by many US
COMSEC and INFOSEC devices, such as
The AN/CYZ-10 was designed to replace older devices like the
The price of a refurbished unit in 2005 was $4000. From 2006 onwards, the
CYZ-10 was gradually being replaced by newer devices, such as the
PYQ-10 Simple Key Loader (SKL)
and the Secure DTD2000 System (SDS),
the latter of which is running on the Windows CE™ operating system.
The CYZ-10 is powered by an internal 9V power source, consisting of
three standard 3V photo batteries, such as the Duracell DL123A.
At the bottom of the unit is a small rectangular lid that is held in
place by 4 bolts. Removing the 4 bolts gives access to the battery
Inside the battery compartment is a plastic frame that can hold
the three 3V batteries, producing a total voltage of 9V.
This voltage is also used to retain the crypto keys stored in
the unit's static RAM. The battery holder has two standard 9V
battery clips at one side, allowing a common
9V block battery to be used as an alternative
in case you run out of standard batteries.
The image on the right shows the battery holder once it is removed from
the CYZ-10. In order to protect the unit against reverse polarity,
a diode and a glass-fuse are mounted inside the holder.
When in standby, the unit consumes less than 0.12 mA.
According to the manual, the batteries should be replaced every month.
In practice however, then can be used much longer if the unit is used
less than one hour each day.
When the CYZ-10 is stored for a longer period of time,
it is recommended to remove the batteries.
Without batteries, the keys are lost after 2 minutes.
The AN/CYZ-10 was developed by the US National Security Agency
 in the early 1990s and was first produced by
AlliedSignal from 1993 onwards . In 1999, after AlliedSignal merged with
Honeywell, the production was taken over by Group Technologies Inc.
in Tampa (Florida, US) . Group Technologies was a subsidary of Sypris
Solutions Inc (Louisville) and was later renamed to Sypris Solutions Inc.
Around 2005, Sypris stopped the production of the AN/CYZ-10 and moved production to the Windows-based Secure DTD2000 System (SDS).
In March 2008 production of the AN/CYZ-10 was taken over by the Secure
Telecommunications Branch of the Tobyhanna Army Depot in Pennsylvania (US)
. Existing devices are reburbished here and new PCBs and case shells
are made locally at the Tobyhanna Army Factory. Over 1000 units were produced
in the first year, with a more dan double estimate for the following year.
Close to 6000 people are employed at Tobyhanna, which is located
in the Pocono Mountains of Pennsylvania. It is the largest
center for repair, overhaul and fabrication of the US Army .
Unfortunately, we can not show the interior of the CYZ-10.
The unit featured in the photographs was only briefly available to us
and the case can not be opened without permanent damage. This is because
the two case-shells are welded together with ultra-sound. In practice,
defective units were sent to Tobyhanna (see above) where they
received a new case as part of the repair .
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© Crypto Museum. Created: Saturday 26 May 2012. Last changed: Sunday, 11 March 2018 - 13:06 CET.