Vigenere Table


Description


Use the table below to decipher any sequential alphabet substitution. All 26 possibilities are presented in the 23 rows of substitution values. You can also use it for Vigenere ciphers!

Key Word Letters

	   A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

	 A A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 

	 B B C D E F G H I J K L M N O P Q R S T U V W X Y Z A

	 C C D E F G H I J K L M N O P Q R S T U V W X Y Z A B 

	 D D E F G H I J K L M N O P Q R S T U V W X Y Z A B C

	 E E F G H I J K L M N O P Q R S T U V W X Y Z A B C D 

	 F F G H I J K L M N O P Q R S T U V W X Y Z A B C D E

	 G G H I J K L M N O P Q R S T U V W X Y Z A B C D E F

	 H H I J K L M N O P Q R S T U V W X Y Z A B C D E F G

M	I I J K L M N O P Q R S T U V W X Y Z A B C D E F G H

e	J J K L M N O P Q R S T U V W X Y Z A B C D E F G H I

s	K K L M N O P Q R S T U V W X Y Z A B C D E F G H I J

s	L L M N O P Q R S T U V W X Y Z A B C D E F G H I J K

a	M M N O P Q R S T U V W X Y Z A B C D E F G H I J K L

g	N N O P Q R S T U V W X Y Z A B C D E F G H I J K L M

e	O O P Q R S T U V W X Y Z A B C D E F G H I J K L M N

	 P P Q R S T U V W X Y Z A B C D E F G H I J K L M N O

L	Q Q R S T U V W X Y Z A B C D E F G H I J K L M N O P

e	R R S T U V W X Y Z A B C D E F G H I J K L M N O P Q

t	S S T U V W X Y Z A B C D E F G H I J K L M N O P Q R

t	T T U V W X Y Z A B C D E F G H I J K L M N O P Q R S

e	U U V W X Y Z A B C D E F G H I J K L M N O P Q R S T

r	V V W X Y Z A B C D E F G H I J K L M N O P Q R S T U

s	W W X Y Z A B C D E F G H I J K L M N O P Q R S T U V

	 X X Y Z A B C D E F G H I J K L M N O P Q R S T U V W 

	 Y Y Z A B C D E F G H I J K L M N O P Q R S T U V W X

	 Z Z A B C D E F G H I J K L M N O P Q R S T U V W X Y


Simple Alphabet Substitution

The first row represents no substitution at all, A = A, B = B, and so on. The second row, starting with "B", is offset by 1 letter. Thus, A = B, B = C, C = D, and so on. For example, if I wrote out the encrypted word "EBE" it would be "DAD" in the second row (offset by one letter). Use this chart to quickly check for patterns that emerge from sequential alphabet substitution deciphering. This decryption key does not include punctuation. Be sure to take that into account when decoding! Ciphers with punctuation are more difficult than A-Z.

Vigenere Method

The Vigenere method is very difficult to break. A key word is usually used to encipher the message. A message is written out with the key word written above it (repeatedly). Look at the example below to see how to encipher messages using the Vigenere table from the previous page:

Key Word: CASH
Message: This is cool.

Enciphering


Key Word Letters:		CASH CA SHCA
Message Letters:		THIS IS COOL
Notice how the key word cash is written over the top of the message. Then correlate the key word letter with the message letter on the Vigenere table. Following the key word column "C" down to the message letter row "T" you find the enciphered letter "V." See if you can finish the enciphering of the message below:

Key Word Letters:		CASH CA SHCA
Message Letters:		THIS IS COOL
Enciphered Letters:		VHAZ K

Making the Cipher Even Tougher!

To make the enciphered message even more difficult use other enciphering methods. For example, once you encipher the word "This" with the key word "Cash," as seen above, you get the enciphered word "vhaz." Encipher "vhaz" into Pig Latin and you get "azvhay." Then you could encipher "azvhay" into a backwards code as "yahvza." In order to decipher this example you would have to write the code backwards (to the original order), decipher the Pig Latin format changes, and use the key word "Cash" and the Vigenere table to correlate key letters and enciphered letters with the message letters! Needless to say, this system of enciphering wasn't broken for a long period of time!!!

The Autoclave Cipher

The autoclave cipher is a variation of the Vigenere cipher, making use of the same table found on the previous page. A key letter is used instead of a key word. For example, you may choose "R" as your key letter. As you encipher your message the enciphered letter becomes the next key letter! Look at the example below to see how it works:

Key Letter:			RVCG Y
Message Letters:		THIS IS COOL
Enciphered Letters:		VCGY
Notice how the key letter "R" correlates with the message letter to give you the enciphered letter "V." "V" is used as the first enciphered letter of the enciphered message and serves as the next key letter. Then "C," the next enciphered letter, becomes the next key letter, etc...