Before approaching Claude Shannon’s contribution to Cryptography, one must look at his prior work in particular in the field of information theory, a field he theorized in his 1948 paper A Mathematical Theory of Information. Shannon introduced a lot of the ideas that were mentioned and developed in this revolutionary paper to the scientific community in his 1945 paper entitled A Mathematical Theory of Cryptography.
Indeed, during the Second World War, Shannon decided to join the Bell Labs, a research facility concentrating many prominent scientists of the time who decided to use their talent to serve the war effort. While he was working at the Bell Labs, the facility was in charge of many secret projects such as the development of the X system. The X system referred to “an encrypted radiotelephone system to connect Washington and London.” Although Shannon was not part of the project per se, he was asked to test the inscription scheme of the project. This inscription scheme was based on two very important concepts, namely “sampling” and “quantization.” “The idea was to approximate a continuous signal by a series of steps – as if we superimpose the continuous signal by what seems a stairway that goes up and down following the shape of the signal.” Sampling refers the action of choosing those steps while quantization refers to the action of defining the height of each step. This process enabled to approximate continuous signals with series of discrete steps. When applied to the telephone, it enabled the high command in both London and Washington to communicate with each other knowing that the Germans would never pick up on their conversations. One of the problems though was that since the message was broken down into steps before ...
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...ot describe how to achieve this outcome.
It is the discovering we just described that allowed Shannon to publish in 1949 his paper Communication Theory of Secrecy Systems in which he developed the concept of a Cryptosystem. To understand the revolutionary nature of this publication, we are now going to describe what cryptography was before its publication.
Polyalphabetic substitution ciphers were developed during the Renaissance period in Europe and were the dominant type of encrypting for confidential messages during both World Wars. The Second World War was one that was considered especially technological. Cryptography was very important and whoever would break the other side’s code would have an enormous advantage in the war. In the end, the British with the help of Alan Turing broke the German code “Enigma” and the Americans broke the Japanese code “Purple.”
One of Great Britain’s most important naval developments was the founding of the top-secret Office of Naval Intelligence, better known as Room 40. Specializing in cryptography, “the science of writing in secret code” in order to hide sensitive information, Room 40’s cryptanalysts worked around the clock to break the secret code. Decryption is vital in secret transmissions concerning strategic war movements, as the enemy will be looking to intercept information concerning movements and positioning. Great Britain was aided in that the German Navy started the war with three primary codes, and within four months the British Admiralty possessed physical copies of all three of them.
Wireless is a methodical account of the early development of wireless telegraphy and the inventors who made it possible. Sungook Hong examines several early significant inventions, including Hertzian waves and optics, the galvanometer, transatlantic signaling, Marconi's secret-box, Fleming's air-blast key and double transformation system, Lodge's syntonic transmitter and receiver, the Edison effect, the thermionic valve, and the audion and continuous wave. Wireless fills the gap created by Hugh Aitken, who described at length the early development of wireless communication, but who did not attempt "to probe the substance and context of scientific and engineering practice in the early years of wireless" (p. x). Sungook Hong seeks to fill this gap by offering an exhaustive analysis of the theoretical and experimental engineering and scientific practices of the early days of wireless; by examining the borderland between science and technology; depicting the transformation of scientific effects into technological artifacts; and showing how the race for scientific and engineering accomplishment fuels the politic of the corporate institution. While the author succeeds in fulfilling these goals, the thesis, it seems, is to affirm Guglielmo Marconi's place in history as the father of wireless telegraphy.
In 1942, World War II had been raging for three years. The United States of America have declared war upon the Axis powers following the devastating Japanese attack upon Pearl Harbor. At this point in the war the Allies are in a grave situation. German forces have pushed the British off mainland Europe, and the Japanese have conquered much of the Pacific region, coming increasingly nearer to the American mainland. In order to combat this rising threat, the American military headship began to search for viable alternatives to replace widely used established tactics. The motive for this search for irregular methods the fact that the Allied forces were not strong enough to meet the Axis powers on a conventional
Although this idea had been successfully implemented during World War I using the Choctaw Indian's language, history generally credits Philip Johnston for the idea to use Navajos to transmit code across enemy lines. Philip recognized that people brought up without hearing Navajo spoken had no chance at all to decipher this unwritten, strangely syntactical, and guttural language (Navajo). Fortunately, Johnston was capable of developing this idea because his missionary father had raised him on the Navajo reservation. As a child, Johnston learned the Navajo language as he grew up along side his many Navajo friends (Lagerquist 19). With this knowledge of the language, Johnston was able to expand upon the idea of Native Americans transmitting messages in their own language in order to fool enemies who were monitoring transmissions. Not only did the Code Talkers transmit messages in Navajo, but the messages were also spoken in a code that Navajos themselves could not understand (Paul 7).
The sender would type the message in plaintext (not encrypted) and the letters would be illuminated on a glass screen. With the press of each typewriter key the rotor would shift 1/26 of a revolution giving each letter a different encryption each time, which made the code so difficult to crack. Due to the complexity of the code the enigma became very useful for the Germans for radioing messages to u-boats. The cipher was finally broken when the British were able to capture some key documents from a German warship.
National Counterintelligence Center (NCC). 2010. Chapter 2: Magic. Volume 2: A Counterintelligence Reader – Counterintelligence in World War II.
Bletchley Park was the center of British code-breaking operations during World War II. The codebreakers, who worked regularly, sought to find the secret communications of the Axis Powers, especially the German Enigma and Lorenz ciphers. Bletchley Park was organized into sixteen different Huts, each with a different purpose. The codebreakers broke thousands upon thousands of codes countless times, that no one even kept track of how many codes were actually broken. They read messages from the German army, navy, air force, secret service, and even messages from the desk of Hitler. The Germans never suspected a thing. The codebreakers even cracked Italian and Japanese ciphers. The codebreakers, both male and female, helped win the war in North
The ever evolving method of cryptography, or sending messages through code, can be traced throughout the history of the world. Early Egyptians communicated through mysterious hieroglyphics. Ancient Greeks concealed secret messages beneath wax on tables or with tattoos on a slave’s head. During the Renaissance in Europe, citizens would use a substitution cipher to carry messages about political and religious revolutions. During World War I and previous battles, most countries used codes to contact their navy or army branches abroad, in case of enemy interception. Which subsequently brings us to World War II, and the major role that codebreaking played in the results of the war. Some of the main codebreaking events during World War II, the breaking
As if being a beautiful, talented actress was not enough, Hedy was also extremely intelligent. In addition to her film accomplishments, Hedy patented an idea that later became the crutch of both secure military communications and mobile phone technology. In 1942, Hedy and composer George Antheil patented what they called the “Secret Communication System.” The original idea, meant to solve the problem of enemies blocking signals from radio-controlled missiles during World War II, involved changing radio frequencies simultaneously to prevent enemies from being able to detect the messages.
When World War II broke out in 1939 the United States was severely technologically disabled. There existed almost nothing in the way of mathematical innovations that had been integrated into military use. Therefore, the government placed great emphasis on the development of electronic technology that could be used in battle. Although it began as a simple computer that would aid the army in computing firing tables for artillery, what eventually was the result was the ENIAC (Electronic Numerical Integrator and Computer). Before the ENIAC it took over 20 hours for a skilled mathematician to complete a single computation for a firing situation. When the ENIAC was completed and unveiled to the public on Valentine’s Day in 1946 it could complete such a complex problem in 30 seconds. The ENIAC was used quite often by the military but never contributed any spectacular or necessary data. The main significance of the ENIAC was that it was an incredible achievement in the field of computer science and can be considered the first digital and per...
Codes have been around for centuries ranging from wax, invisible ink, Morse code, the Enigma used by the Germans during World War II and now steganographic. Steganography is the latest form to insidiously hide information over the Internet without a trace of a file being altered. You are able to hide messages within images, voice or music. Steganography is an ancient method of hiding messages. Today messages are hidden in images and music. Steganography can be traced back to the ancient Greek who would write messages on tablets and cover them in wax. This made the tablets look blank and unsuspicious (Kolata, F4). Citizens of ancient civilizations would tattoo messages on their shaved heads. They would then let their hair grown in and travel across enemy lines to deliver the message (Seper, G1). During World War II the Allies placed a ban on flower deliveries with dates, crossword puzzles and even report cards (Kolata, F4) for fear of a message being hidden with in. Steganographers first alter their data by using encryption and then place the image into a pre-select image. Steganographers look for a piece of code that would be the least significant and look the least altered to the human eye (Kolata, F4), being as inconspicuousness and random as possible. This makes the messages undetectable unless you knew that there is a message hidden and you were able to crack the code.
Cryptography was first used long before the invention of computers. One well-known system was attributed to the reign of Julius Caesar (Klein ix). Another example is the famous Zimmerman telegraph, which was sent from Germany to Mexico during World War I (ix). In a more modern setting, cryptology was mainly used by the government until the late 1970s (Simpson 1). This is largely due to the fact that computers were too expensive, so not many households or businesses had them (1). However, after the computer revolution, cryptology became more public, especially in the business industry where there was a greater need to secure things like transactions (1).
The length of the key for the encryption can vary from being very short to extremely long, and the length of the message being encrypted. The protection of data being transferred between ATMs and the bank, and the use of cell phones, is the most common everyday encounter with encryption. To encrypt and decrypt information, a cipher is used. In a cipher, there is a set of well-defined steps that can be followed to encrypt and decrypt messages.
In this era when the Internet provides essential communication between tens of millions of people and is being increasingly used as a tool for security becomes a tremendously important issue to deal with, So it is important to deal with it. There are many aspects to security and many applications, ranging from secure commerce and payments to private communications and protecting passwords. One essential aspect for secure communications is that of cryptography. But it is important to note that while cryptography is necessary for secure communications, it is not by itself sufficient. Cryptography is the science of writing in secret code and is an ancient art; In the old age people use to send encoded message which can be understand by the receiver only who know the symbolic and relative meaning of that encoded message .The first documented use of cryptography in writing dates back to circa 1900 B.C. Egyptian scribe used non-standard hieroglyphs in an inscription. After writing was invented cryptography appeared spontaneously with applications ranging from diplomatic missives to war-time battle plans. It is no surprise, then, that new forms of cryptography came soon after the widespread development of computer communications. In telecommunications and data cryptography is necessary when communicating in any untrusted medium, which includes any network, particularly the Internet [1].Within the context of any application-to-application communication, there are some security requirements, including: