History of Hagelin Cryptos

HAQEUN-CRTPTOSI,
CRYPTO AG
The Story of the
HAGEUN-CRYPTOS
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THE STORY OF THE "HAGELIN CRYPTOS"
Page
Introduction
I.
II.
III.
The
The
V.
VI.
First
The
I V.
Beginning
B - 2 11
The
The
Machines
15
Machine
21
C-Machines
Te l e c r y p t o
Miscellaneous
Concluding
5
Machines
Machines
Observations
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3
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The Story of the "HAGELIN CRYPTOS"
INTRODUCTION
The "Story of the Hagelin Cryptos" could never have been written
if Russia after the revolution had become a democratic republic.
The expected defeat of the Bolshevik minority and the return
of a moderate government would have caused me to remain an
employee of the Nobel Brothers Oil Production Company, and
there would have been no CRYPTO AG - the present manufacturer
of ciphering machines.
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I was born on July 2nd, 1892 in Adschikent, a small summer
resort in the Russian Aserbeidjan. My father, a Swede who had
been born in St. Petersburg in 1860, was at that time manager
o f t h e N o b e l c o m p a n y ' s o i l fi e l d s a n d r e fi n e r i e s i n B a k u .
He had joined the company in 187 9 when it was founded by an
older brother of the famous Alfred Nobel. My father was made
a director of the company in 1899, and moved with his family
to St. Petersburg. I went to a Russian school until 1904,
w h e n m y f a t h e r s e n t m e t o a S w e d i s h s c h o o l . A f t e r fi n i s h i n g
t h i s s c h o o l I e n t e r e d t h e R o y a l Te c h n i c a l U n i v e r s i t y i n S t o c k
holm where I graduated in 1914 with a degree in mechanical
engineering. It was taken for granted that my future would
lie in Russia with the company, where my father held a leading
position and had become the closest friend of Emanuel Nobel,
h e a d o f t h i s f a m o u s f a m i l y.
M y fi r s t j o b w o u l d h a v e b e e n t h e s u p e r v i s i o n o f t h e c o n s t r u c
t i o n o f a n e l e c t r i c p o w e r s t a t i o n o n o n e o f t h e N o b e l o i l fi e l d s
i n B a k u . A s I w a s a m e c h a n i c a l e n g i n e e r, I h a d fi r s t t o b r o a d e n
my knowledge of electrical engineering. Nobels had ordered the
e q u i p m e n t f r o m t h e l a r g e fi r m A S E A i n Va s t e r a o s , a n d t h e r e f o r e
it seemed to be a good idea for me to work in different depart
m e n t s o f t h a t fi r m f o r a y e a r.
^
However, the Russian Revolution broke out, and it became obvious
that the project would have to be delayed until normal con
ditions returned. I thus stayed on at ASEA in their foreign
d e p a r t m e n t s i n c e I s p o k e fi v e l a n g u a g e s .
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In 1920 the Nobel family made an agreement with Standard Oil
C o m p a n y, N . J . f o r a f u t u r e c o l l a b o r a t i o n i n R u s s i a , a n d I w a s
sent to the USA where I worked in their general engineering
department during 1921. At the end of that year it became clear
that stable moderate conditions in Russia could not be expected
under the rule of the Bolsheviks, who had in the meantime con
fi s c a t e d a l l p r i v a t e e n t e r p r i s e s , i n c l u d i n g t h e N o b e l w o r k s .
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I could have stayed with Standard Oil, but I did not feel at
home in America and wanted to get back to Sweden. There was no
future for me in the oil business but my ties with Emanuel
Nobel remained unbroken. The Nobe.ls managed to retain their
non-Russian businesses, but had to live in exile, like my
f a t h e r.
Emanuel Nobel was very generous towards me and financed the
e s t a b l i s h i n g o f a s m a l l e n g i n e e r i n g o f fi c e i n S t o c k h o l m .
During my stay in the USA I had acquired some inventions,
which I developed which made me financially independent. The
decisive turning point in my life came, however, when Emanuel
Nobel entrusted me with the supervision of a small company
which he had begun to finance in 1921 — the A.B. Cryptograph.
This company was founded in 1915 with the objective to develop ^
and manufacture ciphering machines invented by the Swedish
engineer A.G. Damm. In 1925 I assumed the management of the
company as well as the development of saleable products. This
was a fascinating task although I did not have any knowledge
of cryptography. Mr. A.G. Damm died in 1927. In 1932 the A.B.
Cryptograph was liquidated and replaced by the A.B. Cryptoteknik.
A.B. Cryptoteknik manufactured only mechanical and electro
m e c h a n i c a l c i p h e r i n g m a c h i n e s . A f t e r Wo r l d Wa r I I t h e n e e d
for ciphered telegraph transmission became obvious. In order
to be able to work without the interference of the Swedish
Government -- ciphering machines were at that time considered
war material — I decided to move to Zug, Switzerland. I first
c o l l a b o r a t e d w i t h t h e S w i s s i n v e n t o r D r. E . G r e t e n e r, b u t l a t e r
established a small independent laboratory. CRYPTO AG was in
corporated on May 13, 1952, and had at first just one employee.
My Swedish activities were transferred to CRYPTO AG, and since
the name "Hagelin Cryptos" had already become well known before i
World War II the enterprise grew so fast that in 1966 a new
manufacturing and administration building was built in Zug/
Steinhausen.
The basis for the growth of the CRYPTO AG were the mechanical
machines, which were conceived and developed in Sweden -- the
o r i g i n a l " H a g e l i n C r y p t o s " . T h e fi r s t p r o d u c t s o f C RY P TO A G
w e r e t h e " Te l e c r y p t o s " . T h e y w e r e s u c c e e d e d b y t h e e l e c t r o n i c
ciphering equipment which have during the last six years become
predominant. The old mechanical machines are, in decreasing
quantities, still being produced. Without their basis, how
ever, the new developments which have culminated in a large
n u m b e r o f d i ff e r e n t v e r s i o n s w o u l d n e v e r h a v e e v o l v e d . T h e
trade name "Hagelin Cryptos" has therefore been applied to all
the different products of CRYPTO AG. It would be presumptious
for me to claim the credit for the success of CRYPTO AG,
h o w e v e r, i t w a s i n t e r n a t i o n a l l y a c k n o v / l e d g e d a s t h e m o s t
important manufacturer of ciphering equipment before I
retired from the company in 1970.
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The art of invention — and I have mainly become known as an
inventor — has for me been sudden ideas or the combination
of existing designs for totally different purposes. But the
h a r d d e t a i l w o r k t o o b t a i n t h e fi n i s h e d p r o d u c t s h a s b e e n
performed by many collaborators, for all of whom I retain a
sincere thankfulness. In this context I feel that I must
mention several names. First, CA. Lindmark, who became
indispensable to me when I developed my best known machine,
the C-type, in 1934.
My son Boris Jr., who met a tragic death in 1970, had an in
ventive mind, and his contributions when the postwar CX-type
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d e v e l o p e d m y o r i g i n a l i d e a s f o r t h e " Te l e c r y p t o " m a c h i n e s .
He also began to experiment with electronic ciphering devices,
a t fi r s t a g a i n s t m y w i s h e s , a s t h i s n e w t e c h n o l o g y w a s a l i e n
to me. To achieve success, however, it is not enough to have
a n e x c e l l e n t p r o d u c t b u t a l s o s u p e r i o r m a n a g e m e n t . H e r e , M r.
Sture Nyberg, who was first the manager and then the director
of CRYPTO AG until his retirement in 1976, proved to be the
ideal choice. He also contributed by analyzing the security
of the machines which were produced.
In closing this introduction I must pay my humble respect to
Emanuel Nobel and to my father, without whose financial and
moral support during the long and not always easy years of
m y w o r k w i t h c i p h e r i n g m a c h i n e s I w o u l d r e m a i n e d a n i n s i g n i fi
c a n t e n g i n e e r.
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:
Zug, Spring 1981
.
:
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I, The Beginning
The use of cryptographic methods of various kinds stretch
es back some thousands of years. A few hundred years ago
inventive minds began to make devices to facilitate the
process of enciphering and deciphering messages. In 1891
the Frenchman Etienne Bazeries invented a device (Fig. 1),
which to the best of my knowledge was still used until
World War II. The same principle used by Bazeries had been
propounded earlier by the third president of the United
S t a t e s T h o m a s J e ff e r s o n ( 1 7 4 3 - 1 8 2 6 ) f o r t h e c o n s t r u c t i o n
of a cipher device, but his writings were not discovered
u n t i l a f t e r Wo r l d Wa r I .
Fig. 1 Cipher Cylinder of General Bazeries
In Sweden too, interest existed very early in the use of
mechanical devices for secure communication. My old friend
S v e n Wa s s t r o m , a S w e d i s h c r y p t o l o g i s t , h a s d i s c o v e r e d i n
the national archives in Stockholm some very interesting
documents on this subject. In 1786 a Baron Fridric Gripenstierna received permission from King Gustav III to make a
cipher device in accordance with Gripenstierna's drawings.
In his "submissive" letter to the King, Gripenstierna
indicated that he had gotten the idea for the device from
h i s f a t h e r - i n - l a w, t h e c e l e b r a t e d i n v e n t o r C h r i s t o p h e r
P o l h e i m . T h e m a c h i n e i t s e l f , u n f o r t u n a t e l y, h a s b e e n l o s t ,
b u t t h e i n v o i c e ( F i g . 2 ) b y t h e b u i l d e r, w h i c h i s d a t e d
August 26, 1786, shows that the device was actually built.
A remarkably detailed description allowed CRYPTO AG to
produce a replica of this machine (Fig. 3a) .
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Fig. 2 Gripenstierna's Invoice
This device displays certain
much later by Bazeries but
far as security and method
intends to publish a study
few years.
resemblances to the one developed
far surpassed the French device as
of operation are concerned. Wasstr
of this earlier device in the next
Gripenstierna's device consisted of 57 disks, each of which
carried two alphabets. These disks, mounted on an axle, could
a l l b e r o t a t e d i n d e p e n d e n t l y o f e a c h o t h e r. A l o n g i t u d i n a l
slit with an index guide on each side of the device exposed
two sequences of letters. The authorized person who was to
perform the enciphering (at the right in Fig. 3b) adjusted
the disks during enciphering so that the plaintext appeared
row by row in "his" slit. The assistant (at the left in Fig.
3b) then copied down from the other slit the ciphertext, again
r o w b y r o w. D u r i n g t h e d e c i p h e r m e n t t h e a s s i s t a n t a d j u s t e d t h e
disks to show the ciphertext row by row in the slit on his
side. The authorized person then copied down plaintext row by
row from his slit. Here we have a modern security concept
which separates the ciphering process from the transmission
o f t h e c i p h e r.
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a
STOCKHOLM 17U
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Fig. 3 Cipher Machine of Gripenstierna
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In the 19th century inventors increasingly concerned them
selves with the development of ciphering devices and machines.
A n i n v e s t i g a t i o n s h o w s t h a t i n t h e G e r m a n p a t e n t o f fi c e , w h i c h
was founded in 1877, about 150 patents were issued before
1927 for cipher devices.
In this list the name of a Swede appeared in 1915: Arvid
Gerhard Damm. He was able to interest Swedish industrialists
in his inventions and A.B. Cryptograph was founded in 1915
to exploit his inventions.
H i s fi r s t f u n d a m e n t a l l y s o u n d m a c h i n e i s s h o w n i n F i g u r e s
4a and b. He used a revolvable drum, on which 26 alphabet
s t r i p s c o u l d b e fi x e d i n a n y d e s i r e d o r d e r. T h e a l p h a b e t s
were formed so that they could be considered to be a scramb
l e d Vi g e n e r e s q u a r e , w i t h t h e a l p h a b e t s i n r e v e r s e d o r d e r.
Close to the alphabet drum a reference alphabet in the nor
mal order (A...Z) was mounted (the dark strip).
When ciphering, the drum would be advanced one step for each
operation, while the reference alphabet could take one of
two positions (see Fig. 4b). Through a slit at the top of the
m a c h i n e ( F i g . 4 a ) o n e c o u l d r e a d o ff t h e l e t t e r s t o b e c i p h e r e d
from the reference alphabet to one of two drum alphabets. The
positions of the reference alphabet were controlled by the
chain (Fig. 4b) which advanced one step for each operation.
The low links set the referenced alphabet one operation,
w h i l e t h e h i g h l i n k s s e t i t t o t h e o t h e r.
The length of the chain and also the position of low and
high links could be varied within certain limits. These
options as well as the possibility of changing the relative
positions of the drum alphabets made it possible to obtain
a large number of different cipher series. The use of reci
procal alphabets made it easy to us,e the machine, as the
reading from the reference alphabet could be done both when
enciphering and when deciphering. Im emergency cases the
machine could be opened and the chaiin disassembled into the
individual links, thus destroying am important key element.
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Fig. 4 A-21 by Arvid G. Damm
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*
Using the same principle, Damm also built a number of office
machines equipped with keyboards. When a key was pressed, a
letter would be exposed below the alphabet strips. During
encipherment it would be a ciphertext letter, during de
cipherment the plaintext letter (Fig. 5).
Here too the chain was used as the controlling element. In
operation the machine was used with a protective cover.
Fig. 5 Office Machine by A.G. Damm (cover removed)
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He also constructed another purely mechanical machine which
printed both the plaintext and the ciphertext. Four of these
machines were sold to Japan. Finally Damm invented a system
with so-called rotors, i.e., alphabet permutating wheels,
an invention which was made at almost the same time by the
American Hebern, the Dutchman Koch, and the German Scherbius
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Fig. 6 "Mecanocrypto" by A.G. Damm
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* !
A normal rotor at that time consisted of a disk which had on
each of its two faces 26 metal contacts embedded around the
circumference. These contacts were connected in pairs through
the inside of the disk in a random fashion, one contact on one
face connected to one contact on the other face. The best-known
machine using rotors was the German "ENIGMA", equipped with
3 or 4 rotors which were set to a new starting position for
each message in accordance with the keying instructions. The
machine (Fig. 7) was provided with a keyboard and a lamp
field. Each lamp was arranged to light up one letter. To
operate the machine only a flashlight battery was needed.
*■■■■
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...._.
Fig. 7 "Enigma" produced by Chiffriermaschinen AG Berlin
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When a key was pressed, an electric circuit was closed so
t h a t i n e n c i p h e r m e n t t h e c i p h e r t e x t l e t t e r, i m d e c i p h e r m e n t
t h e p l a i n t e x t l e t t e r, c o r r e s p o n d i n g t o t h e k e y p r e s s e d w a s
lighted up. At the same time the rotors were moved step-bys t e p a c c o r d i n g t o a fi x e d p r o g r a m .
r
Damm1s rotors were constructed somewhat differently from the
ENIGMA'S but produced a similar effect. They were made for
machines which were intended for the ciphering of messages
t r a n s m i t t e d b y r a d i o t e l e g r a p h y, b e c a u s e s u c h m e s s a g e s c o u l d
easily be intercepted.
Damm aimed to interest primarily the large telegraph companies
in his machine, those companies which handled the transatlantic
t e l e g r a p h t r a f fi c i n p a r t i c u l a r .
I n f a c t w i t h s u c h m a c h i n e s t h e r a d i o t r a f fi c c o u l d h a v e b e e n
j u s t a s s e c u r e a s t h e c a b l e t r a f fi c .
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Fig. 8 "Electrocrypto B-18" by A.G. Damm
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II. The First Machines
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When in 1921 the capital of A.B. Cryptograph was ex
hausted, none of the stpckholders would or could make
f u r t h e r f u n d s a v a i l a b l e . H o w e v e r, a t t h i s p o i n t t h e
d i r e c t o r o f t h e c o m p a n y s u c c e e d e d i n i n t e r e s t i n g D r.
Emanuel Nobel in the A.B. Cryptograph and its possibili
ties. Because of the Revolution the Nobels had lost
their holdings in Russia: a large mechanical factory
a n d t h e l a r g e s t R u s s i a n O i l fi r m , t h e " N o b e l B r o t h e r s
Oil Production Company".
W i t h r e g a r d t o t h e A . B . C r y p t o g r a p h D r. N o b e l c o n s u l t e d
his colleague and close friend Karl Wilhelm Hagelin, my
f a t h e r, a n d t h e y c a m e t o t h e c o n c l u s i o n t h a t t h e p o s s e s
sion of good cipher machines for written communications
c o u l d p l a y a d e c i s i v e r o l e i n o f t e n d i f fi c u l t b u s i n e s s
affairs. Based on that conclusion Nobel himself decided
to invest new funds in the A.B. Cryptograph, and my
father also took a small part in the company. He was
technically interested as he was an engineer himself.
Since the director of the A.B. Cryptograph, Arvid Gerhard
Damm, had a rather obstinate personality, Nobel and K.W.
Hagelin needed a trustworthy person to monitor his
activities. Because I was then living in Stockholm where
I had opened my small engineering office, Mr. Nobel asked
me to watch over A.B. Cryptograph.
When I joined the company, Damm's interests in cipher
m a c h i n e s w e r e c o n c e n t r a t e d i n t h e fi e l d o f r a d i o t e l e
g r a p h y. W h e n I fi r s t a p p e a r e d a t t h e c o m p a n y o f fi c e s a
complete layout was on display: a typewriter for the
input of text, a cipher machine, and a typewriter equip
ped with electromagnets for the output of enciphered
or deciphered text. Damm had succeeded in arousing the
interest of the major radio telegraph companies in
his machine and prototypes were to be built by one of
t h e s e c o m p a n i e s i n P a r i s . A f t e r I j o i n e d t h e fi r m D a m m
moved to Paris, and I had to look after the business
s i d e o f t h e fi r m a n d i t s t e c h n i c a l d e v e l o p m e n t m o r e t h a n
I had originally expected.
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In the end Damm succeeded in winning the "big four" to
h i s p r o j e c t : M a r c o n i , Te l e f u n k e n , T S F a n d We s t e r n U n i o n .
T h e y fi n a n c e d t h e c o n s t r u c t i o n o f f o u r p r o t o t y p e s . B u t
these did not appear to be reliable enough and were too
s l o w, s o t h e p r o j e c t f a i l e d .
In the meantime, however, Damm had developed a system
w i t h s o - c a l l e d s i m p l i fi e d r o t o r s , a n d s o m e p r o t o t y p e s
o f t h e s e w e r e b u i l t f o r w i r e l e s s t r a f fi c . T h e m a c h i n e s
consisted of three units: The keyboard, the ciphering
*
portion with motor drive, and the output unit -- either
an electromechanical tape punch (a Creed Morse code punch),
which was equipped with a magnetic control or an electric
t y p e w r i t e r.
Fig. 8 shows under (a) the ciphering unit, under (b) the
tape punching machine, the keyboard and the ciphering
u n i t , a n d u n d e r ( c ) a n e l e c t r i c t y p e w r i t e r, k e y b o a r d
and ciphering unit. This machine was Damm's Electrocrypto B-18.
T h e p r i n c i p l e o f t h e s i m p l i fi e d r o t o r l a t e r b e c a m e t h e
salvation of the faltering business. But this came only
after Damm's death in 1927.
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I n 1 9 2 5 I w a s a b l e t o m a k e m y fi r s t p o s i t i v e c o n t r i b u t i o n t o
the A.B. Cryptograph, and this proved to be of decisive im
p o r t a n c e f o r t h e f u t u r e o f t h e c o m p a n y. I h a p p e n e d t o h e a r
that the Swedish General Staff had received an "ENIGMA" ma
c h i n e f o r s t u d y a n d I r u s h e d t o v i s i t t h e o f fi c e r c o n c e r n e d
w i t h t h i s m a t t e r. I e x p l a i n e d t o h i m t h a t t h e A . B . C r y p t o g r a p h
a l r e a d y h a d t e n y e a r s o f e x p e r i e n c e i n t h e fi e l d o f c i p h e r
m a c h i n e s a n d t h a t I w o u l d b e a b l e t o o ff e r s o m e t h i n g p o s s i b l y
superior to the "ENIGMA".
The General Staff wanted our machine to be the same size as the
ENIGMA and to operate in the same way. Time was short and I had
only six months to produce the new machine. At the time we had
only Damm's earlier constructions on hand, and they did not
fi l l o u r n e e d s . N e v e r t h e l e s s I p r o m i s e d t o d e l i v e r. I n t h o s e
days I had no experience whatoever about cryptography but I
had a certain talent for tinkering: I believed I would be able
to build a comparatively compact machine on the basis of Damm's
" s i m p l i fi e d r o t o r s " . T h i s d e s i g n m a d e u s e o f a 5 x 5 g r i d ,
w h o s e p r i n c i p l e i s s h o w n i n a s i m p l i fi e d d i a g r a m i n F i g . 9 .
& & 8 & 0
£_&_&_&
£ _ & &_&_&
& & & 0 &
X
£ _ & M-M-£
Fig. 9 5x5 Matrix
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To build the first model of the machine Emanuel Nobel allowed
me the sum of 500 kronor, about $ 134.— (!) I succeeded in
producing a prototype within the size limitations and in the
time authorized, a somewhat primitive model but still adequate
for the evaluation. This machine had a keyboard, 2 rotors
whose stepping was controlled by two separate pairs of pinwheels (keying-wheels) with different divisions on their
p e r i p h e r y, a n d w i t h a d i s p l a y o f 2 5 e l e c t r i c l a m p s w h i c h
served to indicate the output letters for encipherment or
decipherment (Fig. 10). This prototype was analyzed by a
mathematician, and approved instead of the ENIGMA for use by
the General Staff.
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Fig. 10 B.C.W. Hagelin's B-21 (Prototype)
Because Damm used a 5 x 5 grid, it was necessary to eliminate ^
one letter of low frequency or to use the same signal for two
letters, e.g. for i and j.
The keyboard was connected with two groups of 5 contacts each.
By operating a key, one contact was closed in each of the two
groups, forming one of the 25 possible combinations. After the
closing of two circuits through the two rotors, and a further
circuit through a relay system, one of the 25 electric lamps
l i g h t e d u p a n d i n d i c a t e d t h e r e s u l t i n g l e t t e r. T h e r e l a y s y s t e m
was necessary because at that time there were as yet no devices
l i k e m o d e r n d i o d e s , w h i c h w o u l d h a v e s i m p l i fi e d t h e c o n s t r u c t i o n
c o n s i d e r a b l y. I n o r d e r t o b e a b l e t o v a r y t h e e n c i p h e r e d a l p h a
b e t s , s o - c a l l e d m o d i fi c a t o r s w e r e a d d e d i n s e r i e s w i t h t h e
rotors, i.e., interchangeable leads which could be plugged
in as desired. This provided 51 = 12 0 combinations for each
group and for both groups together yielded 14,400 possibilities.
It should be noted that after the Second World War I developed
a new modificator system which could generate all 251 - 1.55
25
^
x 10 possibilities, but at that time this machine had been
superseded by my C-Type machine.
-18-
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The designation "pin-wheel" mentioned above needs to be ex
plained since the pin-wheel came to be used later in many
other machines. It is a disk which carries on its periphery
a number of axial holes or slots in which pins are located.
These pins are movable and are so arranged that they can pro
trude on one side or the other of the pin wheel. One side of
the wheel is the "active" side, i.e., pins which protrude
on this side exert a controlling effect. The pin-wheels are
stepped with each operation, each wheel moving one pin position
during each operation. The, cyclic length of the wheels have
no common factors. Thus as several wheels work together, a
very long period for the key is obtained.
The prototype had four pin-wheels, with cyclic length of
17, 19, 21, and 23, which yielded a combined keying cyclic
CS
length of about 1.5 x 10 , or 1'500'000 operations.
By using different combinations of pin settings theoretically
0
2 1x 72 „ 1 9 x 021
2
x 23 = 2 o r a p p r o x i m a t e l y 1 0 d i f f e r e n t
period characteristics could be obtained. This meant that an
enormously large number of variations was possible.
The prototype of the machine (Fig. 10), which was given the
name B-21, is still in the possession of the CRYPTO AG.
O
O
Fig. 11 B-21 with solenoid Magnets (Series)
-19-
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I
Fig. 11 shows the final model, in appearance quite similar to
the "ENIGMA". It used a power supply of 110 or 220 volts for
a solenoid magnet which operated the stepping of the rotors.
For the lamp display a flashlight battery was utilized.
For the convenient use of this machine in central offices
with extensive operations, it was connected to a Remington
electric typewriter instead of the lamp display (Fig. 12).
Typewriter keys were activated by small electromagnets and
the lamp display was shut off.
I
* I
Fig. 12 B-21 with electric Typewriter
-20-
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III. The B-211 Machine
After Emanuel Nobel died in 1932 his heirs did not want
to make any more funds available for A.B. Cryptograph.
I myself had been working without pay because the firm's
i n c o m e h a d b e e n v e r y m e a g e r. I n s p i t e o f t h e l i m i t e d
possibilities I was able to make several trips to other
countries where I found buyers for the B-21. The decisive
s u c c e s s , h o w e v e r, c a m e f r o m t h e i n t e r e s t o f t h e F r e n c h
Army in our machine. Before the machines could be sold
t w o r e q u i r e m e n t s h a d t o b e f u l fi l l e d : t h e m a c h i n e h a d
to be able to print the text and should also be portable.
This called for the implementation of an electromechanical
drive. I succeeded in solving this problem in a short time
by replacing the lamp display with a special type wheel
printing mechanism, (Fig. 13), which I had designed.
O
Fig, 13 B.C.W. Hagelin's B-211
-21-
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I
Since the machine, which we called the B-211, was to be built
in France, we got as manufacturer the French subsidiary
o f t h e Te l e f o n - A B L . M . E r i c s s o n l o c a t e d i n C o l o m b e s j u s t
northwest of Paris.
The B-211 was provided with shift keys like those on a type
w r i t e r. D u r i n g e n c i p h e r m e n t o n l y l e t t e r s w e r e p r i n t e d , b u t
during decipherment letters, numbers and symbols were printed.
The machine also had a crank so it could be operated by hand
in case the electric power failed. For the ciphering circuits
a fl a s h l i g h t b a t t e r y w a s u s e d , a s i n t h e B - 2 1 m a c h i n e .
I
Before the outbreak of World War II about 500 B-211 machines
w e r e b u i l t a n d d e l i v e r e d . I t w a s t h r o u g h t h e fi n a n c i a l s u p p o r t
o f m y f a t h e r, w h o l i v e d i n P a r i s a t t h e t i m e , t h a t t h i s b u s i
ness could be carried through. It would not have been possi
ble without his encouragement and funds, and it was not easy
for him.
When the war broke out, my father at the last moment succeeded
i n t r a n s f e r r i n g t h e p r o fi t s f r o m F r a n c e t o S w e d e n . T h e a m o u n t
was large enough to pay for his expenses and install and equip
a modern workshop. It was our first workshop since the founding
of the A.B. Cryptograph in 1915. The shop was dedicated at
New Year's eve of 1940 by the heirs of the A.B. Cryptograph
a n d w a s r e n a m e d t h e " A . B . I n g e n i o r s fi r m a n C r y p t o t e k n i k " .
It may be mentioned that the French army after the War bought
an additional 100 B-211 machines.
I a l s o m i g h t m e n t i o n t h a t I w a s o b l i g e d b e f o r e t h e Wa r t o s e l l
"two cipher machines" to the Russian Trade Commission in Stock
holm (according to the purchase order). I sold them two B-211
machines which we had in stock in Stockholm.
*
«
The machines were copied in Russia and used during World War II.
Th e y were provided with a 5 x 6 grid. The Cyrillic alphabe t h a d
more than 30 letters but a few of them occurred very seldom,
a n d c o u l d b e o m i t t e d . A l s o t h e m o d i fi c a t o r s w e r e p l u g g e d i n
outside of the machine, probably under locked cover so that
the operator would not know which inner settings were in use
at any given time (Fig. 14).
31
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Fig. m Copied B-211 for Cyrillic Alphabet
)
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IV. The C-Machines
Quite soon after the beginning of our business relation
ship with the French "Deuxieme Bureau" I was asked in
d se v g
e oi °o?d al u c ko mwpoaucl td "hpaovcek eit ", Ic i ph h
aa
cd
h vi n e
t h a t pnrriinnt^eTd^. A
ae
d r am
lre
a few years before received from two Swedes an order to
design a com changing machine. After I had built a
functioning prototype, I got the idea that it should be
possible to insert any amount in coins, to enter the
i n v o i c e a m o u n t b y a k e y, a n d fi n a l l y t o g e t b a c k t h e
change. This machine was equipped with a unique calcu
lating mechanism but it was never built because we had
not been reimbursed for our development effort. We agreed
to cancel the debt and retained the rights for our designs.
T r y i n g t o fi n d a s o l u t i o n f o r t h e " p o c k e t d e v i c e " f o r t h e
French, I got the idea to incorporate the calculating
mechanism for the money changer into such a device. The
revolutionary invention" (in the opinion of distinguis
hed cryptologists) consisted in a pure association of
ideas that were transferred from one to another completelv
different
fi e l d
of
application.
'Purely
The calculating mechanism of the money changer consisted
of a drum with displaceable axial bars around its circum
f e r e n c e w h i c h c o u l d b e a ff e c t e d b y o p e r a t i n g t h e k e y s
T h o s e b a r s w h i c h w e r e a ff e c t e d i n a n o p e r a t i o n w e r e d i s - ~
placed to the left as the drum turned. A type wheel mes
hing with the drum was turned exactly the same number of
steps as the number of bars moved to the left. I replaced
the keys of the money changer with pin-wheels, and the
type wheel carried letters now instead of numbers. In
this way I obtained a cipher mAchine. In order to estimate
t h e d i m e n s i o n s d e s i r e d , I c u t o u t a w o o d e n b l o c k t o fi t
s n u g l y i n t o t h e p o c k e t o f a j a c k e t . F o r t h e fi r s t m o d e l s
I used a drum with 25 bars and|five pin-wheels of the same
construction as those in the B-21. These wheels were pro
vided with pins around their circumferences, which could
be placed axially in two different positions, either
"active" or "inactive". "Active" pins worked upon the
drum by means of a control arm.
-24-
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r>
^
Fig, 15 B.C.W. Hagelin's C-35
%
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The bars of the drum are provided with cams, i.e., raised
a r e a s o n t h e i r e d g e s , o f s u c h a d e s i g n t h a t t h e fi r s t b a r
w o u l d b e m o v e d b y t h e c o n t r o l a r m o f t h e fi r s t p i n - w h e e l ,
the next two bars by the second wheel, the next four by the
third, the next eight by the fourth, and the remaining ten
b a r s fi n a l l y b y t h e fi f t h w h e e l ( F i g . 1 5 ) .
Depending on the number and the arrangement of active pins in
the pinwheel in question the control levers will be pushed
against the periphery of the drum, or remain in their inactive
positions. When the drum is revolved during an operation the
active levers push the corresponding bars (from 0 up to 25
bars) to the left and so engage the gearwheel connected to
the typewheel. The typewheel is therefore displaced a number
of steps equal to the number of the active bars. The drum thus
acts like a gearwheel with a variable number of teeth. As the
number of pin divisions on the pinwheels has not any common
d e n o m i n a t o r, t h e l e n g t h o f t h e k e y p e r i o d , i . e . , t h e n u m b e r
of operations which are needed before the pinwheels return
to their common starting position, is very long.
F o r t h e fi r s t m a c h i n e s t h e d i v i s i o n s , o r c y c l i c w h e e l l e n g t h s
selected were 17, 19, 21, 23 and 25, which resulted in a period
length of 3'900'225 operations, a length which until then had
not been achieved in any mechanical ciphering machine.
M o r e o v e r, s i n c e o n e c o u l d s e t a l l t h e p i n s t h e o r e t i c a l l y i n
a b o u t 1 029 d i f f e r e n t c o m b i n a t i o n s , t h e n u m b e r o f p o s s i b l e
variations was so high that these machines are fully adequate
f o r c e r t a i n p u r p o s e s e v e n t o d a y.
Later I made various changes in direct response to the steady
p r o g r e s s i n c r y p t a n a l y s i s , w h i c h i n c l u d e d t h e s i g n i fi c a n t w o r k
of the Swedish cryptologist Y. Gylden. The main improvement
c o n s i s t e d o f i n c r e a s i n g t h e n u m b e r o f p i n w h e e l s f r o m fi v e
to six, and to introducing rearrangeable lugs on the drumb a r s i n s t e a d o f fi x e d c a m s .
When the machine began to be produced in larger quantities, a
bottom plate and a protective cover were added. The bottom'
plate was formed so that the machine could be used in the
fi e l d s t r a p p e d o v e r t h e k n e e o f t h e o p e r a t o r. I f n e c e s s a r y
the operator could even march with the machine strapped to
his thigh. This new type of apparatus was given the designa
t i o n C w i t h o n e l e t t e r a n d a n u m e r a l s u f fi x w h i c h o r i g i n a l l y
d e s i g n a t e d t h e m o d e l y e a r b u t a f t e r 1 9 5 2 d e fi n e d t h e s p e c i fi c
model of the machine: e.g., CX-52.
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The opportunity to establish a modern workshop with the royal
ties from our French sales occurred just before the outbreak of
World War II. It thus became possible for us to make and sell a
c o n s i d e r a b l e n u m b e r o f m a c h i n e s d u r i n g t h a t Wa r. O u r fi r s t l a r g e
customer were the Swedish defence forces with whom I had main
tained connections since 1925. From France we received an order
for over 5000 machines, which were to be manufactured by Ericsson
at Colombes, but this order could not be completed.
To p r o m o t e t h e C M a c h i n e I m a d e s e v e r a l t r i p s , fi r s t w i t h i n
Europe, but in 1937 I went again to the USA where the wish was
expressed to have an electrically powered machine with a key
board. In the summer of 1939 I took a prototype of the so-called
B C M a c h i n e t o Wa s h i n g t o n . U n f o r t u n a t e l y t h e c o n s t r u c t i o n n e e d e d
improvement and I returned to Sweden the same autumn after the
r % outbreak of War with matters still unsettled.
J
I made another trip to the USA at the beginning of March 1940
o n m y o w n i n i t i a t i v e w i t h o u t a n y r e q u e s t f r o m Wa s h i n g t o n . I
was able to leave on the last ship from Europe at Genoa on
May 10, 1940 with two machines in my luggage before the
I t a l i a n s e n t e r e d W o r l d Wa r I I . T h i s t r i p w a s t o l e a d t o t h e
largest sale of C Machines ever made.
The American business began with an initial order for 50 ma
chines which were shipped airfreight from Sweden to Washington.
A fte r e xte n si ve te sti n g th e ma ch i n e w a s a cce p te d . Th e Am e r i c a n s
selected it for tactical use, as they did not have any comparable
machine at that time. The C Machine, designated in America as the
M-209, was manufactured by the Corona plant of the L.C. Smith
t y p e w r i t e r c o m p a n y, w i t h a d a i l y o u t p u t o f u p t o 5 0 0 u n i t s .
I remained in America during the war and had a small shop in
my home for servicing BC Machines which were used by an
A m e r i c a n o r g a n i z a t i o n d u r i n g t h e w a r.
When it became possible for me to return to Sweden in 1944,
more than 50'000 machines had been built. By the end of the
war over 140'000 units were made in America.
During my four year stay in the States the workshop in Stockholm
was kept busy with orders from several foreign countries. One
delivery went by an extraordinary way to Japan. The machines were
smuggled out by the Japanese military attache in a night boat
passage and picked up by a U-Boat off the coast of Sweden. But
very few machines reached their intended destination in Japan.
It seems worth mentioning that the German authorities, who years
before the war showed no interest in the demonstrated C Machine,
began, toward the end of the war, in the Wanderer works at Chem
nitz to manufacture a copy of the BC Machine for their own use
because the "ENIGMA" machine had been broken by the British
(Fig. 18).
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Fig. 16 B.C.W. Hagelin's BC-543
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r>
)
Fig. 17 USA-version of the C-36: M-209
,
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Fig. 18 Ml (german copy of the BC-543)
-30-
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When the third Reich collapsed they had only been able to manu
facture about 7 00 machines. It is even more interesting to note
that in the 1950's postwar variation of the C Machine was built
in Germany under licence. About 10'000 machines are said to have
been produced. France also obtained the manufacturing rights for
the C Machine for the francophone community.
It should be stressed that the C Machine was planned for tactical
purposes, i.e., for use at the front. When, because of its simp
l i c i t y a n d p o r t a b i l i t y, t h e m a c h i n e a l s o p r o v e d t o b e i n t e r e s t i n g
for use in the diplomatic service, improvements were needed to
a t t a i n a h i g h e r d e g r e e o f s e c u r i t y.
•
I fi r s t g o t t h e i d e a o f m o d i f y i n g t h e m a c h i n e s o t h a t t h e r o t a
t i o n o f t h e p i n - w h e e l s w o u l d b e i r r e g u l a r l y. O t h e r i m p r o v e m e n t s
were introduced as well. The new type brought no large changes
in the basic structure of the original C Machine. This new ma
c h i n e w a s fi r s t g i v e n t h e d e s i g n a t i o n C X - 5 2 b u t l a t e r, a f t e r
different pin-wheel movement variations were made, new model
numbers were used (Fig. 19
r*
^i
Fig. 19 The C(X)-52
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Before going into the details of the various improvements, it
is important to emphasize that the requirements of our custo
mers led in two opposite directions. One group required very
long key periods, while the other wanted a movement of the
pin-wheels that was as irregular as possible. It required great
mathematical competence to compile keys which would assure that
s u f fi c i e n t l y l o n g p e r i o d s w e r e o b t a i n e d . I n o r d e r t o s a t i s f y
our customer we also developed hybrid systems where usually
o n e p i n - w h e e l w a s s t e p p e d r e g u l a r l y a n d t h e o t h e r s i r r e g u l a r l y.
The further development of the C Machine, which even today,
in the age of electronics, is being used, can now be followed
in some detail:
a) The number of pin-wheels was increased quite early to
s i x . I n s t e a d o f t h e o r i g i n a l fi v e w h e e l s w i t h d i v i s i o n s
of 17, 19, 21, 23 and 25, 12 pin-wheels became available
with divisions of 25, 26, 29, 31, 34, 37, 38, 41, 42,
43, 46 and 47, of which six were to be used at one time,
preferably those with no common factors. The wheels were
inserted easily without using a tool.
b) The number of slide-bars was increased to 32. In place
of the fixed cams on the bars which caused the type-wheel
to turn, movable lugs were installed on each bar so that
the movement arrangement for the type wheel could be
changed as desired. For other ways of using the machine,
s o m e b a r s w i t h fi x e d c a m s v / h i c h c o n t r o l i r r e g u l a r f o r
ward movement of the key wheels were manufactured.
c ) E v e n i n t h e v e r y fi r s t C M a c h i n e s r e c i p r o c a l a l p h a b e t s
were utilized. With a letter sequence on the type-wheel
running in the opposite direction to that on the indi
cating disk, the same machines could be used both for
e n c i p h e r i n g a n d d e c i p h e r i n g w i t h o u t a n y m o d i fi c a t i o n s .
In later models a second type-wheel was introduced, which
was permanently connected to the indicating disk, and
which printed the same letters which were set with the
indicating disk. They were called "primary" and secondary"
type-wheels, where the primary type-wheel is connected to
the indicating disk. There are also available indicating
disks and type-wheels, where the letters can be rearranged
a t w i l l , a n d w i t h o u t r e m o v i n g t h e m f r o m t h e a s s e m b l y.
One model printed the plaintext in the characters of a
non-European language (e.g. Arabic) and the ciphertext
in Latin letters, and one text (Arabic) read from right
to left and the other text from left to right. This
arrangement was indispensable for Arab countries using
the international telegraph service.
-32-
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)
'j
;
c
Fig. 20 CX-52 (disassembled)
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d) Between the indicating disk with the primary type-wheel
and the secondary type wheel was a disconnectable clutch
It could either retain the chosen relative positions
between the primary and secondary type-wheels during a
series of messages or change each time at the start of
the next letter in the text.
e) For the easy setting of the pins on the pin-wheels a
special tool was provided. This tool set in a single
operation all the pins in one wheel.
f) A special device which was developed at the request of ^
one customer was the mechanization of the "one-time pad"
system which had been a slow hand procedure.
N e a r t h e e n d o f W o r l d Wa r I t h e A m e r i c a n Ve r n a m m a d e t h e
fi r s t a t t e m p t t o m e c h a n i z e t h i s s y s t e m f o r t e l e g r a p h u s e .
He used for the key-tapes punched paper tapes with random
sequences of teleprinter signals. The characters of the
plaintext in the standard CCITT No. 2 code were combined
by means of relays with the key-tapes according to the
system of the "exclusive-or" associating plus and minus
in the following way:
+ and + results in +,
+ and - results in -,
- and + results in -,
- and - results in +.
A f t e r Wo r l d Wa r I I w e l e a r n e d t h a t s p e c i a l d e v i c e s h a d
b e e n b u i l t t o g e n e r a t e s u c h t a p e s . C o n s e q u e n t l y o u r fi r m
also developed special electronic random generators for
producing key-tapes.
I n P a r t V I b e l o w, a s a c u r i o s i t y, I h a v e d e s c r i b e d t w o
of my designs for the automatic production of "one-time
pads".
g) While the pre-war C Machine was supplemented with the key
board BC-machine, for the modern C Machine we developed
a separate attachment, named B-52 ... B-62, which was
provided with keyboard and electrical operation. In
smaller message centers the C Machine alone was suffi
cient, while in large ones the C Machine was mounted on
this device (Fig. 21).
■
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O
Fig. 21 A: B-62
B: BC-62
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h) The PEB Machine provided easier operation for telegraphic
traffic. The device consisted of a tape punch and a tape
reader and could be connected by a cable with a BC Ma
chine. During encipherment a punched tape with ciphertext
was made on the PEB (possibly with the address in plain
language placed at the beginning) and was dispatched
directly over the punched tape transmitter of the tele
printer station. At the receiving end the cipher was
punched on the tape which could then be deciphered
automatically with the PEB (Fig. 22).
Fig. 22 Left: PEB-61
Right: BC-621
%
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^
$
The various improvements caused the C Machine to outgrow its
pocket-size format. Now I wished to build a "pocket machine"
in the true sense of the word. I was able to introduce a
model which, because of its small size, could not print but
nonetheless allowed an easy read-off of the text letter by
l e t t e r. T h e c i p h e r m e c h a n i s m w a s q u i t e d i f f e r e n t f r o m t h a t
in the C Machine but the device was fully compatible with a
contemporary variation of the C Machine, which worked with
regular stepping of the pin-wheels.
The French gendarmerie urged us to build this pocket machine
and assured us of an order of at least 4000 units. Although
this quantity was not actually reached, lots of these machines
were sold, which came on the market under the designation
CD-55 and CD-57 (Fig. 23). About 12'000 have been delivered.
The input and output elements of the device consist of a ring
inscribed with an alphabet and rotatable disk inside the ring.
A levergrip pressed by the left thumb causes the displacement
of the alphabet disk in each operation. With the right hand
t h e r e s u l t i n g t e x t c a n b e c o p i e d l e t t e r b y l e t t e r. I f t h e
letters are not in sequence the encipherment must be done
from the ring to the disk and the decipherment from the disk
to the ring. For convenience users normally use reciprocal
alphabets and then can go from the fixed ring to the movable
disk for the output. Even these machines can be equipped with
a k e y t a p e r e a d e r.
<r»
n
-37-
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^
Fig. 23 CD-57, closed and disassembled
-38-
/
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^
#
V' The Telecrypto Machines
llllllli ** mrti0ned in the Introduction, I settled in
Z i t l e r l ainventor
n d " h e r eDr.* Edgar
w o r k e dGretener
f o r a s on
h o r tthet i mdevelopment
e w i t h t h e of
Swiss
t e"l emp er isnstaegr e sT.° "T^h e^sPe ^ i" no gn - l ai nned mdaecchiipnhe es r" i nwge r eo f
Dr G
t rrl et Lt et n* e ^r,^ afncdu et h E
e TlKi n et .e l O
ep
u r i nc toeorp, e rdaet si oi ng n deidd bn yo t
u s e w il tthn yaalili nssttaannd^a r\dd et ce^l e pt or i nbt euri sl d. D
mr.y G
ow
r ent e m
n earc' h si n e f o r
machrne is no longer in production. My preliminary work
Stockhor"^,16
WaS done
™y workshop
in
Stockholm, but KaChine
the manufacture
tookin place
at CRYPTO
AC
in^ug where some improvements were added to tnf original
T v P e ^ - S S t ! h b U i l t U n d e r m y E r e c t i o n : Ty p e T- 5 2 a n d
JJ\l Sf: B°th Were ^stalled between the teleprinter
t h"ihl ee ot ev leer P tr hi net elri n p
r snol yn nceilp^hoer kr teedx t
o n l yv w i t h pn l?a' iSn?t e xt ht 3w
eeo
the C
r r MMachine
n S ^ t t e ^ drum
B ° t h and
t y p Ssix
S U
S S d f o r t The
h e i r T-55
" k e y -model
g e n e r awas
tor"
the
pin-wheels.
also equipped with two tape readers, one for the text
tape and the other for a random key-tape. It was possible
key-rape! " """ **" ^"generator or with the^andom
V
m
1953 1954. It worked w
i t h sProduced
i x fi x e d pini n -series
w h e e l sin a Zug
nd
inei95352-ma954neT/Fi9\'4)
WaS
thfc^rMacnine"
^"^
"*-
«-
UdpS'o?-
The T-55 was designed in 1955 - 1956. It used six inter
changeable pin-wheels and a drum with 22 slide-bars like
the system in the C-52 series. The keying sequence was
g e n e r a t e d m b o t h t y p e s m e c h a n i c a l l y, t h e i n f o r m a t i o n
processing electrically by relays.
ls"t^ehpe i nT _w" h iecahc he atcehl e t9erlaepg h
r a pshi g ns iagl n ar e
l swual tse dp r forcoems s ead f ud ni rcetci tol vn and passed forward. The keying signals produced were Y
p a s s e d i n t o t h e fi v e k e y i n g s i g n a l r e l a y s , c o m b i n e d w i t h
the incoming telegraph signals according to the "excl
usive'
to
+■ " S e n d " 1 ' " ' ' *S
3 e" n' 3d - 3, 6R" e
1 c e° iU
t
;
,
T
h
S
T
"
5
2
C
O
u
l
d
b
e
^
t
b
y
h
a
n
d
v e " , o r " P u n c h e d Ta p e O p r a t i o n " .
-39-
3E720
Fig. 24 Telecrypto T-52 with and without hood
-40-
3E720
$
I n c o n t r a s t t o t h e T- 5 2 , i n t h e T- 5 5 ( F i g . 2 5 ) t h e k e y i n g
signals were not stored but were produced continuously as
fi v e k e y i n g s i g n a l e l e m e n t s d u r i n g o n e c y c l e o f t h e m a c h i n e
and combined according to the "exclusive-or" rule with each
binary element of the telegraph signal. Therefore the slidebar drum had to run synchronously with the teleprinter signal,
a n d c o n s e q u e n t l y t h e fi v e k e y i n g i n f o r m a t i o n e l e m e n t s a l w a y s
coincide with the text elements.
In addition the T-55 was equipped with a tape reader by means
of which a superencipherment, i.e., mechanical keying generator
plus random key-tape was obtained. As an important improvement
o v e r t h e T- 5 2 M a c h i n e t h e T- 5 5 o ff e r e d a u t o m a t i c d i r e c t i o n
reversing.
A n o t h e r i m p o r t a n t f e a t u r e o f t h e T- 5 5 w a s t h e r e m o t e l o c k
f o r t h e a n s w e r - b a c k u n i t o f t h e t e l e p r i n t e r. W h e n t h e T- 5 5 w a s
not in use it remained on "plain language operation". Should
t h i s m a c h i n e b e c a l l e d , t h e n a f t e r o p e r a t i o n t h e W RY- K e y a t
t h e t r a n s m i t t i n g t e l e p r i n t e r a " C a l l " b u t t o n a t t h e T- 5 5 w a s
pushed which locked the sending loop of the remote station.
By this action the incoming transmission could not be jammed
by an answer-back sent during the transmission.
Later the tape could be deciphered in a local loop.
The answer-back lock was released automatically when the
lines were disconnected, and the station was then ready to
operate in both ways again.
I
To produce the key-tapes for these machines we constructed a
t h r e e - p a r t a p p a r a t u s : a n e l e c t r o n i c r a n d o m n u m b e r g e n e r a t o r,
a punch, and a labeling machine. The punch, of American design,
could do up to 120 characters per second. It produced two
identical tapes at the same time, which were printed upon
a t r e g u l a r i n t e r v a l s w i t h c o n s e c u t i v e i d e n t i fi c a t i o n n u m b e r s
a c c o r d i n g t o c u s t o m e r s ' s p e c i fi c a t i o n s .
The use of random key-tapes became very popular. But after
some years the use of this system declined because of the
problems of supplying and distributing key tapes. Key tape
machines were then replaced by electronic telecrypto machines.
Both machines were single-shaft regenerators in terms of tele
graphic technique. They delivered error-free telegraphic im
pulses, which left no possibilities whatever for electronic
cryptanalysis by means of pulse analysis.
/'I
-41-
3E720
'•-,
Fig. 25 T-55, A: Office Version, B: Field Versi on
-42-
*
</,
3E720
VI. Miscellaneous Machines
Some machines are described which were built only as
prototypes or in small numbers.
1. An Autokey Machine of the C-Type
r. y
code
Customers have always looked for cipher systems which are
not only secure but also simple to operate. As an example
of such a system the autokey cipher will be described.
The correspondents utilizing this system used a list of
words to indicate the starting point in the keying
sequence. It soon appeared that this system was not
a b s o l u t e l y s e c u r e s i n c e " P r o b a b l e Wo r d s " c o u l d h e l p t o
analyze the ciphertext, i.e., to make decryption trials
in order to discover where such words or sentences are
located in the secret message. This system was thus
discarded.
But the idea to integrate the text into the keying se
quence was very attractive to me, and in 1948 I designed
a machine which was built only as a prototype. The basic
principle of this machine was to combine the text to be
enciphered with a classical cipher system in such a way
that the text component of the keying sequence would not
be vulnerable to analysis. The keying sequence of a
classical machine was thus changed into a pseudo-random
keying sequence. I use the expression pseudo-random since
^ the sequence of letters in plain language can not be
V considered completely randomly distributed. However,
from a practical viewpoint the combination of a
continuous keying sequence combined with this text to
be enciphered could in practice be called randomly
distributed.
For the classical cipher machine I used a normal pre-war
C Machine with five pin-wheels and a drum with 25 slideb a r s . T h i s m a c h i n e w a s m o d i fi e d s o t h a t i n p l a c e o f t h e
toothed wheel drive, a drive using a latch drive for the
regular movement of the pin-wheels was used. A drum
equipped with 26 slide-bars was placed in front of
the latches (Fig. 26).
Z*
-43-
3E720
Fig. 26 C-36 with Autokey (Prototype)
This auxiliary drum was connected via gears to the indicating
disk, so that for each change of the indicating disk a
corresponding auxiliary slide-bar came into active position
before the latches. The auxiliary slide-bars were provided
w i t h fi x e d l i f t e r s . A s a n e x a m p l e t h e l a t c h e s f o r p i n - w h e e l s
1 and 3 of one slide-bar could correspond to the letter A
of the setting disk and could be found in the input position.
They could then be brought into an active latch position by
a movement of the drum, so that in the succeeding operation
the pin-wheels 1 and 3 would be moved one step forward.
These slide-bars were interchangeable, so they could be set
i n t o 2 6 1 d i ff e r e n t s e q u e n c e s i n t h e i r d r u m .
!
-44-
*
3E720
The machine functioned as follows:
Before starting an encipherment the pin-wheels were set into
o rnns . o T
n it nh dei claetti tnegr dt ios kb ei n teon ci ti sp hienrpeudt
w a s^ h b rSoPu eg £h it £b y Pa^ ^ ti u
f ht e
he
rTth^J SlldS:bar °n the Miliary drum corresponding
ce
t h ef o l laocwtei dv,e wph iocsh i tt iuor nne. d Tt h ee ns ett h
r o tta toi o n^ ^o f ^ tvhae n m
a idn tdor u m
t i ne g
of the indicating disk/type wheel unit the same number of
steps determined by the pin arrangement on the pin-wheels and
the distribution on the main drum. The resulting cipher letter
was printed and the auxiliary drum directed against the latches
i n o r d e r t o a d v a n c e t h o s e p i n - w h e e l s a ff e c t e d b y t h e a c t i v e
w latches one step forward at the end of the operation.
In decipherment the active time for the movement of the latches
was shifted to the beginning phase of the operation. After
setting the cipher letter into the input position the turning
m o v e m e n t w a s p e r f o r m e d fi r s t , t h e n t h e r e a d j u s t m e n t o f t h e
pt yl p
a ei n twehxet e ll eut tnei tr,. a n d fi n a l l y t h e p r i n t i n g o f t h e d e c i p h e r e d
H o w e v e r, I r e l u c t a n t l y d i s c a r d e d t h i s d e v i c e b e c a u s e t r a n s m i s s i o n
errors and garbles causing the keying to get out of step could
l e a d t o c o n s i d e r a b l e d e l a y i n r e c o v e r i n g t h e m e s s a g e . To d a y
this objection is no longer valid since transmission technique,
either by wire, radio, or even via satellite, has been
improved immensely.
c
I regret that this simple and good machine came too early
and today has been outdated by its electronic successors.
i
2 . T h e C i p h e r i n g Te l e p r i n t e r i
I n 1 9 5 3 a n e x p e r i m e n t a l c i p h e r i n g t e l e p r i n t e r, Ty p e T M X , w a s
built.
i
It had four input possibilities: keyboard, text tape, key-tape
and incoming signals, and three outputs:
print-out, tape-punch and outgoing signals (Fig. 27)
I soon realized, however, that CRYPTO AG possessed neither the
fi n a n c i a l n o r t h e t e c h n i c a l m e a n s t o c o m p e t e w i t h s u c h a
m a c h i n e a g a i n s t t h e m a j o r t e l e p r i n t e r fi r m s . W e s t i l l h a v e
the prototype, but we dropped this large project and under
took something more suitable to our capabilities: the manu
facture of a telecrypto machine which could be connected
to normal teleprinters.
-45-
3E720
Fig. 27 Cipher Teletype TMX-53 (Prototype)
-46-
3E720
^
#
3. "One-Time Pad" Machine;
-oriolifroliiS
SS
of
^
^
^
M?"
of letters'on a typewriter g w*f f^^ *»^ sequences
method regular patterns dL n J" "^ that with the latter
unusable. Patterns developed which made such "pads"
In
each
operation
fhp
chaff
*-«
dXie
snart.
The second design was even more unique 8 x 5 fvno „hoai
used with each wheel coordinate t-t ■ • YP wheels were
= i-s.'sis.™p=r ="—~™
q^lncrof^O^tre^61 """^ a -rresponding^rn^ .'£
x edf I e\W! P^lnted on the paper, the balls were
could restart *** **<* ±nt° the Charaber' and the operation
f o r ^ ^ i T ^ r l o fl Y d i g i t s T * T s l ^ T ' l ? * " * "
or number tables could be produced (Fig' 28, ' "^ ^"^
-47-
3E720
Mischkammer
Typenrad
Fig. 28 Random Number Generator with Printer CBI-53,
A: Principle B: Unit
-48-
*
^
#
3E720
4■ Rotor Machines
Even when mechanical and electromechanical machines became
a u r a I t ? * T l m a ° h i n e Wa s S t i 11 — r o u n d e d b y a c e r t a i n
nn™"
p o w e r sT™
, a nth3t
d w SUCh
e d e c i Mchines
d e d t o b»ere
u i l d being
a " s u pused
e r " vby
e r s ithe
o n "great
rotors
with fixed
andtyPG
simple
In 1952
we
rotorsewith
TES*' wiring
°f tMS
hadmotion.
the same
weakness
begun the first attempts to produce a different machine
with special rotors. One feature in our development was the
• i n p u t , k t b 3 H , • W, h i l S ° n l y 2 6 C i r c u i t s a r e n e e d e d f o r t h e
circuit Ynf0au\an.t °UtPUt 'Prater), the rotors have 41
the rotorsf SUrPlUS WireS are lo0*ed back outside
so
that 26. x 151
could bybe the
obtained
(around
? v
so'that^e-V?^
be. choices
rearranged
use of
modif5 icators,
3
8
"
"
"
'
»
'
«
«
c
o
u
i
a
o
e
o
b
t
a
i
n
e
d
(
a
r
o
u
n
d
5
.
2
x
10
The nine rotors were such that the connections within each
rotor could easily be changed in 24i different ways. Further1 e rotors
could used
perform
every
desired
combination
of
movements
like those
in the
modern
C Machine.
The program
choice was enhanced greatly by the use of electrical switches
A complete block diagram is shown in Fig. 29. swircnes.
C^i tf hher f ^t a p°ef p
f cuK
er r°t0r Mchines "ere supplied together with
nch device PEH-61 (Fig. 30) to a French government agency. The inconceivably large number of 600
10 -—
v a r to
iations was theoretically possible with this machine. Due
t h e HX-63
t?t\°Pm
r ^ ° fthee l ePEH-61
c t r o n i c machines
m a c h i n evias
s , t hdiscontinued.
e m a n u f a c tWe
ure of
the
and
manufactured for another firm a sizeable number of high
speed printers and tape readers originally developed for
this
machine.
c
.
-49-
3E720
Modificator
Printing unit {?) Plain (^S
P = Primary
S = Secondary
26! Combinations
M
(1-26)
Keyboard
o—-1 K>
fi
W \Y7
o
CD
switch
on "PL"
1
PLAIN
1—
PE-61
1
Perforator
.15
per rotor
2^' pin settings
41! reconnections
Trans
TCode
, ducer
1
15! Combinations
I ( 27-41 ) |
Converter
.26
I
Tape head
Plain
DECIPHERING
Fig. 29 Blockdiagram of HX-63
-50-
i—i—i—i—i—i—i—r
Rotor drive unit
J I I I I I I L
Modificator
of Rotor drive unit
9! Control chains
M
selector
MM
r>
3E720
a
^
c
»
Fig. 30 A: Rotor-Hach.ne HX-63 B: Paper Tape Un1t PEH-61
-51-
3E720
5. The CDS-62 Machine
Since 195 5 I had the idea of improving the CD pocket machine
further by the addition of a multi-alphabetical attachment.
In 1 9 5 0 th e r e n o w n e d c r y p to l o g i s t Wi l l i a m F. Fr i e d m a n h a d
once suggested I redesign the C Machine in order to enhance
i t s a p p l i c a b i l i t y. T h i s w a s t o b e d o n e b y t h e u s e o f 1 6 d i f f e
rent types of wheels which would engage in an irregular manner
This suggestion unfortunately did not work in practice. I
used, however, a version of this suggestion as an improvement
for the CD-57 machine.
In Sweden I made a first attempt by mounting on the turnable
shaft of the CD machine a cylinder on which 32 alphabets were
i n s c r i b e d . T h e s e c o u l d b e r e a d o f f a g a i n s t a fi x e d r e f e r e n c e
alphabet. One could say that this was simply an improvement
o f A . G . D a m m ' s fi r s t m a c h i n e , b u t w i t h a v a s t l y l o n g e r p e r i o d
(Fig. 31).
I changed the design and introduced interchangeable cards
carrying random alphabets (Fig. 32) .
7
Fig. 31 CDS-62: CD-57 with multi-alphabet attachment
-52-
3E720
cardfwere^robtain^e U^ ~ if SeParate alphabet
s ^rrton6rreepertei?quenoe to the refereni -52^
engaged
with
the
a«*^^.£*£1Sl£iS£:
c
t,
-53-
fUllY
3E720
Fig. 32 CDS-78 (Sample Unit)
-54-
"i
3E720
Closing Observations
3as L " °f "retography and cryptanalysis up to now
Z
LV ^ " l y. c oduring
n c e r n e dthew i last
t h mfive
a n u acenturies.
l s y s t e m s Although
w h i c h w ecipher
re
developed
lized field. It is equally obvious that the results of such
efforts are not published.
Each nation has to look out for its own security and does not
want to disclose any useful data to its adverseries
SS«2S=HSwj£~&
errors can simply not be eliminated. On the other handle
cryptanalyst today still has the chance of success through
his own intuition as he depends on the "probable word" i e
on stereotyped, often used expressions. Direct betravai or
/ unintentional indiscretion naturally do not belong to the
statisticafm^rr113^315- Th±S art dePends mainly on
tition* ^ r S' "hiCh aUows the recognition of repel l To t k 0 e f y i „ h g O S p e n r i o a d s ! n e S e t t i " 9 S " ^ " ^ «■" » * - r -
0
-55-
3E720
For this reason secure cipher communication requires not only
good equipment but also cryptologically trained personnel to
prepare the operating instructions for the machine, and very
t r u s t w o r t h y, w e l l t r a i n e d o p e r a t o r s w h o s t r i c t l y o b s e r v e
these instructions.
Because the C Machines have been sold in more than 5 0 coun
tries and are still being sold, the characteristic components
of these machines can be described in more detail. These parts
are as follows:
1. Setting disk or keyboard plus type wheels. When the
alphabet consists of 26 letters, these letters can be
arranged in 261 or about 4.3 x 1026 different sequences.
Moreover the indicating disk can be put into 26 diffe
rent positions relative to the type-wheel. There is also
a mechanism which allows this relative position to
change between the primary and secondary type wheels
co n tinuously during the processing of a message.
2. 32 slide-bars in the drum. Here 6 x 10 possible arran
gements of the lugs are available when all steps from
0 to 25, i.e., 26 steps, are included. These can be
permuted in 720 different ways. Special cams on the
drum bars can also be used to effect the movement of
the pin-wheels. These particular slide-bars are equip
ped with cams which work as teeth.
There are 4 possibilities of action by such teeth:
a) The tooth moves the associated pin-wheel when
the slide-bar has moved into active position.
b) The tooth moves the wheel when the slide-bar has
remained in inactive position.
c) The tooth moves the wheel no matter what position
the slide-bar is in.
d) The tooth does not move the wheel no matter what
the position of the slide-bar (see more below on
the performance of the CX and CXM). The possible
actions just described make 4 = 4096 possibilities
for one slide-bar or (4 ) = about 4 x 10
possibilities for the 32 slide-bars.
56-
?
0
,v
3E720
Pin-wheels. Here we have the largest number of possi
ble variations. There are 12 different pin-wheels to
choose from, and 6 wheels are used at one time in the
machine. The 12 different wheels, used 6 at a time,
make 663,280 different combinations, giving period
8
9
lengths between 10 and 2.7 x 10 . The number of
starting positions for the pin-wheels is the same as
t h e n u m b e r o f d i ff e r e n t c o m b i n a t i o n s , b u t t h e n u m b e r o f
possible different pin combinations reaches astronomi
cal numbers. Assuming half of the pins on each wheel
are active, which has been found to be most secure,
we get for example with the wheels 29, 31, 37, 41, 4 3
and 47 about 10 different pin combinations.
The C Machines, as already mentioned, were originally
designed for tactical use but gradually began to be
used in the diplomatic services. Every cipher service
has to set its own rules; nevertheless the numbers
g i v e n a b o v e s h o w i n g t h e a b u n d a n c e o f d i ff e r e n t p o s s i
bilities for setting the machine may be of general
interest.
There are three main varieties of the C Machine:
c
The normal C Machine (as well as the CD-57) when using
regular movement of the pin-wheels displays very long
periods before the key repeats, but there are subperiods
For this reason messages with the same pin settings on
the same wheels should not be too long, and the pin
s e t t i n g s o n t h e p i n - w h e e l s f p r t h e i m p o r t a n t t r a f fi c
s h o u l d b e c h a n g e d f r e q u e n t l y. 1 I n a d d i t i o n a l l o t h e r
possible variations should bd kept in mind and used.
The CX Machine with irregularj movement of the pin-wheels
brings the advantage that non-linear movement sequences
can be obtained. If certain mathematical conditions are
met in the compilation of the material for the keys,
t h e n t h e p e r i o d s o c c u r i n g w i l l b e s u f fi c i e n t l y l o n g .
In simple terms it can be said that the length of the
period is determined by the number of pin-wheels which
control another pin-wheel.
\ ^
-57-
3E720
The CXM Machine is a compromise between the other two
machines (C and CX). The movement scheme for the pin
wheels here is as follows:
The wheel I (from the left) turns regularly one step in
each operation. This wheel controls wheel II. Wheel III
is controlled by wheels I and II, wheel IV by the three
precedmg wheels, wheel V by its preceding wheels, and
wheel VI by its preceding wheels. All six wheels have
the same number of divisions, the length of the period
will be n , or with six wheels with 47 divisions will
have a length of about 1010. With this system only the
fi r s t w h e e l h a s s u b p e r i o d s w h i c h a f f e c t t h e d r u m s l i d e - ^
bars which are controlled by this wheel, while the Jf
remaining pin-wheels get an irregular movement. With
this machine somewhat simpler keying instructions can
be used than with the C or CX machines without endanger
i n g s e c u r i t y.
The three machines offer various advantages, and each
user has to decide for himself which machine he wants.
He has also to set up the instructions for the safe
use of his machines, which is dependent on their
deployment.
The numbers given in this section are hard to comprehend.
Even the number 10 corresponds approximately to the
distance from the earth to the sun in milimeters.
T h e n u m b e r s c i t e d h a v e s i g n i fi c a n c e o n l y a s f a r a s
they show that the possibilities for all machines of ^
the C-type are practically inexhaustible. But these v
numbers are meaningless if the user does not carefully
accept and exercise the instructions and does not make
full use of the possible variations.
The old rule is still true:
t h e q u a l i t y o f a m a c h i n e d e p e n d s l a r g l y o n i t s u s e r.
vp-kk-ak
AHB
*
-58-