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Cryptography Club Practice Ciphers 9-27-2003 1. To those friends considering, it is always news, but all filled ciphers disturb happiness with varied answers! By TRYIT --This is a concealment cipher. There is a message hidden within this sentence, the key is figuring out how to read off the letters. The following cipher was taken from Cryptanalysis [a study of ciphers and their solution] by Helen Fouche Gaines. This book offers a very good introduction to elementary cipher systems and their cryptanalysis. You can find a copy of this book in the UCF library. 2. TADOHSFWEURLRROEEEMDITUGSOSEMBE.UEL.CGEBHAS.PISRLNK.EEN. --This is a columnar transposition cipher. There is a message hidden within the letters. The key is figuring out how many letters to skip when reading off the letters. Another method is to write the cipher into columns. Try using two columns and see if any text can be read, if that doesn’t work, try using three and so forth. A variation of this cipher, the Double Columnar Transposition Cipher was the official field cipher of the United States Army during WWII. 3. VXMDUJAJARCQVNCRLLXDUMKNLXWBRMNANMANVJRWMNAARCQVNCRL --This is called a shift cipher. Each letter has been shifted up the alphabet by the same number. The key to solving this cipher is to determine the amount each character has been shifted by. The following cipher was taken from Elementary Cryptanalysis by Abraham Sinkov. This book offers a very good introduction to elementary cipher systems and the mathematical notation involved. You can find a copy of this book in the UCF library. --Hint: _______ Ball 4. The Playfair cipher system works with a table and three rules. - If two letters are in the same row, shift them one unit to the right and wrap around the row if necessary. - If two letters are in the same column, shift them one unit downward and wrap around the column if necessary. - If two letters are not in the same row or column, replace each letter by the letter that is in its row and in the column of the other letter. Using the table below, decipher the following ciphertext: P L A Y F IJ R B C D E G H K M N O Q S T U V W X Z EG MN FQ QM KN BK SV VR GQ XN KU.