Crypto Machines

© Brooke Clarke, N6GCE 2002 - 2024

Manually operated Cipher Devices
Voice encryption  Devices
    TCC CSD 909
GPS using crypto key
    Ashtech Ranger
    DAGR PSN-13
    PLGR PSN-11
    Quantic Q5200
Analog Data encrypting
Digital Data encrypting
     FS 5000
    Harris KGV-72
Fill Devices
        KOI-18 Paper Tape
     Fill Hardware
    Over The Air Re-keying (OTAR) aka Automatic Remote Keying (SARK) 
    Red & Black Keys
    Electronic Serial Number (ESN)
Test Equipment
Algorithms & Protocols
Key Management


I have never worked with crypto machines and do not have access to any classified information.  No classified information appears on this or any of my other web pages.  All the information is from open sources such as the internet and non classified manuals.

Wiki: NSA encryption systems - NSA cryptography (keywords like "Have Quick" (Wiki), JOSEKI (CryptoWiki), SAVILLE (Wiki), VINSON (Wiki) -
Wiki: Cryptographic algorithms - Cryptographic protocols -


M-94 25 wheel Cipher Device (Wiki)

M-94 is the U.S. Army nomenclature, CSP-488 is the Navy name.
The M-138-A is a strip cipher version.

The Jefferson Disk (Wiki) aka: Bazeries Cylinder (Wiki)  works on the same idea, but is much older.

Manual operation. Simple construction.
Used through the end of W.W.II.


Got the crypto bug from reading The Ultra Secret by F.W. Witherbotham.  It told about breaking the Enigma machine.  I've wanted one of these since then (1975) but real machines are very collectable (expensive) so never got one.  Did get the Enigma-E kit to make a functional machine, but it does not have the look and feel of a real machine.  The Enigma I shown here is a non functional machine that does have the look and feel of a real enigma machine.

This came from Spain.  Maquina Enigma - This is the Enigma I model.
White Collar TV series (Wiki, IMDB): S2-E16 "Under the Radar" booby trapped Nazi Submarine & Enigma Machine - Preview@0:20 -

Fig 1 Spain to California took a tool
But no damage to Enigma.
2024Feb6: will improve.
Maquina Enigma I
Fig 2
Maquina Enigma I
Fig 3
Maquina Enigma I
Fig 4
Maquina Enigma I
Fig 5 Rotor cover hinges open
Maquina Enigma I
Fig 6
Maquina Enigma I
Fig 7
Maquina Enigma I
Fig 8 Inside Lid
Maquina Enigma I

GRA-71 Coder-Burst Transmission Group (British GRA-71 for the PRC-316)

Magnetic tape holds a short message that is sent using 300 Word Per Minute Morse code (Burst transmission (Wiki).  Can be used with the GRC-109, PRC-64, Delco 5300, PRC-74, PRC-316, PRC-319, PRC104 & probably most modern radios that support CW operation.
Manual operation.
Used through Vietnam conflict.


KYV-2 Secure Voice Module

Used with the PRC-68 Family of hand held Squad Radios, Digital 16 kbps
Should inter operate with the KY-57 (ground) and KY-58 (airborne) systems
Post Viet Nam.
VINSON (Wiki) voice encryption system  (Wiki)

KY-38 Man Portable Secure Voice System

Works with the PRC-77 but not the PRC-25.  Mechanical key loading.
Should inter operate with the KY-8 (Vehicular) and KY-28 (airborne)
Used through Viet Nam.
NESTOR system replaced by VINSON.

KY-57 Voice Transmission Security Device

Used with a large number of radios for both voice, fax and data.
Late Vietnam.
VINSON system (Wiki)

KY-65 Voice Encryption Unit 

Used with PRC-104 and other H.F. radios.
? mid to late Vietnam (same box as PRC-25 and PRC-77)
Parkhill system.

KY-68 Secure Field Phone

Not much is known. 
What encryption system, what will it interoperate with? Let me know.

KY-99 Advanced Narrowband Digital Voice Terminal (ANDVT)

Wiki: ANDVT,
Replaces the KY-57 and other equipment.  Requires new interconnecting cables.

MSC-2001 Voice Encryption Unit (VEU)

Uses a 40 character key based on 5-level paper tape.  Originally designed to work with the PRC-77.

TCC CSD 909 PRM Communication Security Device

Uses thumb-wheel switches to set key.
Should work on any radio via audio input & output.


Ashtech Ranger

Key loaded from KYK-13.


Has an Over The Air Rekeying (Wiki) capability and individual serial number.
There may be a shut down function that works by unit serial number.

PLGR AN/PSN-11 GPS Receiver

Can use a crypto key for reception of the GPS L2 frequency.

Quantic Q5200 GPS Time Receiver

Can use a crypto key for reception of the GPS L2 frequency.

Trimble SAGR, AN/ASN-169

Version of the Trimpack that decodes encrypted L1 to avoid problems when SA was turned on.
Requires key load for encrypted signals but works as civilian receiver without keys.

Analog Data

KY-864/U Encoder-Decoder

An aircraft module for encoding and decoding digital to analog. Probably no crypto function although nomenclature is KY-...

Digital Data

There are a large number of crypto boxes used to encrypt/decrypt teletype transmissions.  This is the most common digital data application.


FS-5000 Spy Radio, uses I&Q modulation for Tx and Rx.  Most likely that the missing control box contains some type of encryption that would allow the spy to compose a message in the field and send it as well as decrypt an incoming message.  This would require inputting a key.  If the missing control box did not contain any crypto function it may not have been destroyed.

There's a plethora of crypto machines designed to encrypt/decrypt teletype transmissions.  That's an area that I'm interested in, but not one where I have a collection of equipment.
The most interesting one of those is the KW-7 Orestes (Jerry Proc) & KL-7 Adonis.   That's because I worked for TRW Microwave at the time the book "Falcon and the Snowman" (Wiki, IMDB, Amazon) came out.  Also the John Walker Family Spy ring (Wiki) caused the Pueblo to be captured so the Soviets could get these machines.

Harris KGV-72

Would use the Sierra II' crypto chip which is the basis of all the Type 1 cryptography.  But this is a new empty box.

Harris Red-Black Cryptographic device
Harris Red-Black Cryptographic device


Wiki "The KG-84A and KG-84C are encryption devices developed by the U.S. National Security Agency (NSA) to ensure secure transmission of digital data. The KG-84C is a Dedicated Loop Encryption Device (DLED), and both devices are General-Purpose Telegraph Encryption Equipment (GPTEE). The KG-84A is primarily used for point-to-point encrypted communications via landline, microwave, and satellite systems. The KG-84C is an outgrowth of the U.S. Navy high frequency (HF) communications program and supports these needs. The KG-84A and KG-84C are devices that operate in simplex, half-duplex, or full-duplex modes. The KG-84C contains all of the KG-84 and KG-84A modes, plus a variable update counter, improved HF performance, synchronous out-of-sync detection, asynchronous cipher text, plain text, bypass, and European TELEX protocol. The KG-84 (A/C) is certified to handle data at all levels of security. The KG-84 (A/C) is a Controlled Cryptographic Item (CCI) and is unclassified when unkeyed. Keyed KG-84 equipment assumes the classification level equal to that of the keying material used."

Installation Parts

AC Power Cord
KG-84 AC Power
KG-84 Circular to DB-25 Red/Black Adapter Box
                    Circular to DB-25 Red/Black Adapter Box
KG-84 Circular to DB-25 Red/Black Adapter Box Open
                    Circular to DB-25 Red/Black Adapter Box Open
U-229 - DB-9 Crypto Fill Cable
U-229 - DB-9
                    Crypto Fill Cable

KG-84 Circular to DB-25 Red/Black Adapter Cable
                    Circular to DB-25 Red/Black Adapter Cable

Military Radio Cryptographic Remote Control

Unknown application.

Fill (aka Key Loader)

There are a number of different things that can be filled.
Wiki: Glossary of cryptographic keys, Fill Device


Key Fill Devices (KFD)

There are two electrical formats for key fill.  DS-101 (the newer of the two protocols) like used with the CYZ-10 and DS-102 like used with the old KOI-18 paper tape reader.
I think the DS-102 uses six volt levels working from ground to a negative potential whereas the DS-101 uses TTL (zero and +5 V) levels (RS-485).

Note there are many key types (Wiki: List of cryptographic key types, Key Size) and the fill device needs to be able to handle the desired keys.

2019 October 22: Computer Business Review: EXCLUSIVE – Last Punched Tape Crypto Key Rolls off the NSA’s Machines -

KOI-18  5810-01-026-9620 Tape Reader General Purpose

DS-102 protocol.  The KOI-18 may be the oldest electrical key loader (the KY-38 used a mechanical key loader).  Used to load the Transmission Encryption Keys (TEK) into the KY-57 and  about anything that needs a key.  It uses a photo optical reader to read a paper tape that's pulled through the reader by hand.
Very versatile since what comes out depends on what is punched on the tape.  Other key loaders have electronic registers that can only hold keys in predetermined formats.

Manuals: TM 9-1425-429-12 or TM 9-1425-2586-10
TM 11-5810-292-13&P
Battery: 6.3 Volt BA-5372/U (used to be the 6.5 Volt Mercury BA-1572/U)
Supports 128 bit keys (actually any length paper tape that someone can pull through the machine)
KOI-18 drawing KOI-18 Fig 10
                      5810-01-026-9620 Tape Reader General Purpose
Fig 12
                      5810-01-026-9620 Tape Reader General Purpose
Fig 13  8-level tape (Wiki)  is 1" wide.
                      5810-01-026-9620 Tape Reader General Purpose

Fig 14 Note grouped as 3-space-5.
The space is where the sprocket holes are.
                      5810-01-026-9620 Tape Reader General Purpose
Fig 15 The rod with the blue tape seems to be made of carbon and is the common ground for the wire fingers that sense the 8 data holes.  Note there is no sensor for the sprocket holes.
                      5810-01-026-9620 Tape Reader General Purpose

TM 11-5810-292-13&P General Purpose Tape Reader, KOI-18; Elect Transfer Device, KYK-13; Net Control Device, KYX-15/15A

I've heard that it uses 8 level ASCII type tapes rather than the older 5 level Baudot tapes.  Note that the data holes are larger in diameter than the sprocket (clock) holes.  This is important since the leading edge of the sprocket hole can be used to latch the data bits and the trailing edge of the sprocket hole can be used to shift out the data bits.  This would not work if all the holes were the same diameter.
In the old mechanical tape readers, like on the Teletype Corp. Model ASR33 machine, there was a plastic wheel with pins that match the sprocket holes and it pulled the tape through a reader that worked using mechanical pins to sense each data hole.
Inside there's probably a parallel in - serial out shift register.  The parallel inputs are driven from the data holes. The shift register data is latched on the rising edge of the sprocket hole and on the falling edge a pulse generator sends 8 clock pulses which are used both to clock out the shift register data bits and to provide the clock signal to the device being loaded.  The clock rate needs to be fast enough to get all the bits sent before the next set of holes gets to the tape reader.

If the tape was pulled at 3 feet per second and the pitch of the data was 0.1" then there would be 360 words per second (8 bits per word) or an average rate of 2,880 bits per second, so the internal clock generator needs to run faster, say 5,000 bits per second.

If the operator pulls the tape too fast the bits will get corrupted.  To check for this the tape needs to be punched with parity, Cyclic Redundancy Check (CRC), check sum or some other data to be sure the correct key gets loaded.  This is not a part of the key loader, but instead is part of how the data is punched into the tape. This check can also be used by the the device holding the key to tell the difference between no key and a valid key.  The device being loaded should not function without a valid key and it's cold start state should be such that it is recognized as a no key state.  For this reason even parity is not a good way to go because a key of all zeros would have even parity.  If odd parity is used a key of all zeros fails a parity test.

Note that an asynchronous data system, like RS-232 that uses start and stop bits will not work with a hand pulled paper tape reader because the baud rate can vary over a huge range.  This is why a synchronous system is used that has data and clock channels.  Newer key loaders that are not paper tape based continue to use the data plus clock format for backward compatibility.

"COMSEC equipment description
General purpose tape reader, KOI-18/TSEC, controlled cryptographic item (CCI).
The National Security Agency (NSA) has directed that a fill cable be connected to the fill device when transferring a key.

KOI-18 tape reader, general purpose.
(a) Battery operated, hand-held device.
(b)Converts eight-level standard paper and mylar tape to serial electronic information.
(c) Loads keys from prepunched tape to other COMSEC equipment, KYK-13 or KYX-15.
(d) Has no storage capability.
(e) Tapes are normally generated ahead of time and stored for later use.  May be distributed by mail or courier."
There is no limit to the key size since it will just read whatever is on a tape.

There are two very major problems with this system.  First the amount of key material is gigantic and the logistics of getting the keys where they need to be is a huge task.  Because the keys need to be made at NSA well before they are used they are vulnerable to being copied or compromised anywhere along the path to the end user.  This has happened more than once during the cold war.

One attempt has been made to secure the key tape between it's generation and use is a canister that claims to prevent returning a key tape.
4108390 Paper tape canister, Hugh V. Hayes, Secretary Of The Army, Aug 22, 1978, 242/588.6, 242/615.3, 225/52 -
4768693 Canister opener, James E. Tomaszewski, Sep 6, 1988, 225/94, 30/363, 30/120.3, 380/59 - to allow inspection prior to disposal

The KLL -1 is a more modern version of the KOI-18 made in Germany.  (Crypto Museum: KLL-1)

KYK-13  5810-01-026-9618 Electronic Transfer Device

Fig 0
KYK-13 drawing
Fig 1
                    5810-01-026-9618 Electronic Transfer Device
Fig 2
                    5810-01-026-9618 Electronic Transfer Device
Fig 10
                    5810-01-026-9618 Electronic Transfer Device
Fig 11 UV flashlight
                    5810-01-026-9618 Electronic Transfer Device

DS-102 protocol.  This electronic key device looks very similar to the MX-18290 and is designed to hold TEKs and so replace the KOI-18.  THe KYK-13 is smaller than the MX-18290.
Uses the common crypto battery BA-5372/U.

Holds 6 TEK variables.

20 Aug 2004 - there is some confusion about what key size the KYK-13 can hold.  The PLGR can use the KYK-13 to load its GPS key which is 128 bits long.  But other references say the KYK-13 can only hold a 64 bit key.  I think it's 128 bit keys.

Instructions for loading key from paper tape (KOI-18) into KYK-13:
1. Connect the LOI-18 to the KYK-13.
2. Turn the KYK-13 selection knob to the desired buffer.
3. Open the latch on the LKOI-18.
4. Insert the paper tape (printed side up) into the slot marked IN.
5. Turn the KYK-13 command knob to ON.
6. Push the load INIT switch on the KYK-13.
7. Pull the paper tape thorough the KOI-18.
8. Turn the KEY-13 command knob to OFF.
9. Press the load INIT switch on the KYK-13.  If the key was loaded successfully, the load indicator light on the KYK-13 will flash. (same as when loading a key into user equipment)
10. If more keys are needed to be loaded, turn the selection knog on the KYK-13 to the desired buffer, and startr again at step 3.

KYX-15    5810-00-026-9619 Net Control Device

KYK-15 drawing
DS-102 protocol.  Don't have much info in this Net Control Device, but it can load a TEK.
Powered from a BA-5372/U
Does support KY-57.  See
TM 11 5820-890-10-3 pg 102 (3-20).
TM 11-5810-292-13&P

KYX-15A  5810-01-095-1312 Net Control Device

TM 11-5810-292-13&P

Probably can hold different types of predefined variables and can load more than one variable because a switch allows selection of those that need to be loaded.  This would make loading all the different variables into a modern SINCGARS radio much easier that with the above key loaders.

The VG switch position may mean Crypto Net Variable Generation, so this device actually generates a key.  Used to load all the KY-57's on a SINCGARS radio net. 

It must support 128 bit keys.
Fig 10 Small black and white wires
that have been cut as part of de-mill process.
                      5810-00-026-9619 Net Control Device
Fig 11
                      5810-00-026-9619 Net Control Device

Local Key Generation

Note that local key generation is a revolutionary concept.  All prior keying methods depended on distribution of keys that were centrally generated.  The problem with that is a spy (Walker Family for example) that gains access to the unused keys can comprise the whole system.  In order to generate local keys requires a high quality hardware random number generator based on a noise diode or some other physical noise mechanism, not on any software algorithm.  When a network of SINCGARS radios have their keys loaded using Over The Air Rekeying (OTAR) from the KYX-15() you know that the keys have not been compromised.

9 Switch positions:
  • SEL-Z to zero selected slots
  • OFF/CK for power OFF and for ChecKing a slot to see if it holds a valid key,
  • LD for LoaDing a key into the KYK-15 or from the KYK-15, which direction depends on which device has it's initiate "load me" button pressed,
  • VG for Variable Generation,
  • AK for Auto Keying of a remote variable slot that holds a valid key,
  • MK for Manual Keying a remote variable slot that is either empty or holds an obsolete key,
  • RV for Remote Variable for filling the KYK-15 from a remote source over a radio, (same as RV on KY-57)
  • VU for ?
  • ALL for zeroizing all slots (with manual lock button)
Nice Photos of a KYX-15

AN/CYZ-10  5810-01-343-1194 Data Transfer Device

CYZ-10 DTSDS-101 Protocol.  Data Transfer Device (aka ANCD, aka "Crazy 10") that holds all the keys needed for the SINCGARS and also holds Standard Operation Instructions (SOI).
Battery:  DL123A, U9VL EMER ONLY, BA-3090/U - this is the very common 3 volt 123 photo battery.
Supports 128 bit keys.

This is the newest variable loader and it can hold all the different key formats now used and other stuff.  It's internal clock is not good enough to set the time in a frequency hopping radio like the SINCGARS or Have Quick radios, not because of dropping battery voltage, but because it uses a crystal oscillator.  All crystal oscillators change frequency with aging, temperature, power supply voltage, and other factors.

SINCGARS Fill cable is CX-13467, NSN 5995-01-379-9689.  Note that the SINCGARS needs a number of different fills for both frequency hopping and for transmission security.

It's not clear if the Crazy 10 supports key generation.  If not it needs a modification to support key generation.

The Crazy 10 uses 3 each common 123 photo batteries (aka BA-5123/U) in a battery adapter (NSN 5810-01-348-3147) that has standard "9 Volt" battery snaps.  This way a common 9 Volt battery can be used if the 123 batteries are not available.  But the common 9 Volt battery has only 0.6 AH compared to the 1.4 AH of the 123 battery.  Also the cold temperature performance of common 9 volt batteries is very poor at and below freezing where the 123 battery is still going strong.
PS Magazine #571 pgs 48-51 - Beating the Battery Blues.
TB 11-5810-394-12  Generic Equipment Information and Instructions for the AN/CYZ-10 V3 (NSN 5810-01-393-1973) Data Transfer Device (DTD)
TM 5820-890-20-2 Chapter 6 Fill Devices
TB 5820-890-12 Operator and Unit Maintenance for AN/CYZ-10 Automated Net Control Device (ANCD) NSN: 5810-01-343-1194 (EIC: QSU) with the Single Channel Ground and Airborne Radio Systems (SINCGARS)


AN/PYQ-10 Crypto Fill Device

This is the replacement for the CYZ-10.  Looks sort of like a hand held PDA.  It would be interesting to learn how good it's internal clock is.  i.e. can it be used to set the date and time or is a seperate GPS still needed? Ans: the PYQ-10 clock is the same as the Crazy-10 clock.  Too bad they didn't improve it.  I think I know how to make a 1,000 times improvement for a small amount of money.

Key Length

 from a now turned off Navy web page.
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 Electronic Transfer 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.
(BC - note the KYX-15 above is the no change version, probably the KYX-15A does support 128 bit keys.)

CRC & other ways to confirm the Key loaded correctly

There needs to be a way for the device that's holding the key to know that the key has been loaded without errors and maybe that it's the proper type of key for that device.  For example there are a number of different devices that use keys of the same length.  Loading a valid key for device "A" into device "B" might not be correct.

The first test parameter would be the overall length of the key, i.e. some number of bits.  The next in terms of simplicity would be a parity check, i.e. is the sum of the "one" bits in an 8 bit byte or a 16 bit word even or odd.  Note that a key of all zeros or all ones, like would be there at first power up, has even parity, so using odd parity will tell you that there's something there other than an all zero key.

The next level of checking would be a Cyclic Redundancy Code (Wiki).  This is a check to be sure that there are no single bit (or more depending of the details of the particular CRC used) errors in the key.  It's appended to the end of the actual key.

A Painless Guide to CRC Error Detection Algorighims Index V3.00 (9/24/96) -
Cyclic Redundancy Check (CRC) -

A feature of some CRC methods is that you can append zeros onto the input data and run the algorithm to get the CRC bits which are then used to replace the zeros.  Now when the block that includes the data and appended CRC bits is run through the algorithm the result is a zero byte.

It may be the case that instead of filling the to be determined CRC location with all zeros you can fill it with any number and get that number when running the CRC on the data plus CRC.  For example if placing zeros results in a zero CRC result, placing 1 might result in a 1 CRC result.  If that works then you could have 256 different CRC flavors if the CRC was a single byte.  These could be used to identify the type of data the key contains, for example is it a voice security key or is it a GPS key, how long is the key good, etc.

Over The Air Re-keying (Wiki: OTAR) aka SAVILLE Automatic Remote Keying (SARK)

The KY-57, SINCGARS and a number of other systems support the OTAR concept.  The key being sent is encrypted with a Key Encryption Key (KEK) with equal to greater security than the key it's encrypting.  The encrypted key (the black key) is sent over the air.  Although anyone may receive the black key it does them no good without knowing the KEK.  The receiving equipment decrypts the black key into a usable red key inside the equipment.  End use crypto equipment is designed in such a way that you can not get the red key as an output.  Fill devices are designed to load but not unload red or black keys.

In the NSA paper A History of U.S. Communicatios Security (Vol 1 1973 and 2 1981),  the David G. Boak Lectures, NSA (pg 113) there is a little discussion about SAVILLE Automatic Remote Keying (SARK).  SAVILLE is part of the keying system implemented in the KY-57 which was the first equipment to have this capability.  There are two schools of thought as to why it was done.  One is that it was done to solve the huge logistics problem of supplying the needed key material.   The other is that it was done to reduce the occurrence of keys that get to the enemy, for example John Walker (Wiki).

A problem with OTAR (aka: SARK) was that the military had been trained to not leave active (keyed) equipment unattended or not locked up, so it was common for users of the KY-57 to zeroize the box at the end of each day.  That means there must be a nearby key fill device to reload it the next day.  So operationally it really didn't pan out.

The DAGR GPS receiver has OTAR capability but with a new twist.  It has a unique Electronic Serial Number (ESN) like a cell phone.  The DAGR is only classified to the level of the key that it's holding so a DAGR without a key is not classified allowing it to be supplied without all the red tape that hardware classification entails.  It is however a Controlled Cryptographic Item (CCI) and must be accounted for.  This appears to be a solution to the OTAR problem since the crypto variables could be remotely erased from a unit that was unaccounted for or was known to be stolen or captured. 

But if the designers of the DAGR had been a little cleaver they would include a low power transmit capability in the DAGR which can only be activated from the GPS.  The signal would be a spread spectrum signal, similar to the GPS signal, but not interfere with GPS and could be received by either the GPS satellites or some other ELINT type satellites.  An analysis of the Black Box showed that this is very possible.   This way a stolen receiver could be queried and report it's position, sort of like Lojack (Wiki).

The use of ESNs in crypto equipment has obvious benefits so I expect it's already being done.

Red & Black Keys

Red Keys

When a Red key is combined with it's crypto system the plain text information is accessible.  Since the cipher text and the crypto systems are in the public domain the Red key needs to be well controlled to protect the information.  There are two major problems associated with protecting Red keys.  First, it takes a long logistics chain to supply authorized users with the keys they need.  That long logistics chain causes the second reason, the Red keys are prime targets of spies.  An example is the Walker Spy Ring (Wiki).

In addition to the Red key itself there is also how the key is handled in hardware.  If the Red key or data can be tapped in the hard ware then it still may be captured.  For example GPS receivers with the Precision Positioning Service - Security Module (PPS-SM) such as the SLGR or PLGR process the Red key and output plain text to the rest of the receiver.  That plain text could be tapped and recorded allowing someone to then key other like GPS receivers.

Black Keys

Black keys are Red keys that have been encrypted with a Key Encryption Key (KEK).  Black keys can be freely distributed and even transmitted over radio channels.  The use of black keys solves some of the problems of Red keys.  My grandmother had a saying "Don't put all your eggs in one basket".   The idea is that if the basket is dropped you loose all the eggs.  The analogy being if the enemy somehow gets the KEK then all of the Black keys can be turned into Red keys.

But if the crypto equipment converts the black key into a red key or into plain text information then capturing keyed equipment opens the door to getting all the plain text in the system.

If the hardware does not expose the red key or plain text then the use of black keys is much more secure.  That's probably the main reason the PPS-SM is being replaced with the Selective Availability/Anti-Spoofing Module (SAASM) (Wiki). 

Electronic Serial Number (ESN)

The DAGR GPS receiver also has an Electronic Serial Number (ESN).  The ESN is hidden in the SAASM hardware chip (not like a cell phone where it can be forged).   This allows messages specific to that GPS receiver to be sent.  I'm guessing it's similar to an IP address.  If so then black keys could be sent to a group of GPS receivers from the GPS satellites.  The problem I see with doing it is there needs to be some way that you know all the receivers being re-keyed are in the possession of authorized personnel.  If that's not done then there's a chance  you will be re-keying a unit in enemy hands.  Also you probably can erase all the currently loaded keys.

Fill Hardware

The modern crypto equipment no longer uses punched cards but the KOI-18 paper tape reader is still the most versatile in terms of supporting various key types since it does not have any built in protocol dependencies.  The two serial fill protocols are DS-101 and DS-102.  Neither of the specs are in the public domain.
DS-101 is based on RS-232 (asynchronous, i.e. just bipolar data and ground, no clock).
DS-102 is based on a negative polarity key fill protocol that uses a data and clock line.

MX-18290 Fill Device for early RT-1439 SINCGARS radios Hop set

Not used for voice security.

CV4228 PC to SINCGARS Fill Cable

Fill Cable - not sure, but probably. 

NSN 5810-01-066-7587 is an official fill cable.


Some of the SINCGARS manuals refer to the W4 as an Audio/Data/Fill cable.  It's wired 1:1 on 6 contacts of the AUDIO connector.

U-229 Family Connector

Taking a look at how this connector is used for: Audio, Fill, Data and Retransmission.

KD-100 Key Tape Disintegrator

For the destruction of paper or plastic key tapes

Test Equipment

USM-481 VINSON Interconnect Test Set

Used to check the cables and junction boxes in a VRC-12 series vehicle installation.

 F91120 BER Test Set

Used to measure the Bit Error Rate of a channel where VINSON will be used.

Hardware Random Number Generator

An idea would be to use a diode noise source and after amplification drive a PIC micro controller.  The PIC would look at two successive data bits and if they were the same get two more.  If the input was 10 a 1 bit would be shifted into a byte, if the input was 01 a 0 bit would be shifted into a byte.  When the byte was full it would be stored and after say 8 or 16 bytes were stored they would be sent out an RS-232 data port.  By using the noise diode and NOT using an algorithm the numbers would be nearly random.  But using the simple algorithm described any bias is removed and the resulting data stream is truly random.

A refinement would be to take the 8 or 16 bytes and pass them through something like the Tiny Encryption algorithm to really mix them up.  But it's not clear that this really buys anything when compared to the simple way.

hardware white noise generator -gain of 1000 x voltage following a noise source drives the digital input of a PIC microcontroller.

Algorithms & Protocols

An algorithm is how you get from plain test to the cipher text. They are categorized by how secure they are with Type 1 being the best.
NSA encryption algorithms (Wiki)

A protocol has to do with the layers below the algorithm down to the physical layer.
Cryptographic protocols (Wiki)

For example the KY-57 Voice Encryption unit is a Type 1 product that makes use of the SAVILLE algorithm (Wiki 128 bit key).  It's a member of the VINSON family of products that can interoperate which includes the KY-57, KY-58, KY-68, KY-99a, KY-100, KYV-2, FASCINATOR and SINCGARS or other radios with embedded VINSON capability.

 Type 1 NSA Certified cryptographic algorithms include:
 f) FIREFLY/Enhanced FIREFLY; and
g) JOSEKI Decrypt.  (Wiki) - a way to encrypt/decrypt computer programs

Type 2 cryptographic algorithms for use in communications systems endorsed by NSA.  These include classified algorithms.

Type 3 cryptographic algorithms for Sensitive but Unclassified information include:
a) DES, Triple DES;
b) AES;
c) Digital Signature Standard (DSS); and
d) Secure Hash Algorithm (SHA).

Exportable Type 4 cryptographic algorithms are Registered with NIST but not FIPS.

Key Management

List of cryptographic key types (Wiki)

a) SARK/PARK (KY-57, KW-5 and KG-84 MC OTAR);
b) DS-101 and DS-102 Key Fill;
c) SINCGARS Mode 2/3 Fill;
d) Benign KeylBenign Fill.


Communications Security and Related Equipment -
Crypto Machines by Jerry Proc - has pages for a number of machines
Cryptology Collections -
Voice encryption systems, VOCODERS - Sound Files for a number of systems
The Start of the Digital Revolution - Green Hornet aka SIGSALY W.W. II innovative voice encryption system
Collection of Things-That-Think -  Collections in Cryptology - One Time Tape Devices -
YouTube: CryptoMuseum: Using your STU II - 13:14 - STU II rekeying 0:53 -

Back to Products made by Brooke, Crypto, Crypto Patents, Military Audio, Squad Radio, Military Information, Home page

Page created 14 Dec 2002.

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NYTBook Review by David Kahn, Dec. 29, 1974: The Ultra Secret -