67 lines
2.5 KiB
C#
67 lines
2.5 KiB
C#
using System;
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namespace Chaocipher {
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enum Mode {
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ENCRYPT,
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DECRYPT,
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}
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class Program {
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const string L_ALPHABET = "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
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const string R_ALPHABET = "PTLNBQDEOYSFAVZKGJRIHWXUMC";
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static string Exec(string text, Mode mode, bool showSteps = false) {
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char[] left = L_ALPHABET.ToCharArray();
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char[] right = R_ALPHABET.ToCharArray();
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char[] eText = new char[text.Length];
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char[] temp = new char[26];
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for (int i = 0; i < text.Length; ++i) {
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if (showSteps) Console.WriteLine("{0} {1}", string.Join("", left), string.Join("", right));
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int index = 0;
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if (mode == Mode.ENCRYPT) {
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index = Array.IndexOf(right, text[i]);
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eText[i] = left[index];
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} else {
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index = Array.IndexOf(left, text[i]);
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eText[i] = right[index];
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}
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if (i == text.Length - 1) break;
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// permute left
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for (int j = index; j < 26; ++j) temp[j - index] = left[j];
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for (int j = 0; j < index; ++j) temp[26 - index + j] = left[j];
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var store = temp[1];
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for (int j = 2; j < 14; ++j) temp[j - 1] = temp[j];
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temp[13] = store;
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temp.CopyTo(left, 0);
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// permute right
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for (int j = index; j < 26; ++j) temp[j - index] = right[j];
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for (int j = 0; j < index; ++j) temp[26 - index + j] = right[j];
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store = temp[0];
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for (int j = 1; j < 26; ++j) temp[j - 1] = temp[j];
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temp[25] = store;
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store = temp[2];
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for (int j = 3; j < 14; ++j) temp[j - 1] = temp[j];
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temp[13] = store;
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temp.CopyTo(right, 0);
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}
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return new string(eText);
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}
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static void Main(string[] args) {
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var plainText = "WELLDONEISBETTERTHANWELLSAID";
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Console.WriteLine("The original plaintext is : {0}", plainText);
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Console.WriteLine("\nThe left and right alphabets after each permutation during encryption are :\n");
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var cipherText = Exec(plainText, Mode.ENCRYPT, true);
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Console.WriteLine("\nThe ciphertext is : {0}", cipherText);
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var plainText2 = Exec(cipherText, Mode.DECRYPT);
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Console.WriteLine("\nThe recovered plaintext is : {0}", plainText2);
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}
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}
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}
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