Class used to encrypt and decrypt a text string using Vigenere square */ public class Vigenere { private int numChars; private char[][] vigSquare; private String key; /** * Constructor a Vigenere object and create the square */ public Vigenere (int numChs, String akey) { // add code } /** * Create the Vigenere square matrix */ private void createVigSquare() { // add code } /** * Using the key, encode the message and return the encoded message */ public String encrypt (String message) { // add code } /** * Return the column index of the character, ch, in the message to be encoded */ private int getColIndex (char ch) { // add code } /** * Return the row index of the key character in the Vigenere square */ private int getRowIndex (char keyCh) { // add code } /** * Decrypt the plaintext string using the key and vigSquare * The key characters are the 'row' index and the ciphertext * characters are in the matrix at vigSquare[row][column] * The plaintext characters are the column index */ public String decrypt (String text) { // add code } /** * Returns the plaintext character corresponding to the ciphertext * character 'ch' located in the vigSquare[rowIndex][colIndex] */ private char getPlainTextChar (int rowIndex, char ch) { // add code } }