Confederate Cipher Disk

Simran, Lovjoat, Arshdeep, ZohaibTEAM SALL-E

History Cipher Disks were invented by Leon Battista

Alberti, a famous Italian philosopher and architect in 1467. Fundamentally, involving two rotating rings that line up two different letters or numbers which ciphers the text. (Cipher meaning a method of altering the plaintext)

Used during Civil War At the rear of the disc is the text Richmond, VA,

the home town of the confederacy.

History Cont. Vigenère Cipher was simple enough to use to

be a field cipher. Used during the American Civil War (1861-

1865) The war between the North (Union) and the

South (Confederates) Union usually cracked the confederates

messages.

Creator Francis LaBarre, a gold and silver

worker Based on the Vigenère Cipher A mechanical wheel cipher consisting of two

concentric disks, each with the 26 letters of the Latin alphabet, that was used for the encryption of messages.

Purpose The disk was used for encryption

of secret messages of the Confederacy during the American Civil War (1861-1865)

Key Short key phrase said in a private previous

conversation A polyalphabetic cipher disk that was a

combination of the Caesar Cipher and the Vigenère Cipher

Examples “R” is the default adjustment letter and key

number “1212”, the inner disk turns so that “R” and the number “1212” coincide

The signal adjustment “2212”, “3”, “1122”, “333”, indicates “W” was adjustment letter, and 1122 the key number completing the cipher combinations (“W” coincides with “1122”)

-Note: “2212” being “W” in the non-ciphered code

Only five are known today in existence.

The Navajo Code Talkers

History Philip Johnston realized that the Navajo languages was

very complex and was not written down. The code was used for troop movements, tactics, order, and transmit info, with the use of native dialects over radios and telegraphs.

The language was primarily used during WWII, Korean war, and was retired after the Vietnam war.

On May 1942, 29 recruits attended boot camp and was the first group that made the code.

Creator Philip Johnston proposed the idea to use the

Navajo language as code during WWII Chester Nez, last of the original Navajo Code

talkers of WWII dies at 93.

Purpose During WWII the allies needed an encryption

they realized that Navajo language was very difficult

The navajos would say random words and then write their english equivalent and would use 1st letter to make a word.

Examples wol-la-chee (ant), tse-nill (axe) tsah (needle) be-la-sana (apple) ah-keh-di-gini (victor) Tsah-ah-dzoh (yucca) Besh-lo (iron fish) meant submarine Dah-he-tih-hi (humming bird) meant fighter plane

How the Code was Broken

Most letters had more than one Navajo word representing them. Not all words had to be spelled out letter by letter.

developers of original code assigned Navajo words to represent about 450 frequently used military terms that didn’t exist in Navajo language

Reference http://www.cryptomuseum.com/crypto/usa/ccd/

index.htm http://www.nsa.gov/kids/ciphers/ciphe00005.

shtm http://www.history.navy.mil/faqs/faq61-2.htm

http://navajocodetalkers.org/navajo-code-talkers-facts/