static void Main(string[] args)
{
string cipherText0 = "UIF RVJDL CSPXO GPY KVNQT PWFS 13 MBAZ EPHT."; // 1
Console.WriteLine("Test Cipher Text: " + CaesarCipher.decrypt(cipherText0, 1));
//string cipherText1 = "KVXUAOGRRDRBGFTPDVWRMCDWTELUAWXILKNZGVXTYHPEMQVHVETIABPSMVHXYIGFMBNLLPOPDAENTAGNLRETMSTIABPHXVAEMSICSLKOGCTXNYTPDXNOJWEGVLRCNWER";
//string cipherText1 = "ASTZHSSJNSBZFPSSJESNTBPZHNLREYUWCFWYUAXSJEGSTHDDCIPCBEVADINCCQYREYUBLFIDVWJOJOKDPOPQFKXHDPTWCASTZHMSOZZZLBZEVASSJDONPHKWRPSOPEVA";
string cipherText1 = "FWURLERNWEAIFLXFNTIEUVCHDIGXMHIEIIOGFUGTEWRNWZTLVEFJTARTMYEREOPFPIFSXVAVYOMYEKFNXMEKPPKFPHJAEJNHNBTCLLVLHHUXECXRLEFWLYIFKOVFNMIO";
Console.WriteLine("CipherText: " + cipherText1);
Console.WriteLine("\nPlain Text: " + VigenereCipher.decrypt(cipherText1, 3));
Console.ReadLine();
}
//Enum.GetName(typeof(pos), i) : get enum name based on value
public static string decrypt(string cipherText, int keyLength)
{
string plainText = string.Empty;
int lengthText = cipherText.Length;
string[] cipherGroup = new string[keyLength];
string cipher1 = string.Empty, cipher2 = string.Empty, cipher3 = string.Empty;
//Sepearate the cipherText into 3 groups based on their modulo
for (int i = 0; i < lengthText; i++)
{
if (i % keyLength == 0)
{
cipher1 += cipherText[i];
}
if (i % keyLength == 1)
{
cipher2 += cipherText[i];
}
if (i % keyLength == 2)
{
cipher3 += cipherText[i];
}
}
Console.WriteLine("Plain 1: " + cipher1);
Console.WriteLine("Plain 2: " + cipher2);
Console.WriteLine("Plain 3: " + cipher3);
//Counted Text and print
Dictionary <int, int> countRepeated1 = countRepeatedKeys(cipher1);
Dictionary <int, int> countRepeated2 = countRepeatedKeys(cipher2);
Dictionary <int, int> countRepeated3 = countRepeatedKeys(cipher3);
Console.WriteLine("-------Counted Repeating Key-----------\n");
Console.WriteLine("Normal English repeated key");
Console.WriteLine("A B C D E F G H I G K L M N O P Q R S T U V W X Y Z");
Console.WriteLine("8 2 3 4 13 2 2 6 7 0 1 4 2 7 8 2 0 6 6 9 3 1 2 0 2 0");
for (int i = 0; i < 26; i++)
{
Console.Write(Enum.GetName(typeof(pos), i) + " ");
}
Console.WriteLine("\ncipher1");
for (int i = 0; i < 26; i++)
{
Console.Write(countRepeated1[i] + " ");
}
Console.WriteLine("\ncipher2");
for (int i = 0; i < 26; i++)
{
Console.Write(countRepeated2[i] + " ");
}
Console.WriteLine("\ncipher3");
for (int i = 0; i < 26; i++)
{
Console.Write(countRepeated3[i] + " ");
}
//Loop through all possible decrypted texts
for (int i = 0; i < 25; i++)
{
for (int j = 0; j < 25; j++)
{
for (int k = 0; k < 25; k++)
{
string plainText1 = CaesarCipher.decrypt(cipher1, i); //P is the highest probability in text1, it should be E in normal English, shift back 11/2
string plainText2 = CaesarCipher.decrypt(cipher2, j); //P is the highest probability in text1, it should be E in normal English, shift back 22
string plainText3 = CaesarCipher.decrypt(cipher3, k); //P is the highest probability in text1, it should be E in normal English, shift back 7 / 15
plainText = string.Empty;
for (int l = 0; l < plainText1.Length; l++)
{
plainText += plainText1[l];
plainText += plainText2[l];
if (l < plainText3.Length) //Clumpsy code
{
plainText += plainText3[l];
}
}
//Console.WriteLine("----" + i + "," + j + "," + k + ":" + plainText);
if (plainText.Contains("THE") || plainText.Contains("AND"))
{
Console.WriteLine("KEY is : " + Enum.GetName(typeof(pos), i) + Enum.GetName(typeof(pos), j) + Enum.GetName(typeof(pos), k));
Console.WriteLine("----" + Enum.GetName(typeof(pos), i) + Enum.GetName(typeof(pos), j) + Enum.GetName(typeof(pos), k) + " : " + i + "," + j + "," + k + ":" + plainText);
Console.ReadKey();
}
/*if (i == 2 && j == 0 && k == 19)
* {
* Console.WriteLine("KEY is : " + Enum.GetName(typeof(pos), i) + Enum.GetName(typeof(pos), j) + Enum.GetName(typeof(pos), k));
* string shortPlainText = string.Empty;
* for (int m = 0; m < 40; m++)
* {
* shortPlainText += plainText[m];
* }
* Console.WriteLine("First 40 words of plainText: " + shortPlainText);
* return plainText;
* }*/
}
}
}
return(plainText);
}
