History of the encryption

1900 BC
All begann about 1900 years BC in the Egypt town called Menet Khufu near the river Nil. Khnumhotep II was an architect of Pharao Amenemhet II. He built some monuments for the Pharao which had to be documented. As you may imagine, this notes were not thought for every eyes.
	The writer of Khnumhotep II had the idea to exchange some words and text parts within the document (substitution). In case the document would been stolen, the thief would not find the correct way to the gold treasure. Perhaps you would find him years later starved in the catacombs of the pyramid.

1500 BC

Assyrian merchants were using "intaglios" which is a piece of flat stone carved with symbols for their identification. The modern trading with digital signatures was invented. It was also the time when cultures like Egypt, China, India and Mesopotamian developed Steganography:

Tattoos with messages on the head of slaves. Unfortunately you had to wait until the hair was grown again. Decryption was done at the hair dresser.
Markings in the wood of a wax plate. The markings were hidden with new wax. To decrypted you just had to melt the wax.
Messages in the stomach of a hunted animal

475 BC

Thucydides tells of orders delivered to the Spartan prince and general Pasanius in 475 BCE via what could be the earliest system of military cryptography, the skytale. As a device for conveying ciphers, the skytale consists of a staff of wood around which a strip of papyrus is tightly wound. Writing the message down the length of the staff, the parchment is unwound to conceal the message. Since the message appears to be nothing more than a series of disconnected letters, its true meaning remains concealed. However, it seems unlikely that such a technique was ever used in this way. Ancient texts by Aeneas the Tactician, Polybius, and others describe further methods for concealing messages but none of these actually seem to have been used either (Glikman).

The secret key of the text is the circumference of the wood. With the wrong circumference, the message is unusable. If the wood matches, you are able to read the message. Attacking the skytale was no big thing, this at least when you understood the principle of the algorithm. Imagine the paper strip would look like the example below:

S I E I Y H I T I E P I C I N L T E H S Z D O ! E T I E G R D G R R H A E K A E S Z R P

If you would try to break it with a circumference of c = 4, the result would look like:

S Y I C T Z E G R E S
I H E I E D T R R K Z
E I P N H O I D H A R
I T I L S ! E G A E P

which does not make a lot of sense. If you try with a circumference of c = 6, the result looks much better. (Huynh)

S I C H E R H E
I T I S T D A S
E I N Z I G E Z
I E L D E R K R
Y P T O G R A P
H I E !

100-50 BC

The Caesar Cipher was developed during the roman empire. The code was based on the replacement of each plaintext character with a new shifted character in the alphabet. The secret key of the shift between the plaintext and the ciphertext. As example, if the shift is 5 and the plaintext is

SECRET FOR YOU

the ciphertext would look as in the example below.

XJHWJY KTW DTZ

This because you calculate plaintext + shift (Secret Key) = ciphertext which is
S + Shift (5) = X.

950-1100 AC

The runic stones were used by Scandinavian Viking civilization. Their mysterious messages may still be seen throughout the countryside of the far northland of Europe and the Atlantic islands. There are many arguments surrounding the origin of the runes some saying that they originated from Turkish alphabets whereas others Latin and Greek. The latter theories are the most popular since there are many common characters to be found in these that also appear in the runic system.

Runes mathematic

1466 AC
Leon Battista Alberti (1404-1472) has developed a machine for a mechanic encryption. The machine is based on the Cesar algorithm. During the 1460's, while walking through the gardens of the Vatican, Leon Alberti had a casual conversation about cryptography with the pontifical secretary, Leonardo Dato. Obviously there he got the idea of invented and published the first polyalphabetic cipher, designing a cipher disk (known to us as the Captain Midnight Decoder Badge) to simplify the process. This class of cipher was apparently not broken until the 1800's.
Cryptography was widely used by heads of state and had mostly been broken by frequency analysis. This meeting apparently got Alberti to consider a new possible method for encryption. Using more than one set of letters to encrypt the message which would hopefully confuse any cryptanalysts. (2600)

1553-1563 AC

Giovan Batista Belaso introduced the notion of using a passphrase as the key for a repeated polyalphabetic cipher. He classified ciphers as transposition, substitution and symbol substitution (use of a strange alphabet). He suggested use of synonyms and misspellings to confuse the cryptanalyst. He apparently introduced the notion of a mixed alphabet in a polyalphabetic tableau.

The following compact table provides 26 alphabets, each labeled with a letter of the alphabet:

B C D E F ZABCDEFGHIJKLMNOPQRSTUVWXY
G H I J K UVWXYZABCDEFGHIJKLMNOPQRST
L M N O P PQRSTUVWXYZABCDEFGHIJKLMNO
Q R S T U KLMNOPQRSTUVWXYZABCDEFGHIJ
V W X Y Z FGHIJKLMNOPQRSTUVWXYZABCDE

B G L Q V ABCDEFGHIJKLMNOPQRSTUVWXYZ
C H M R W BCDEFGHIJKLMNOPQRSTUVWXYZA
D I N S X CDEFGHIJKLMNOPQRSTUVWXYZAB
E J O T Y DEFGHIJKLMNOPQRSTUVWXYZABC
F K P U Z EFGHIJKLMNOPQRSTUVWXYZABCD

Thus, for alphabet Q, the top row begins KLMNO... and the bottom row begins ABCDE..., and so K becomes A, Q becomes G, and A becomes Q in that alphabet. This polyalphabetic algorithm has some similarities with the Vigenère algorithm and is also often miss-named as it.

1586 AC
		Blaise de Vigenère (1523-1596) wrote a book on ciphers, including the first authentic plaintext and ciphertext autokey systems. The Vigenère encryption is the most famous polyalphabetic algorithm. The main idea of this method was to use different monoalphabetic encryptions in change. For the encryption of a message with Vigenère you need the keyword and the Vigenère square. . Here the message is hidden among the stars and is decoded with a shared text.
Without the keyword you cannot define which secret character belongs to the according plaintext character. Use can use any keyword you want. For demonstrating the encryption method we choose the keyword "hallo" and use it with the plaintext we want to encrypt.

	Keyword:	H A L L O H A L L O H A L
	Plaintext:	k r y p t o g r a p h i e
	Ciphertext:	R R J A H V G C L D O I P

For getting this result you need to find the ciphertext letter in the matrix according to the x-axis (k) and the y-axis (H). The result is obviously R.

a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z B C D E F G H I J K L M N O P Q R S T U V W X Y Z A C D E F G H I J K L M N O P Q R S T U V W X Y Z A B D E F G H I J K L M N O P Q R S T U V W X Y Z A B C E F G H I J K L M N O P Q R S T U V W X Y Z A B C D F G H I J K L M N O P Q R S T U V W X Y Z A B C D E G H I J K L M N O P Q R S T U V W X Y Z A B C D E F H I J K L M N O P Q R S T U V W X Y Z A B C D E F G I J K L M N O P Q R S T U V W X Y Z A B C D E F G H J K L M N O P Q R S T U V W X Y Z A B C D E F G H I K L M N O P Q R S T U V W X Y Z A B C D E F G H I J L M N O P Q R S T U V W X Y Z A B C D E F G H I J K M N O P Q R S T U V W X Y Z A B C D E F G H I J K L N O P Q R S T U V W X Y Z A B C D E F G H I J K L M O P Q R S T U V W X Y Z A B C D E F G H I J K L M N P Q R S T U V W X Y Z A B C D E F G H I J K L M N O Q R S T U V W X Y Z A B C D E F G H I J K L M N O P W X Y Z A B C D E F G H I J K L M N O P Q R S T U V S T U V W X Y Z A B C D E F G H I J K L M N O P Q R T U V W X Y Z A B C D E F G H I J K L M N O P Q R S U V W X Y Z A B C D E F G H I J K L M N O P Q R S T V W X Y Z A B C D E F G H I J K L M N O P Q R S T U W X Y Z A B C D E F G H I J K L M N O P Q R S T U V X Y Z A B C D E F G H I J K L M N O P Q R S T U V W Y Z A B C D E F G H I J K L M N O P Q R S T U V W X Z A B C D E F C H I J K L M N O P Q R S T U V W X Y

The first attack was done by Friedrich Wilhelm Kasiski 1863, the 2nd was done by William Frederick Friedman 1925. Both methods were very important for further cryptoanalysis.

1623 AC

Sir Francis Bacon described a cipher which now bears his name -- a bilateral cipher, known today as a 5-bit binary encoding. He advanced it as a steganographic device -- by using variation in type face to carry each bit of the encoding.

The plaintext, then, is "F S B I A C C E N R I". It appears on the "FORTH." (+4) line in which "A" = "e". Bacon's 21 letter alphabet, ending in "T V Y", remains the same. "FS" is Bacon's own abbreviation of his first name while "BIACCEN" is yet another phonetic spelling of his surname.

1790 AC

Thomas Jefferson devised an ingenious, easy, and secure method to encode and decode messages: the wheel cipher. During the American Revolution, Jefferson had relied primarily on messengers to hand- carry sensitive letters, but codes became an essential part of his correspondence when he was America's minister to France (1784-1789) since European postmasters opened and read all letters passing through their command.

Jefferson's wheel cipher consisted of twenty-six cylindrical wooden pieces, each threaded onto an iron spindle. The letters of the alphabet were inscribed on the edge of each wheel in a random order. Turning these wheels, words could be scrambled and unscrambled. Although Jefferson apparently abandoned use of the wheel after 1802, it was "re- invented" just prior to World War I and used by the United States Army and other military services.

As an example, the sender of the message shown in the picture,

Thomas Jefferson wheel cipher

would spell the message out, and then look to any other line of text -- possibly the one directly above, beginning with the letter "M." The sender would then copy the letters from that line into the letter. The recipient of the coded message would spell out the random- seeming letters

MZNCSK YONSLKTRF AJQQB RTXYUK

on his identical cipher and then glance at the other lines of text, looking for the one line that made sense. (Lucas)

1917 AC
William Frederick Friedman, later to be honored as the father of US cryptanalysis, was employed as a civilian cryptanalyst at Riverbank Laboratories and performed cryptanalysis for the US Government, which had no cryptanalytic expertise of its own. He went on to start a school for military cryptanalysts at Riverbank -- later taking that work to Washington and leaving Riverbank.

During this time period, America became involved in world war I. Encrypted messages that were intercepted where given to Friedman to decipher, he was successful in decrypting every one. In the 1920's, he became the first person to apply mathematical principals to cryptology. During this same time period, mechanical machines were invented, which had multiple rotor parts, thus producing more complicated and complex codes. Friedman began using mathematics to reconstruct these complex machines which enabled him to decrypt even the most complicated codes produced.

Throughout the 1930's, Friedman continued to break even the most complex of codes. During world war II he and his staff worked secretly at breaking the enemy code. In 1941, code that was being secretly sent from Japan to Japanese officials in the U.S. was sent to Friedman and his staff for deciphering.

These complex codes could be quickly deciphered due to Friedmans invention of "The Purple Machine" (given its name from the Purple cipher in which the Japanese messages were exchanged). Copies of the machine were also given to the British enabling them to decode messages sent between Japanese officials and Nazi Germany. (SANS)

1920 AC
The rotor machine was developed 1920. There is no official inventor known. The rotor machine is a electromagnetic encryption device. A rotor consists of two circular plains which are electronically isolated. The alphabetic character are annular arranged on both sides of the rotor. Each character has its own electric contact which is connected with only one character on the other side of the rotor. Means this is a classical substitution.

If you turn the rotor after each typed character, you turn the machine into a polyalphabetic substitution machine with a period of 26.

For improving the security you can add more rotor to the machine. Each rotor is directly connected to the next rotor in the row. This is another substitution which is not fixed as within the rotor. Because of this technique, a successful cryptoanalysis is very difficult.

1926 AC
Willi Korns Enigma machine was not a commercial success but it was taken over and improved upon to become the cryptographic workhorse of Nazi Germany in the area of radio traffic. Korn was not satisfied with the construction of the available rotor machines, so he made his own construction. The Enigma I had 3 rotors and was used by the German army. 1942 possessed the German marine an Enigma with 4 rotors in total. During the world war II, the amount of rotors increased with the idea to improve the security of the messages.

The "Tabs" Bombe as it was called by those involved at the time, was the main machine used by the British to break the German Enigma codes. It was developed from a Polish concept and then significantly enhanced by the Mathematician Alan Turing (developer of the Turing machine and founder of the artificial intelligence). Gordon Welchman devised a further improvement called the diagonal board and it was this machine which was built by BTM at Letchworth under the leadership of H. Keen.

At least 200 of these 1000kg machines were built. They were over 2.1m long, 2m high and 60cm deep and were produced throughout the five year period of the war.

The Enigma was broken by the Polish mathematician, Marian Rejewski, based only on captured ciphertext and one list of three months worth of daily keys obtained through a spy. Continued breaks were based on developments during the war by Alan Turing, Gordon Welchman and others at Bletchley Park in England. (SANS)

1950 AC

On the 11th of January 1963 the USA and UdSSR finished the Cuba crises with a common agreement. In the same year the "hot line" between Kennedy and Chruschtschow was established for a faster and more secure message transmission in case of a crisis.

The encryption in Moscow and Washington was done with the ETCRRM strip-mixer series.

This machine used "once- only" punched paper tape as a key stream to encrypt teleprinter tape messages. ETCRRM was designed for low speed start-stop or synchronous applications and especially with a teleprinter as an input or output device.

1952 AC

The CX-52 was made by Boris Hagelin who founded Crypto AG in Switzerland.

The CX-52 uses six pinwheels, each having 47 pins which can be set in either active or inactive positions individually. Each wheel can be set up in over 120,000,000,000,000 ways, but only about half that number constitutes "good" keys. The positions of the pins on the wheels together with the wheel order - the wheels can be arranged in 6!, or 720 different ways - constitutes one of two variable keying elements.
The other, is the arrangement of a series of lugs on a bar drum. The bar drum has 32 bars and the first 27 bars have a movable lug each, the rest of the bars are equipped with stationary lugs which help to move the pinwheels in a complex way (see below about the movement of the pinwheels).
Each of the movable lugs can be set in one of six different positions (corresponding to the six pinwheels). The manufacturer states that the lugs must be placed, so that six intervals arise, which, when added together in all possible ways, can form all numbers between zero and twentyfive. One good arrangement may look like this (the x:s marking positions with lug set).

The destroyed CX-52 is a remainder of Dag Hammarskjöld, he was the UNO delegated of Sweden between 1951-1961.

1921 AC
Ivar Kreuger was known as the king of matches. He was one of the richest man on earth. For protecting the communication between the different branch offices he was using lever encryption. On the climax of the world wide recession in 1931, the empire broke down. Ivar Kreuger died 1932 under mysterious circumstances.

1922 AC
The wheel ciphers was originally developed by Jefferson in 1790 AC. The most famous device was the M-94 of the US army and the CSP-642 of the Japanese. The M-94 was used from 1922 until 1943. The M-94 consisted out of 25 aluminum cylinders. For security reasons they needed to keep the arrangement and what cylinders were chosen secret. There were plenty of different cylinders to chose from.

1923 AC
The Peterson International Code was used for telegraph security in the US.

1924 AC
The Kryha cryptograph had a number of variations. It had two disks, each with a scrambled alphabet that could be changed by the user. One disk moved for each letter enciphered. The movement was controlled by a pinwheel; if there were, on the pinwheel at one place, five teeth out followed by one pushed in, then that caused the moving disk to move five places forwards for one letter. (Savard)

1939 AC
William F. Friedman starts in 1939 the development of the Sigfoy M-325 which is an elegant copy of the German Enigma. Friedman sold thousands of these devices for US $60 each. The US government got also interested in the M-325, after testing it they found out that the M-325 was not only unreliable but it was also cryptographically weak. It was called the flop of Friedman.