Section 1.2
Development of Cryptography
Task: Research on the development of cryptography and fill up the table below
with the major events that occurred during each period of time.
Read up on the ciphers you come across in your research and other
classical ciphers.
1900 BC
600 BC
500 BC
50 BC
800
1500
It started 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. 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.
Hebrew scribes writing down the book of Jeremiah used a reversed-alphabet simple
substitution cipher known as ATBASH. (Jeremiah started dictating to Baruch in 605 BC
but the chapters containing these bits of cipher are attributed to a source labeled ``C''
(believed not to be Baruch) which could be an editor writing after the Babylonian exile
in 587 BC, someone contemporaneous with Baruch or even Jeremiah himself.)
ATBASH was one of a few Hebrew ciphers of the time (SANS).
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.
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.
Cryptanalysis and frequency analysis leading to techniques for breaking
monoalphabetic substitution ciphers are developed in A Manuscript on Deciphering
Cryptographic Messages by the Muslim mathematician, Al-Kindi (Alkindus), who may
have been inspired by textual analysis of the Qur'an. He also covers methods of
encipherments, cryptanalysis of certain encipherments, and statistical analysis of
letters and letter combinations in Arabic.
1518 - Johannes Trithemius' book on cryptology
1553 - Bellaso invents Vigenère cipher
1585 - Vigenère's book on ciphers
1600
1800
1900
1920
1940
1586 - Cryptanalysis used by spy master Sir Francis Walsingham to implicate Mary
Queen of Scots in the Babington Plot to murder Queen Elizabeth I of England. Queen
Mary was eventually executed.
1641 - Wilkins' Mercury (English book on cryptology)
1809 - 14 George Scovell's work on Napoleonic ciphers during the Peninsular War
1831 - Joseph Henry proposes and builds an electric telegraph
1835 - Samuel Morse develops the Morse code
1854 - Wheatstone invents Playfair cipher
1854 - Babbage's method for breaking polyalphabetic ciphers (pub 1863 by Kasiski)
1855 - For the English side in Crimean War, Charles Babbage broke Vigenère's autokey
cipher (the 'unbreakable cipher' of the time) as well as the much weaker cipher that is
called Vigenère cipher today. Due to secrecy it was also discovered and attributed
somewhat later to the Prussian Friedrich Kasiski.
1883 - Auguste Kerckhoffs' La Cryptographie militare published, containing his
celebrated laws of cryptography
1885 - Beale ciphers published
1894 - The Dreyfus Affair in France involves the use of cryptography, and its misuse, in
regard to false documents.
1915 - William Friedman applies statistics to cryptanalysis (coincidence counting, etc)
1917 - Zimmermann telegram intercepted and decrypted, advancing U.S. entry into
World War I.
1919 - Edward Hebern invents/patents first rotor machine design a rotor machine is
an electro-mechanical device used for encrypting and decrypting secret messages. A
rotor machine is an electro-mechanical device used for encrypting and decrypting
secret messages
1921 - Washington Naval Conference - U.S. negotiating team aided by decryption of
Japanese diplomatic telegrams. The message revealed the lowest naval ratio that
would be acceptable to Tokyo; U.S. negotiators used this knowledge to push the
Japanese to giving in.
1924 - MI8 (Herbert Yardley, et al) provide breaks of assorted traffic in support of US
position at Washington Naval Conference; aiding other cryptanalysts to break more
codes.
1932 - first break of German Army Enigma by Marian Rejewski in Poland, giving them
a jumpstart British reading of the Enigma- a rotor machine used to generate ciphers
for the encryption and decryption of secret messages.
1931 - The American Black Chamber (cryptography headquarters) by Herbert O.
Yardley is published, revealing much about American cryptography, giving people an
opportunity to learn more about it.
1940 - break of Japan's PURPLE machine cipher by SIS team. However, U.S. Naval base
at Pearl Harbor surprised by Japanese attack, despite U.S. breaking of Japanese codes.
U.S. enters World War II
April 1943 - Admiral Yamamoto, architect of Pearl Harbor attack, is assassinated by
U.S. forces who know his itinerary from decoded messages. This shows that the lives
of cryptographers are fragile.
December 1943 - The Colossus computer was built, by Thomas Flowers at The Post
Office Research Laboratories in London, to crack the German Lorenz cipher (SZ42). It
was so advanced that the computer had to be destroyed, lest it fell into the wrong
hands.
1968
1976
1991
2000
2010
1946 - VENONA's first break into Soviet espionage traffic from early 1940s
Navajo codetalkers were Navajo people who were employed to transmit and deliver
secret messages in the battlefield. It was extremely useful as their language was
completely differently structured as compared to the commonly used ones. Up till
today, the Navajo language cannot be cracked without the knowledge of the language
itself.
1968 - John Anthony Walker walks into the Soviet Union's embassy in Washington and
sells information on KL-7 cipher machine. The Walker spy ring operates until 1985.
1974 - Horst Feistel develops Feistel network block cipher design.
1976 - the Data Encryption Standard was published as an official Federal Information
Processing Standard (FIPS) for the United States.
The Data Encryption Standard was published as an official Federal Information
Processing Standard (FIPS) for the United States. The Data Encryption Standard (DES)
is a cipher (a method for encrypting information) selected as an official Federal
Information Processing Standard (FIPS) for the United States in 1976 and which has
subsequently enjoyed widespread use internationally. The algorithm was initially
controversial with classified design elements, a relatively short key length, and
suspicions about a National Security Agency (NSA) backdoor. DES consequently came
under intense academic scrutiny which motivated the modern understanding of block
ciphers and their cryptanalysis.
Diffie and Hellman publish New Directions in Cryptography.
Phil Zimmermann releases the public key encryption program PGP along with its
source code, which quickly appears on the Internet. Pretty Good Privacy (PGP) is a
computer program that provides cryptographic privacy and authentication. PGP is
often used for signing, encrypting and decrypting e-mails to increase the security of email communications.
RSA Security Inc. released their RSA algorithm into the public domain, a few days in
advance of their U.S. Patent 4,405,829 expiring. Following the relaxation of the U.S.
government export restrictions, this removed one of the last barriers to the worldwide distribution of much software based on cryptographic systems
Quantum cryptography, or quantum key distribution (QKD), uses quantum mechanics
to guarantee secure communication. It enables two parties to produce a shared
random bit string known only to them, which can be used as a key to encrypt and
decrypt messages. An important and unique property of quantum cryptography is the
ability of the two communicating users to detect the presence of any third party
trying to gain knowledge of the key. This results from a fundamental part of quantum
mechanics: the process of measuring a quantum system in general disturbs the
system. A third party trying to eavesdrop on the key must in some way measure it,
thus introducing detectable anomalies. By using quantum superpositions or quantum
entanglement and transmitting information in quantum states, a communication
system can be implemented which detects eavesdropping. If the level of
eavesdropping is below a certain threshold a key can be produced which is
guaranteed as secure (i.e. the eavesdropper has no information about), otherwise no
secure key is possible and communication is aborted. The security of quantum
cryptography relies on the foundations of quantum mechanics, in contrast to
traditional public key cryptography which relies on the computational difficulty of
certain mathematical functions, and cannot provide any indication of eavesdropping
or guarantee of key security.