//https://www.dcode.fr/vigenere-cipher
public string Decrypt(string key, string encMessage)
{
string decryptedString = string.Empty;
int keyDecode = 0;
char[] encMessageArray = encMessage.ToLower().ToCharArray();
char[] keyArray = key.ToLower().ToCharArray();
for (int i = 0; i < encMessageArray.Length; i++)
{
// Loops thru the keyValues
if (keyDecode >= keyArray.Length)
{
keyDecode = 0;
}
int a = IndexData.GetIndexOfCharacter(keyArray[keyDecode]);
int c = IndexData.GetIndexOfCharacterFromCypther(a, encMessageArray[i]);
decryptedString += CyptherData.Alphabet[c];
keyDecode++;
}
return(decryptedString);
}
public string Encrypt(string key, string message)
{
string encryptedString = string.Empty;
char[] messageArray = message.ToLower().ToCharArray();
char[] keyArray = key.ToLower().ToCharArray();
int keyNum = 0;
for (int i = 0; i < messageArray.Length; i++)
{
if (keyNum >= keyArray.Length)
{
keyNum = 0;
}
int keyIndex = IndexData.GetIndexOfCharacter(keyArray[keyNum]);
int messageIndex = IndexData.GetIndexOfCharacter(messageArray[i]);
encryptedString += CyptherData.Cypher[keyIndex, messageIndex];
keyNum++;
}
return(encryptedString);
}
