Vigenère cipher

After a long time, I've been doing some coding, well I was teaching.I had to do Vigenère cipher in Java.

First of all, What is "Vigenère cipher"?

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 is a form of polyalphabetic substitution (Wikipedia) 

There are a lot of methods for creating this Encryption method. For those who know how to code with OOP Principles, this code may look like Babies Rusk. 😋

We can code this in two ways.

Method 1

We use the Vigenère Matrix to find the Cipher Text. We will create the Matrix through looping and row will be either plaintext and column will be key string.

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import java.util.*; public class Vigenere { public static void main(String [] args) { Scanner scan = new Scanner (System.in); System.out.print("Enter the message= "); String plain = scan.nextLine(); plain=plain.toUpperCase(); System.out.print("Enter the key= "); String key = scan.nextLine(); key=key.toUpperCase(); char [][] vignerematrix = new char [26][26]; char [] alp = {'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'}; int num = 0; int t = 0; for(int i=0;i<=25;i++) { for (int j=0;j<=25;j++) { num = (i+j)%26; vignerematrix [i][j] = alp[num]; } } int strlen = plain.length(); int keylen = key.length(); char onstr = 'a'; char onkeyey = 'a'; for(int i=0;i<strlen;i++) { onstr = plain.charAt(i); onkeyey = key.charAt(i%keylen); int row=0; int col=0; for(int j=0;j<26;j++) { if(onstr == alp[j]) { row = j; break; } } for(int j=0;j<26;j++) { if(onkeyey == alp[j]) { col = j; break; } } System.out.print(vignerematrix[row][col]); } } }

Method 2

Calculate the Cipher key with adding the Plain text characters and key characters in order and finding the Cipher text through.

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import java.util.*; public class VigenereSimplified { public static void main(String [] args) { Scanner scan = new Scanner (System.in); System.out.print("Enter the message= "); String plain = scan.nextLine(); plain=plain.toUpperCase(); System.out.print("Enter the key= "); String key = scan.nextLine(); key=key.toUpperCase(); char [] alp = {'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'}; String cipherText=""; int cipher=0; for(int i=0;i<plain.length();i++) { cipher = 0; for(int j=0;j<26;j++) { if(plain.charAt(i) == alp[j]) { cipher += j; } if(key.charAt(i%key.length()) == alp[j]) { cipher += j; } } cipherText += alp[cipher%26]; } System.out.println(plain+" + "+key+" = "+cipherText); } }

These are some basic coding styles, which is hard coding.

Hey! There may be more than one solution for one problem.