The First Compiled History of the KL-7

TSEC/KL-7 © Dirk Rijmenants

The TSEC/KL-7 was the first rotor cipher machine to use electronics, and although the KL-7 had excellent cryptographic properties, its track record is what made this machine a true Cold War icon. My first encounter with that curious unknown machine with vacuum tubes was back in 2005, displayed behind glass on the battleship HMS Belfast in London.

It took another six years to unravel the inner workings of this cryptologic beauty, and write the first accurate KL-7 simulator. This was only possible thanks to the release of many technical documents from the National Security Agency (NSA), through Freedom of Information Act requests (FOIA's) from Bill Neill, and published by Nick England from US Navy Radio Communications. The technical expertise from Paul Reuvers and Marc Simons from the Crypto Museum, and from George Mace, were also instrumental to develop the KL-7 simulator.

However, despite the release of some history related documents, only fragmented pieces of its development and operational use were available, and the history of the KL-7, initially named AFSAM-7, remained largely unknown to the public. In the last three years, I could connect more dots, found in the NSA's William Friedman records.

Historical records from the U.S. Army Security Agency (ASA) contained production details, planning and procurement, and later described the analysis of the KL-7's use in Vietnam. Those records were preserved by the NSA. The NATO archives revealed the use of the KL-7 by many allied countries and some of their state departments, and the technical support they received.

Although there were only unconfirmed hints that the KL-7 was also used by the CIA and FBI, some tiny bits of information provided clues on where and how to search for more information. Moreover, ASA records confirmed the procurement for those agencies. That search took long, but eventually led to a few CIA documents and multiple FBI files that confirmed their own use of the KL-7, and its use by the White House and some Asian countries.

The KL-7 also had its own chapters in the history of Cold War espionage, with chief warrant officer John Walker selling the machine's technical details and secret keys lists to the Soviets, but the Counter Intelligence records from the Director of National Intelligence (DNI) also detailed warrant officer Joseph Helmich's betrayal, leading to other FBI files on counterintelligence operation Hookshot to catch Helmich. His case is less known than John Walker's, but just as interesting.

Ever more pieces of information were added to the KL-7 webpage, which already contained all technical information, making it quite large. To make the KL-7 history more accessible, I decided to publish the article that I started in 2022, which also includes references to the relevant ASA, AFSA, NSA, NATO, FBI, CIA and DNI files. This way, everyone can easily find all related files for their own research.

Since my motto is "history is here to share", you're free to share or publish the below document, or parts of it, provided that proper credits are added. Why should you share it? Because its use across the world for decades, and the spy cases, make the KL-7 a true Cold War icon that deserves its place in history, but also to honor the cryptologists and engineers who developed this marvel, and the operators who served around the world, lest we forget.

History of the TSEC/KL-7 ADONIS & POLLUX - The first standard U.S. tactical lightweight rotor cipher machine using electronics

If you're also interested in how the machine works, its development and full history, then visit the TSEC/KL-7 page at the website.

Call to Veterans! If you operated or maintained the KL-7, we're always interested in your experiences with the machine, to expand its history. We're not interested in classified information, only stories about where and how you worked with the KL-7 (the machine is declassified). Since the KL-7 retired 40 years ago, time is running out to preserve personal testimonies. Help us preserving history!

Crypto Tour – Discover Real Crypto Websites

Click to start tour

What is Crypto? These days, you won’t even get the correct answer from Google. Instead, you get hundreds of hits on "crypto" currency websites, top ranking on Google because they promise you to get rich in the shortest time, or lose your money just as fast. Crypto, the short for cryptography, is none of that. 

 

In fact, the term crypto, used since the 1840s, has nothing to do with so-called "crypto" currencies. No worries, we will lead you to real crypto websites. Spoiler for those who want to get rich. No coins, no profits, we’re talking non-commercial websites about cryptography, how it works, the equipment and history. The good news is that you don't need to be a geek or math wizard, you will discover all kinds of fascinating stuff and won't lose a dime. History is there to share.

Since Google ranks virtual currencies higher than science, a chain of links, called the "Crypto Tour", will guide you through a series of selected websites,  created by cryptography experts, enthusiasts and historians from around the world. They bring you the real story of crypto. All participating websites have the same Crypto Tour icon (in varying colors or size) on their main page. Whichever website you visit, you can always click that icon to discover other crypto websites. To get started, click the above icon to visit our website, find and click the Crypto Tour icon and discover other excellent crypto websites.

For those Gen Z people who mistakenly think crypto is a currency, cryptography is the study and implementation of techniques to hide information or to protect it from being read. The information can be written text, electronic signals or digital information. It’s counterpart is cryptanalysis or crypto-analysis, the study and analysis of existing ciphers and crypto algorithms, in order to assess their quality, to find weaknesses or to find a way to reverse the encryption process without having the key, i.e. codebreaking (see brief history).

If you want to earn good money, and love math, know that cryptologists are in high demand. There are many job opportunities in today's digital world. You don't have to apply for a job at NSA,  GCHQ or CSE, but if you're smart enough, why not? Start the Crypto Tour and click the Crypto Tour icons to find related websites.

 

Or you could check out the video below and take your chance with some "crypto" coins (no pun intended ;-)

Self-help Singh - Crypto: a short talk on self-induced anxiety
(find more advice and life lessons:)

Computers and Cryptography

The development of computers is closely intertwined with the history of cryptography, and vice versa. The mechanization of cryptography during the early 20th century slowly began to exceed the skills of cryptanalysts to break such encryption. The only way to break these ciphers was to also mechanize the breaking of ciphers. Colossus, the first programmable digital computer, was developed exactly for that purpose during World War II.

Until the early 1950s, computers were only used by government agencies for codebreaking, the military, weapons development and research. In 1951, the UNIVAC was the first commercially produced digital computer, but computers were mainly used by universities and large corporations like IBM and General Electric. Programming those large mainframe computers was a complex task.

Making Computers Accessible 

This changed when Professors John Kemeny and Tom Kurtz from Dartmouth research university  got the, I quote, crazy idea to develop a simple language to make programming easier and more accessible for non-technical undergraduate students.

However, they first had to buy a computer. Since there was no budget for computers, they bought a Librascope LGP-30 computer, an optical tape reader and a typewriter console for a total of $37,040 and booked it under furniture. That's $383,434 in present 2023.

Librascope LGP-30 with console typewriter. Source: Bob Fleischer - Wikipedia.

John Kemeny wrote the compiler to translated the new language into machine language for the LGP-30. This new language was named BASIC (Beginners' All-purpose Symbolic Instruction Code) and made programming easier than ever.

Moreover, to make BASIC accessible to as many students as possible, they implemented time sharing  (sharing computing resource) on the LGP-30 computer to enable several students to independently work on their own console typewriter, remotely and simultaneous, processed on one single computer. This idea resulted in students lining up  to learn programming with BASIC, the computer language that remains popular to this day.

Crypto Going Mainstream

For many people, BASIC was their first programming language when small computers became commercially available in the late 1970s. This was the era where people who bought a computer usually also learned to program. They were often called nerds, because… who on earth needs a computer? Yeah, sure.

The rapidly growing number of computers and users also spurred the development of crypto algorithms by others than government and the few commercial firms that build crypto equipment. This fueled the everlasting competition between codemakers and codebreakers, and between state and citizens. This evolution also democratized cryptography and digital privacy.

All this started when two professors decide to make programming easier. More on the development of BASIC in the below video.

 
Birth of BASIC - Dartmouth College

More on Cryptography and Computers

On our website you find a brief history of cryptography and learn more about the Colossus computer, used by the British codebreaker during the Second World War to break the German Lorenz SZ40/42 machine, used for their high-level communications.

More on the LGP-30 computer at the Computer Museum Stuttgart and many detailed photos at the Time-Line Computer Archive. Also read Fifty Years of BASIC on Time.

Mission: Impossible - Cyber Security

Cyber security is an ever-evolving battle that we can never win. The reason is simple. Virtually no one actually knows what is running on their computer at this very moment. And yes, that's a bit scary.

Gary Ruddell created a series of videos that are both entertaining and professionally made. His website provides insight in cyber security and includes articles, a newsletter and also workshops for those who are interested in a career in cyber. Here's one of his videos.

Here's Why Cyber Security is Impossible - Gary Ruddell

 

Secure communications is indeed quite complex. Luckily, there are professional firms that provide secure solutions. At least, that is what we expect them to do. However, the former Swiss firm Crypto AG had a hidden agenda, as I explained in previous posts. Garry also created a perfect introduction video about the shady adventures of that firm.

The Greatest Hack of All Time - Gary Ruddell

 

You can visit Garry's website at www.garyruddell.com to learn more about cyber security. Make sure to visit his Youtube channel to discover more videos. Highly recommended.

RN Communications Branch Museum/Library

HMS Mercury
Royal Navy Signals School

Sometimes you need serendipity to discover a fascinating website. I researched the TSEC/KL-7 cipher machine for long and was able to find the few declassified documents on this 1950s cryptologic gem that served until the early 1980s.

Initially named AFSAM-7, the KL-7 was developed for all US armed forces, but the US Navy developed its own fully compatible version with a few more options, named AFSAM-47, later designated KL-47.

Unfortunately, little is known about the British use of the KL-7. However, NATO documents linked patrol boats, minesweepers and submarines to the KL-7 instead of the naval KL-47. This is how the search engine keywords KL-7 and Navy, and a bit of serendipity, lead me to the RN Communications Branch Museum/Library.

This fascinating website is a private initiative of Ken Sutton, who served from 1966 until 1998 in the Royal Navy (RN) and retired as Warrant Officer 1st Class. He then served as civilian Communications Training Design Officer until 2012.

RN Comms Museum History  

The museum/library has existed since the late 1800s when the RN Signal School was based in the RN Barracks Portsmouth, now HMS Nelson base. In 1941 the Signal School and its library moved to the HMS Mercury shore establishment near Petersfield, where the library was maintained and a small museum was established.

HMS Mercury closed in 1993 and moved into HMS Collingwood shore establishment in Fareham. Unfortunately, no space was allocated for the Mercury museum and library, leaving all exhibits kept in cupboards and drawers. The Royal Navy Signals history comprises several branches and specific expertises, of which the communicators were the workforce, and still are today.

The badges of Tactical, Women's Royal Naval Service and Telegraphist/Sparkers

The first badge (crossed flags) is the Tactical badge, the branch that dealt with all comms by flashing light, semaphore, flag hoists, with expertise in the manoeuvering of ships. This side of the branch was transferred to the Seaman Specialist branch circa 2004. 

The second badge (blue gold wings) is the Telegraphist/Sparkers badge of Women's Royal Naval Service (WRNS) Communicators from the era that WRNS served mainly in shore communications centres worldwide. Few were morse trained and most trained in message handling. They also were trained to encipher and decipher messages using various systems. Notably, they also made up the majority of GC&CS personnel in Bletchely Park during WWII. They eventually integrated in the RN and now serve aboard navy vessels, informally still known by the nickname "wrens".

The third badge (gold wings) is the Telegraphist/Sparkers badge of the branch that dealt with all radio communications.  Today, this branch is referred to as the Communication and Information Systems branch (CIS) due to the amount of computerised systems used in the communications world.

Preserving History   

When Ken Sutton retired in 2012, he volunteered to set it all up again.  The museum is not an official RN museum, even though it resides in a naval establishment.  He created the website to make the museum's exhibits and documents available to all RN Communicators past and present without having to travel long distances to visit it.

His small website turned into a major project when Jeff Dykes, a former Warrant Officer Radio Supervisor, requested Ken to incorporate his huge online archive about all things Navy into the RN Comms Museum website. That's where I found the first account from Royal Navy personnel on the KL-7 and its use.

The website has a huge collection of technical information about naval communications, transmitters and receivers, technical drawings and photos, but also about how the Royal Navy is organised, from information on submarine warfare to burial at sea. You name it, and there's a page about it. Now, back to the KL-7...

The RN Comms Cryptography page describes in detail the KL-7 and its early use in the Royal Navy. More about the KL-7 and how it was used at the Cold War Cryptography page.

Do visit the RN Communications Branch Museum/Library and make sure to check out the Sparkers and Snippets menus, each of which has several sub-menus with many more pages, hundreds! Use their Search Page to find specific items in the vast collection.

Highly recommended!