diff --git a/common_config.php b/common_config.php
index 63ba85e..1be302e 100644
--- a/common_config.php
+++ b/common_config.php
@@ -17,7 +17,7 @@ const VERSION = '1.1'; // Script version
 const DBVERSION = 8; // Database layout version
 const REQUIRE_APPROVAL = false; // require admin approval of new sites? true/false
 const CANONICAL_URL = 'https://onions.danwin1210.de'; // our preferred domain for search engines
-const CAPTCHA = 0; // Captcha difficulty (0=off, 1=simple, 2=moderate, 3=extreme)
+const CAPTCHA = 0; // Captcha difficulty (0=off, 1=simple, 2=moderate, 3=hard, 4=extreme)
 // Language selection
 const LANGUAGES = [
 	'cs' => ['name' => 'čeština', 'locale' => 'cs_CZ', 'flag' => '🇨🇿', 'show_in_menu' => true, 'dir' => 'ltr'],
diff --git a/www/index.php b/www/index.php
index 2778c2a..cde0a21 100644
--- a/www/index.php
+++ b/www/index.php
@@ -536,6 +536,45 @@ function send_captcha(): void
 			imagesetpixel($im, mt_rand(0, 55), mt_rand(0, 24), $dots);
 		}
 		echo ' <img width="55" height="24" alt="'._('captcha image').'" src="data:image/gif;base64,';
+	}elseif(CAPTCHA === 3){
+		$im = imagecreatetruecolor(55, 24);
+		$bg = imagecolorallocatealpha($im, 0, 0, 0, 127);
+		$fg = imagecolorallocate($im, 255, 255, 255);
+		$cc = imagecolorallocate($im, 200, 200, 200);
+		$cb = imagecolorallocatealpha($im, 0, 0, 0, 127);
+		imagefill($im, 0, 0, $bg);
+		$line = imagecolorallocate($im, 255, 255, 255);
+		$deg = (mt_rand(0,1)*2-1)*mt_rand(10, 20);
+
+		$background = imagecreatetruecolor(120, 80);
+		imagefill($background, 0, 0, $cb);
+
+		for ($i=0; $i<20; ++$i) {
+			$char = imagecreatetruecolor(12, 16);
+			imagestring($char, 5, 2, 2, $captchachars[mt_rand(0, $length)], $cc);
+			$char = imagerotate($char, (mt_rand(0,1)*2-1)*mt_rand(10, 20), $cb);
+			$char = imagescale($char, 24, 32);
+			imagefilter($char, IMG_FILTER_SMOOTH, 0.6);
+			imagecopy($background, $char, rand(0, 100), rand(0, 60), 0, 0, 24, 32);
+		}
+
+		imagestring($im, 5, 5, 5, $code, $fg);
+		$im = imagescale($im, 110, 48);
+		imagefilter($im, IMG_FILTER_SMOOTH, 0.5);
+		imagefilter($im, IMG_FILTER_GAUSSIAN_BLUR);
+		$im = imagerotate($im, $deg, $bg);
+		$im = imagecrop($im, array('x'=>0, 'y'=>0, 'width'=>120, 'height'=>80));
+		imagecopy($background, $im, 0, 0, 0, 0, 110, 80);
+		imagedestroy($im);
+		$im = $background;
+
+		for($i=0; $i<1000; ++$i){
+			$c = mt_rand(100,230);
+			$dots = imagecolorallocate($im, $c, $c, $c);
+			imagesetpixel($im, mt_rand(0, 120), mt_rand(0, 80), $dots);
+		}
+		imagedestroy($char);
+		echo '<img width="120" height="80" src="data:image/png;base64,';
 	}else{
 		$im = imagecreatetruecolor(150, 200);
 		$bg = imagecolorallocate($im, 0, 0, 0);