Chapter 3: Cryptography

3.1 The history

20 8 9 19 9 19 1 19 5 3 18 5 20 (A coded message 

Picture some good ol' boys sitting around a poker table, smoking cigars, and drinking at the local saloon. Pistol Jack says, "I have an RC2, but I will raise you with a DES." Caught off guard, Tex Hunter says, "Well, if that is how you want to play, I will spike you with a triple-DES and match your RC2 with an MD5."

This all sounds like some high-stakes poker game, but what about those peculiar acronyms? In this game, our cowboys from west Texas were betting various encryption types. Now, they had no idea what they had or even what they were saying. Your job, if you choose to accept it, is to gain an understanding of what the acronyms mean and the impact this can have on how you do business on the Internet. So let's start with a bit of history. Once upon a time someone had a secret. . . .

Both Pistol Jack's and Tex Hunter's family histories trace back to a group of early pioneers known as the Securites. Pistol Jack's and Tex Hunter's ancestors had enemies known as the "Hacker Dudes." These bandits would listen in on the conversations that the Securites were having around the campfire about the next day's hunt. The Hacker Dudes would get the location of the next buffalo hunt and then go and scare off all the buffalo befofre the Securites could get their kill for the day. The conversation would go like this: Texasawa would say, "I saw buffalo out beyond the Crooked Sky. Let's go and get some, and afterwards we can have a feast." Then Jackawa would say, "Yup." But, thanks to the Hacker Dudes, our friends would trek to the plains only to find no buffalo. Well, Texasawa and Jackawa figured out what was going on, so they created a complex code that would keep the bandits from finding out where the buffalo were. The code went like this: Texasawa would say, "I saw some buffalo out beyond the Crooked Sky today" wink, wink. Jackawa would say, "Yup." The translation of this was "The buffalo are really out beyond the Raging River." So the bandits would go off to the wrong place, and Jackawa and Texasawa could kill their buffalo!

Cryptography is one of the oldest systems of protecting data. Historians have found evidence of this dating back at least 4,000 years. Cryptography is believed by many to have been created around 2000 B.C., in Egypt. The ancient Chinese also used codes to hide the meaning of their works. Over the years, various systems have been used, from a simple substitution of letters or numbers to complex mathematical theorems. One of the simplest forms of cryptography is a substitution of letters for numbers. This idea was a popular prize in cereal boxes many years ago.

Table 3.1





















































Granted, the Hacker Dudes may have been able to figure this one out, but most codes are not this simple. Cryptology is the process of changing text into some type of code or text, called ciphertext, that is not readable to the general reader. Ciphertext is the result of using a key (sometimes secret) and creating a body of text that needs to be deciphered. A key is typically some quantity or mechanism to encrypt or decrypt text or ciphertext.

Now that we know what a key is and what ciphertext is, we can encrypt and decrypt data. Using this chart, here is an example. Start out with "HELLO." Encrypting it with our code, we have "8 5 12 12 15." The formula follows:

Text  Encryption System  ciphertex HELLO  Table Look-Up  8 5 12 12 1 

Now using the same key, we will decrypt the ciphertext.

Ciphertext  Encryption System  Tex 8 5 12 12 15  Table Look-Up  HELL 

Throughout history, all governments have used some type of encryption. During the Middle Ages, encryption was used quite heavily. Many of the early European governments used cryptography to communicate with government ambassadors.

Over time, encryption was enhanced by the use of various tools. One was a Cipher Wheel invented by Thomas Jefferson. This tool consisted of a set of wheels, each with a random order of the letters of the alphabet. The key to the system is the order of the wheels. Each wheel was placed on an axle. The message was encoded by aligning the letters along the axis of the axle such that the message was created. Any other row of aligned letters could then be used as the ciphertext. The decryption required the person who received the message to configure the letters of the ciphertext along the axis and find a set of the letters that was readable. The recipient then had a readable message.

Go to your favorite search engine and do a search for "Cryptography and Shakespeare." There are many listings for URLs and books on the use of code in Shakespearean works. Many scholars believe that either Francis Bacon, Christopher Marlowe, or Edward de Vere actually wrote the various plays and sonnets and that the clues are encoded in the writings. It may be that if you somehow decoded the plays, you could perhaps find that Romeo actually loved a girl named Ethel!

As you can see, encryption and cryptography are not new and are not a technology created for the Internet. They are as old as language itself and have been used for many different purposes, mostly to keep secrets from an adversary. If you study any war throughout history, you will find the use of some type of encryption. During the U.S. Civil War, both the Northern and Southern armies used ciphers. During World War II, the Americans broke a Japanese code known as "Purple." The ability to decrypt the information contained in the code assisted the Americans in battles with Japan. The "Purple" team was led by William F. Friedman, who, during his spare time at Cornell University, worked with cryptologists in trying to prove that Francis Bacon, through his encrypted signature in plays, actually wrote works credited to Shakespeare! Also in World War II, the Navajo Native American language was used by American military forces to transmit messages by telephone and radio. Its syntax and tonal qualities, not to mention dialects, make it unintelligible to anyone without extensive exposure and training. It has no alphabet or symbols and is spoken only on the Navajo lands of the American Southwest. One estimate indicates that fewer than 30 non-Navajos could understand the language at the outbreak of World War II. Check out Windtalkers (MGM-2002). This movie, based on actual events during World War II, explains how U.S. troops utilized Navajo Indians and their complex language to communicate without the Japanese intercepting messages. Nicolas Cage and Christian Slater play Marines assigned to act as bodyguards to protect the Navajo soldiers. URL

Also during World War II, German codes were predominantly based on the "Enigma" machine. On an old farm outside of London, known as Bletchley Park, Alan Turing, a leading mathematician, developed an electromechanical machine that would crack the code of the Enigma keys. With this system and the capture of Enigma machines from U-boats, the Allies were able to learn of the planned activities of the U-boat, panzer, and bombing raids. For a picture of the Enigma machine see or A great Enigma emulator in the form of an applet can be found at

Here is some code to make with this applet. See if you can crack an Enigma code from World War II.


E-mail the results to <>. Sorry, no prizes for this!

Internet Security(c) A Jumpstart for Systems Administrators and IT Managers
Internet Security: A Jumpstart for Systems Administrators and IT Managers
ISBN: 1555582982
EAN: 2147483647
Year: 2003
Pages: 103
Authors: Tim Speed, Juanita Ellis
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