Transposition Cipher

1. Transposition Cipher CIS 451 Ritika Arora Brett Tedeschi Kelechi Ukaegbu Devon Woscinski Paul Mandal Abdul Smith

2. Background Information • 5th century B.C., the Spartans used a transposition cipher called a Scytale. • Scytale utilized a cylinder with a ribbon wrapped around one end. • The message was written across the ribbon then unwrapped from the cylinder. Only someone with an identical diameter cylinder could re-wrap and read the message. • Pig-latin is a form of transposition cipher • oo-day oo-yay emember-ray ig-pay atin-lay?

3. Transposition Cipher • Do not have to write plaintext row by row • Can follow different patterns (zig-zags, vertically or diagonally, spirals in or out, or clockwise or counterclockwise)

4. Transposition Cipher Program • Password cannot contain any repeated letters • Password length ranges from 2 to 7 letters • Main purpose of the key is to number the columns • Text displayed horizontally in box • Number of rows must equal number of letters in the password • Cipher text is read out by columns starting with the column with the smallest number

5. Future of Cryptography • Quantum Cryptography - An unbreakable form of cryptography that exploits quantum theory. Quantum cryptography guarantees the secure exchange of a random series of bits. • Assuming hypothetical eavesdroppers with unlimited computing power can intercept the signal, the laws of physics guarantee (probabilistically) that the secret key exchange will be secure. • Experimental implementations of quantum cryptography have existed since 1990. Transposition Cipher Program and Examples

6. Sources • www.exploratorium.edu/ronh/secret/secret.html • www.qubit.org/oldsite/intros/crypt.html • www.cs.dartmouth.edu/~jford/crypto.html