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  1. <?php
  2.  
  3. // Define the Polynomial class
  4. class Polynomial {
  5.     public $coefficients;
  6.  
  7.     public function __construct($coefficients) {
  8.         $this->coefficients = is_array($coefficients) ? $coefficients : [];
  9.     }
  10.  
  11.     public function order() {
  12.         return count($this->coefficients) - 1;
  13.     }
  14.  
  15.     public function evaluate($x) {
  16.         $result = 0;
  17.         foreach ($this->coefficients as $power => $coefficient) {
  18.             $result += $coefficient * pow($x, $power);
  19.         }
  20.         return $result;
  21.     }
  22. }
  23.  
  24. // Define the LagrangeInterpolation class
  25. class LagrangeInterpolation {
  26.     private $x;
  27.     private $y;
  28.  
  29.     public function __construct($x, $y) {
  30.         $this->x = $x;
  31.         $this->y = $y;
  32.     }
  33.  
  34.     public function evaluate($x) {
  35.         $n = count($this->x);
  36.         $result = 0;
  37.         for ($i = 0; $i < $n; $i++) {
  38.             $term = $this->y[$i];
  39.             for ($j = 0; $j < $n; $j++) {
  40.                 if ($j != $i) {
  41.                     $term *= ($x - $this->x[$j]) / ($this->x[$i] - $this->x[$j]);
  42.                 }
  43.             }
  44.             $result += $term;
  45.         }
  46.         return $result;
  47.     }
  48. }
  49.  
  50. function root_finding_initial_values($f) {
  51.     // Sample coefficients for Polynomial for demonstration
  52.     $poly1 = new Polynomial([1, -1]); // Example polynomial x - 1
  53.     $degree1 = $poly1->order();
  54.  
  55.     if (1 <= $degree1 && $degree1 < 10) {
  56.         $nth_root = $degree1 / 2;
  57.     } elseif (10 <= $degree1 && $degree1 <= 15) {
  58.         $nth_root = $degree1 / 3;
  59.     } else {
  60.         $nth_root = $degree1;
  61.     }
  62.  
  63.     $constant = abs($poly1->evaluate(0));
  64.     $constant_nth_root = pow($constant, 1 / $nth_root);
  65.     $initial_one_false_position = -round($constant_nth_root);
  66.     $initial_two_false_position = round($constant_nth_root);
  67.  
  68.     return [$initial_one_false_position, $initial_two_false_position];
  69. }
  70.  
  71. function hybrid_method($f, $a, $b, $tol=1e-6, $max_iter=100000) {
  72.     $start_time = time();
  73.     $a1 = $a;
  74.     $a2 = $a;
  75.     $b1 = $b;
  76.     $b2 = $b;
  77.     for ($i = 0; $i < $max_iter; $i++) {
  78.         $xT1 = ($b + 2*$a) / 3;
  79.         $xT2 = (2*$b + $a) / 3;
  80.         $fa = $f($a);
  81.         $fb = $f($b);
  82.  
  83.         if ($fb - $fa == 0) {
  84.             throw new Exception("Division by zero in false position calculation");
  85.         }
  86.  
  87.         $xF = $a - ($fa * ($b - $a)) / ($fb - $fa);
  88.         $x = $xT1;
  89.  
  90.         if (abs($f($xT2)) < abs($f($x))) {
  91.             $x = $xT2;
  92.         }
  93.         if (abs($f($xF)) < abs($f($x))) {
  94.             $x = $xF;
  95.         }
  96.         if (abs($f($x)) <= $tol) {
  97.             $end_time = time();
  98.             $execution_time = $end_time - $start_time;
  99.             return [$x, $f($x), $i, $execution_time, $a, $b];
  100.         }
  101.  
  102.         if ($fa * $f($xT1) < 0) {
  103.             $b1 = $xT1;
  104.         } elseif ($f($xT1) * $f($xT2) < 0) {
  105.             $a1 = $xT1;
  106.             $b1 = $xT2;
  107.         } else {
  108.             $a1 = $xT2;
  109.         }
  110.         if ($fa * $f($xF) < 0) {
  111.             $b2 = $xF;
  112.         } else {
  113.             $a2 = $xF;
  114.         }
  115.         $a = max($a1, $a2);
  116.         $b = min($b1, $b2);
  117.     }
  118.     throw new Exception("Hybrid method did not converge within the maximum number of iterations");
  119. }
  120.  
  121. // Generate random text of a specific length
  122. $length = 80;
  123. $random_text = '';
  124. $characters = array_merge(range('a', 'z'), range('A', 'Z'), range(0, 9), str_split('!@#$%^&*()'));
  125. for ($i = 0; $i < $length; $i++) {
  126.     $random_text .= $characters[array_rand($characters)];
  127. }
  128.  
  129. // Encode the plaintext using UTF-8 encoding
  130. $plain_bytes = utf8_encode($random_text);
  131.  
  132. // Convert the bytes to a list of integers representing the individual byte values
  133. $digits = array_map('ord', str_split($plain_bytes));
  134.  
  135. // Randomly select an odd degree between 1 and 9
  136. $degree = rand(1, 9);
  137.  
  138. // Generate randomised polynomial through Lagrange Interpolation
  139. $x = range(1, $degree + 2);  // x values for interpolation
  140. $y = array_slice($digits, 0, $degree + 2);  // y values for interpolation
  141. $poly = new LagrangeInterpolation($x, $y);
  142.  
  143. // Generate scrambled polynomial
  144. $f = function($x) use ($poly, $digits) {
  145.     return $poly->evaluate($x) - $digits[0];
  146. };
  147.  
  148. // Guess initial values using root_finding_initial_values function
  149. list($init_a, $init_b) = root_finding_initial_values($f);
  150.  
  151. try {
  152.     // Apply the Hybrid method
  153.     list($x, $fx, $i, $execution_time, $a, $b) = hybrid_method($f, $init_a, $init_b);
  154.  
  155.     function encrypt_file($file_path, $key, $iv) {
  156.         $plaintext = file_get_contents($file_path);
  157.         $cipher = "aes-256-cfb8";
  158.         $ciphertext = openssl_encrypt($plaintext, $cipher, $key, OPENSSL_RAW_DATA, $iv);
  159.  
  160.         file_put_contents($file_path . '.enc', $ciphertext);
  161.     }
  162.  
  163.     $key = (string) round($x, 0);
  164.     $iv = openssl_random_pseudo_bytes(16);
  165.     $file_path = "Data.txt";
  166.     encrypt_file($file_path, $key, $iv);
  167.     echo "key: " . $key . "\n";
  168.     echo "iv: " . bin2hex($iv); 
  169. } catch (Exception $e) {
  170.     echo 'Error: ' . $e->getMessage();
  171. }
  172.  
  173. ?>
  174.  
Success #stdin #stdout #stderr 0.02s 26488KB
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stdin
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Standard input is empty
stdout
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key: 1
iv: c1b8e4cb4b5302bdc5143a79ec684263
stderr
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PHP Warning:  file_get_contents(Data.txt): failed to open stream: No such file or directory in /home/KREV4i/prog.php on line 156
PHP Warning:  file_put_contents(Data.txt.enc): failed to open stream: Permission denied in /home/KREV4i/prog.php on line 160
https://ideone.com/oQYNC0
language:
PHP (php 7.3.5)
created:
214 days ago
visibility:
public

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