Railfence Columnar Cipher

This is the combination of Rail fence Cipher with Columnar implementation..

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import java.util.*; public class RFwithColumnar { public static void main(String[] args) { String text = "IF YOU CAN READ THIS YOU ARE GENIUS"; String key = "HACK"; String enc = RFCEncryption(text, key); System.out.println(enc); } public static String RFCEncryption(String text, String keytext) { int[] arrange = arrangeKey(keytext); int key = arrange.length; int lentext = text.length(); int move = 1; int count = 0; String[][] rfp = new String[key][lentext]; // arrange dot fence for (int x = 0; x < rfp.length; x++) { for (int y = 0; y < rfp[x].length; y++) { rfp[x][y] = "."; } } // formatting according fence rails for (int i = 0; i < lentext; i++) { if ((move % 2) != 0) { rfp[count][i] = "" + text.charAt(i); if (count == (key - 1)) { move = 2; count = (key - 2); } else count++; } else if ((move % 2) == 0) { rfp[count][i] = "" + text.charAt(i); if (count == 0) { move = 1; count = 1; } else count--; } } //replace any white space with X or random for (int x = 0; x < rfp.length; x++) { for (int y = 0; y < rfp[x].length; y++) { if (rfp[x][y].equals(" ")) rfp[x][y] = ""+Character.toUpperCase(RandomAlpha()); } } // display System.out.println(); for (int i = 0; i < rfp.length; i++) { for (int u = 0; u < rfp[i].length; u++) { System.out.print(rfp[i][u] + " "); } System.out.println(); } System.out.println(); StringBuilder cb = new StringBuilder(); //encode string from fence for (int x = 0; x < key; x++) { for (int y = 0; y < key; y++) { if (x == arrange[y]) { for (int u = 0; u < lentext; u++) { if (!".".equals(rfp[y][u])) { cb.append(rfp[y][u]); } } } } } return "" + cb; } public static int[] arrangeKey(String key) { //arrange position of grid String[] keys = key.split(""); Arrays.sort(keys); int[] num = new int[key.length()]; for (int x = 0; x < keys.length; x++) { for (int y = 0; y < key.length(); y++) { if (keys[x].equals(key.charAt(y) + "")) { num[y] = x; break; } } } System.out.println(Arrays.toString(num)); return num; } public static char RandomAlpha() { //generate random alpha for null space Random r = new Random(); return (char)(r.nextInt(26) + 'a'); } }