<? // two rot13 ('rotate alphabet 13 places') decryption/encryption functions // rot13 is intended to be a simple encryption method // --- FIRST METHOD --- // // rot 13 using some simple string transalting function rot13_1($string) { // turn the first characters into the second ones $before = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; $after = 'nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM'; // replace and return return strtr($string, $before, $after); } // --- SECOND METHOD --- // // rot13 using some slightly more advanced character shifting function rot13_2($string) { // loop through all the characters for ($n = 0; $n < strlen($string); $n++) { // check if it's at the start of the alphabet if (eregi('[a-mA-M]', $string[$n])) // if so, add characters to shift it thirteen places forward $string[$n] = chr(ord($string[$n]) + 13); // if not else if (eregi('[n-zN-Z]', $string[$n])) // shift it thirteen places back $string[$n] = chr(ord($string[$n]) - 13); } // return the new string return $string; }?>