derek121 / mrvigenere

Implementation of the Vigenère cipher

Mr. Vigenère

Implementation of the Vigenère cipher in Go.

About

As described at Wikipedia:

The Vigenère cipher is a method of encrypting alphabetic text by using a series of interwoven Caesar ciphers, based on the letters of a keyword. It employs a form of polyalphabetic substitution

Example

$ go run main.go --usage
2019/10/02 09:15:10 usage args: {{--encode|--decode} key message} | --printtable | --usage
$
$ go run main.go --encode LEMON ATTACKATDAWN
LXFOPVEFRNHR
$ go run main.go --decode LEMON LXFOPVEFRNHR
ATTACKATDAWN
$
$ go run main.go --printtable
 |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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 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 
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 
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 
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