Spy sets
Burst encoders
Logo (click for homepage)
Data Transfer Device - Wanted item

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 DS-101 and DS-102 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 [7]. 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.
AN/CYZ-10 in operation

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 SINCGARS, KY-57 (VINSON), KY-99, KG-84, KIV-7, etc.

The AN/CYZ-10 was designed to replace older devices like the KYK-13, KYX-15 and KOI-18. 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.
Closed CYZ-10 unit Rear view of the CYZ-10 showing the U-229 FILL connector Front view of the AN/CYZ-10 CYZ-10 with separated CIK AN/CYZ-10 in operation Close-up of the keyboard Close-up of the ON/OFF button Close-up of the ZEROIZE button (press 3x to purge all keys)

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 compartment.
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.
Replacing the three 3V cells

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.
Using a standard 9V block battery Close-up of the a standard 9V battery Replacing the three 3V cells Close-up of battery holder Close-up of battery holder with three 3V batteries Connection terminals, protection diode and fuse Battery holder placed inside the CYZ-10 Closed battery compartment

The AN/CYZ-10 was developed by the US National Security Agency (NSA) [1] in the early 1990s and was first produced by AlliedSignal from 1993 onwards [4]. In 1999, after AlliedSignal merged with Honeywell, the production was taken over by Group Technologies Inc. in Tampa (Florida, US) [5]. 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) [6]. 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 [6].
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 [6].
  1. Wikipedia, CYZ-10
    Retrieved May 2012.

  2. Headquarters, Department of the Army, AN/CYZ-10 User and Maintenance Manual
    Technical Bulletin, TB 11-5820-890-12. 1 April 1993. Approved for Public Release. Unlimited distribution. Retrieved May 2012.

  3. Brooke Clarke, AN/CYZ-10 5810-01-343-1194 Data Transfer Device
    Description of the device. Retrieved May 2012.

  4. Wikipedia, AlliedSignal
    Retrieved May 2012.

  5. Sypris Electronics website
    Retrieved November 2011.

  6. US Army, New Data Transfer Device mission grows
    9 September 2008. Retrieved May 2012.

  7. Datakey Electronics, Memory Availability
    Info Sheet about the various crypto keys (CIK) produced by the company.

Further information

Any links shown in red are currently unavailable. If you like this website, why not make a donation?
Copyright 2009-2013, Paul Reuvers & Marc Simons. Last changed: Sunday, 27 May 2012 - 21:34 CET
Click for homepage