Cipher Machines Through History
This website tells the story of the ingenuity and advancement of cipher technology throughout
history. Maybe even more ingenious is the development of code-breaking technology and espionage in order to counter those
advances. The winners in this intellectual arms race enjoy a huge advantage on the battlefield or in the spy vs.
spy world of a cold war.
As an example, the German Enigma machine was quite an advancement in technology prior to WW2,
but the Nazi confidence in its invincibility caused them to
ignore some obvious signs of code-breaking. Likewise, the Japanese trusted the integrity of their "Purple Cipher"
despite warnings from the Germans the code had been breached by the US. So both the Germans and
the Japanese believed their own ciphers were secure throughout WW2 but both were broken by the Allies, which made a
significant difference in the outcome of WW2. Breaking the Nazi Enigma code also spurred the development of modern
computing and the first computers.
The US also used a rotor based cipher machine in WW2, named the M-209 and designed by Boris Hagelin. This cipher was
broken by the Germans, but the US was aware of this possibility and only used this machine for tactical messages.
Interestingly, the most secure cipher in WW2 was the low-tech "analog" cipher the Navajo Code Talkers used, which
was speaking in their native language. The speed and security of this cipher was unmatched by the latest and greatest
technological innovations from any country.
The most successful cipher machine after WW2 was sold by Boris Hagelin through his Swiss company, Crypto AG. In
1952, he started selling an improved rotor-based cipher machine to 120 countries which was much more secure than the
previous design used by the US military and was called the CX-52. Another reason for his success was
due to the perception of neutrality offered by having his company based in Switzerland. In the mid-1970s, an
electronic cipher machine was introduced with a "back door" access put in by the US NSA, allowing the US unfettered
access to the world's secrets for several decades.
The story of the "Clipper chip" is a little-known intrigue of the most far-reaching proportions. In 1994, the US government
attempted to
require all US manufacturers to install this chip with a proprietary cipher algorithm designed by the NSA in all communications
devices, phones, PCs, routers, switches, etc. This would give the US government a public "back door" into all communications.
The only devices ever built with this technology were some AT&T phones, which you can see from my collection.
This egregious
intrusion into personal privacy was thwarted at the last minute by two major developments. Matt Blaze, working for the only
company to have a product with this chip, found a vulnerability in
the Clipper chip which allows a user to disable the ability of the government to recover the key needed to decipher the message.
Before the government could correct this vulnerability, a new cipher algorithm was offered as open-source code and was quickly
adopted by many companies around the world.
This software was modestly (or maybe ironically) called PGP for Pretty Good Privacy, which is still in use today. This brazen
attempt by the US government to trample the privacy rights of its citizens has never been widely reported, but luckily the
codebreakers won this battle.
As far as we know, the current public key cipher systems are secure. They are all based on the one-way mathematical function
of finding the prime factors of large numbers. Multiplying two large prime numbers is easy, finding the factors of the
resulting number is
not as easy. Currently, there is no known algorithm to find the prime factors of a large number and a brute force attack is
also not feasible with current computer speeds. So the coders now have the advantage unless a mathematical way of finding
prime factors is discovered or until massively parallel computing is developed, such as with DNA computing. Who knows, we may
find out 30 years from now that the US or some other government had this technology all along. This is not paranoia,
just a reasoned study of history, which has shown the pendulum will eventually swing to the side of the codebreakers.
Most of the information on this website will be presented in the form of pictures and presentations to tell the story of this
ongoing arms race. Almost all the pictures are from my personal collection of cipher and communications equipment, including
a Nazi Enigma machine, US M-94 cipher wheel, US M-209 ciphers, CX-52 & CD-57 Hagelin cipher machines, Navajo code talker radio,
rare Japanese field radios, RT3 Burst Encoder, the Clipper chip cipher and other modern ciphers. I have attempted to provide
very detailed, close-up photos showing the internals of each of these machines.
The pictures and words on this website are copyrighted, but permission is hereby granted to copy and use any of this content as long
as it is for non-commercial use and is attributed to CipherMachines.com.
Types of Cipher Machines
Caesar Shift Cipher
One of the earliest recorded examples of using ciphers was employed by Julius Ceasar in communicating with his
generals. This cipher was also the simplest, reportedly a shift of the alphabet by 3 characters, so an "a" was
enciphered to a "d", a "b" was enciphered to an "e", etc. This shift of characters remained constant throughout
the message and is therefore classed as a monoalphabetic cipher. The solution for this type of cipher, even if the alphabet
is mixed randomly, is considered trivial.
Vigenère Cipher
The Vigenère cipher was named for Blaise de Vigenère, even though it was invented by Leon Battista Alberti in 1467,
56 years before Vigenère was born. It uses a Caesar cipher with a different shift at each letter in the text, with the
amount of the shift defined by a repeating keyword. This is an example of a polyalphabetic cipher and was commonly
considered unbreakable even into the 20th century. Keywords shorter than
the message (e.g. "Complete Victory" used by the Confederacy during the American Civil War), introduce a cyclic
pattern that could be decoded using letter frequency analysis. In fact, the Union regularly decoded the Confederate
messages. Pictured is a Confederate cipher disk, only five of which are known to exist.
Jefferson Cipher Wheel & US M-94 Cipher
In the 1790s, Thomas Jefferson invented the "wheel cypher" as he called it, which was a stack of 36 wooden wheels mounted on
an axle. Each wheel was unique, with a different random alphabetic arrangement on its circumference. The order of each of
the wheels on the axle gives the number of possibilities for the key, which is 36!. For a small
number of short messages, this is considered a very strong cipher, even today. This picture shows the oldest cipher device
known to exist, found in a home near Jefferson's mansion in Virginia, which looks exactly like the description given by
Jefferson. Jefferson's invention was lost to history, until discovered in his papers in 1922. Coincidentally, it was
independently re-invented and entered service in the US military in that same year and remained in active use until 1942.
Nazi Enigma Machine
The Nazi Enigma machine is undoubtedly the most famous cipher machine in history. This machine, first offered
commercially in 1923, looked like a typewriter keyboard with a light panel to display rather than print the output.
It used three interchangeable rotors to encipher each letter of a message multiple times with a different cipher
alphabet. The Polish and later British and then US cryptographers successfully broke the code, which had a significant
effect on the outcome of WW2. Despite 11,000 people in Britain and several thousand in the US working on deciphering
the Enigma, the secret of the code being broken was not disclosed for almost 30 years, in 1974. An estimated 100,000
Enigma machines were made but now only about 200 are known to exist, of which 70 are in private hands. This is a
collector's item for the über-geek. See close-up pictures of the
internals of one of those 70 machines here.
Japanese Purple Cipher
The Japanese Purple Cipher was the diplomatic cipher used by Japan before WW2 and then used by the military
throughout the war. This cipher is similar to the Enigma machine and was broken by the US even before the war
started. A Japanese diplomat in Germany used this cipher to report back to Japan the Nazi preparations and
arms placements to counter the Allies plans for D-Day. The US knowledge that their deception of landing site
had worked was a major factor in their confidence to proceed. No intact Purple cipher machines are known to
survive the war, pictured is a remnant from the Japanese embassy in Berlin recovered in 1945. The Japanese were
told by the Germans that Purple was broken by the US but they refused to believe this until after the war. It
was in public Congressional hearings into who in the US government had warnings about the upcoming attack that
the Japanese finally discovered their Purple cipher was broken throughout the war.
Navajo Code Talkers
During WW2, the US Marine Corps deployed the American Indian tribe of Navajos to provide "analog" enciphering of
military messages. They would talk in their native language and add code words for military terms and armament
for which they did not have a translation. For instance, they used "iron fish" to mean "submarine" or "hummingbird" to mean
"fighter plane". They were able to cipher, send and decipher a 3 line message in 20 seconds, the less-secure
M-209 required 30 minutes. Pictured is the radio used by the Navajo Code Talkers, the ultra-portable TBY radio.
US Army M-209 Cipher
Boris Hagelin developed a mechanical cipher machine that used a series of rotors combined with a "pin and lug" mechanism to
allow each character of a message to be enciphered many times. The US military purchased 140,000 of these devices, named
the M-209, for use during WW2. The US was aware the Germans broke the code, so the use of this machine was limited to
tactical battlefield messages. By 1943 the M-94 wheel cipher was phased out and replaced by the M-209. Despite being
less secure, this cipher did have some advantages over the Enigma on the battlefield. It was light, small, did not need
battery power and provided a paper strip printout so it could be operated more quickly and by one person.
Hagelin CX-52 and CD-57 Ciphers
In 1952 Hagelin designed an improved version of his cipher machine called the CX-52, which became the most successful
cipher machine in history, selling to the military, diplomats and commercial companies in 120 different countries. A hand-held
version was called the CD-57, which was compatible with its larger brother but small enough for spies and other portable
requirements. Basing his company in Switzerland gave an aura of neutrality and precision Swiss engineering, allowing
his company to have the confidence of all the countries in the world. It turns out this confidence was betrayed by
Hagelin, a later electronic cipher machine was introduced in the 1970s which had a "back door" access inserted by the
US NSA, giving the US unfettered access to all the world's secrets for several decades.
RT3 Burst Encoder
Burst encoders were important tools for the spies or commandos working behind enemy lines. The RT3 is a post-WW2 West German cipher
and burst encoder combined, developed by the BND (West Germany's CIA). You can store up to 25 numbers at a time, requiring the
messages to be in code. By attaching the burst encoder to a small, hand-held radio and manually cranking the drum, a coded message
is enciphered and sent as morse code at a fraction of a second. It is capable of sending 750 wpm, earning the descriptor of "burst".
Not only is the message in code, it is sent in such a short burst the enemy has a hard time picking up the correct signal or finding
the spy by direction finding. Of course, most messages required multiple bursts to go across the airwaves.
Modern Ciphers
Modern ciphers use the power of computing for very secure and user-friendly cryptology. In fact, the enciphering
and deciphering is accomplished without the user even aware it is occurring. In addition to the message privacy the
previous cipher machines attempted to provide, modern ciphers add two additional features. They now authenticate
(the sender is who he says he is) and provide data integrity (the message has not been altered). An example of this
technology is pictured showing a Cisco Systems 2621 router with a Crypto VPN hardware module. Also, you will see the
world's first routers, the Cisco AGS+, CGS, IGS, etc.