The KG-40/40A is a half-duplex digital device used to provide cryptographic security protection for the Navy Link 11 system and any data communications meeting Tactical Data Information Link (TADIL) A data standards. It links the computer and the data terminal set. The KG-40A serial configuration (KG-40A-S) is used in the Airborne Tactical Data System (ATDS) and the parallel configuration (KG-40A-P) is used in the Navy Tactical Data System (NTDS).

The KG-40A is a mandatory modified version of the older KG-40, which incorporates variable fill capability. The modification entails replacement of a printed circuit board (motherboard) and the front panel assembly. The KG-40A provides enhanced security using an improved cryptographic algorithm and electronic key capability. Because the KG-40A key is a standard 128-bit key, it can only be keyed by the AN/CYZ-10 Data Transfer Device (DTD) or a KOI-18 Common Fill Device (CFD). It cannot accept key from the KYK-13 Keying Device (ETD) or from the KYX-15 Net Control Device (NCD). The KG-40A is an UNCLASSIFIED controlled cryptographic item (CCI) when unkeyed and is interoperable with the KG-40. When the KG-40A is keyed, classification equals that of the key installed. The KG-40A peripheral equipment includes the MT-4417/S Parallel Mount, MT-4416/A Serial Mount, and KGX-40A Remote Control Unit (RCU).

The KG-40AR is a functional and physical drop-in replacement for the (now obsolete) KG40 and KG-40A COMSEC devices, developed and produced by Ultra Electronics Ltd. in the UK around 2004, for the US Department of Defence (DoD) and NATO. This is the first time in history that the US Department of Defence (DoD) has procured a Type 1 cryptographic system from an offshore company [2]. The KG-40AR is based upon Ultra's Multi Link Processor (MLP) and the BID/2200.

CHARACTERISTICS

PHYSICAL

POWER

KG-40A(S): 120 Vac ±10%, 45 to 65 Hz or 380 to 420 Hz, single phase, 26W
KG-40A(P)  120 Vac ±10%
 

ENVIRONMENTAL

KG-40A(S)
    Operating Temperature:
                       -54 to 71 °C (continuous operation)
                       -54 to 95 °C (intermittent ½ hr max.)

UNIT PRICE:  No longer produced
 
 
 

Although the KG-40A is no longer in production, the units were still widely used in the field in 2015 . In 2014. it was announced that they would be succeeded by the British KG-40AR.

KG-40AR

 
The image above shows a typical KG-40AR unit, which has the same form factor as the KG-40A it replaces. The standard U-229 fill port is at the bottom left. It is compatible with the DS-102 and DS-101 data transfer standards. Just above the FILL connector is the FILL-MODE selector.

In 2004, the US Navy awarded Ultra Electronics in the UK a US$ 2.4 million contract for the development of the KG-40AR. It would be based on Ultra's proved Multi Link Processor (MLP) which incorporates Ultra's BID/2200 cryptographic module that has been in use with the Royal Navy since 1999. The BID/2200 is approved by the Communications Electronics Security Group (CESG) of GCHQ, and also used by NATO. The KG-40AR is currently in use (2015) and was still in production in 2014. It is backwards compatible with the older KG-40A and (modified) KG-40.

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Credits and Contributors

1)  Source: US Navy COMSEC web page: https://infosec.navy.mil/TEST/PRODUCTS/CRYPTO
2) http://www.cryptomuseum.com/crypto/uk/kg40ar/index.htm
 
 

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Mar 4/15