diff --git a/adm/admin.menu100.php b/adm/admin.menu100.php
index cc91af050..822c068fd 100644
--- a/adm/admin.menu100.php
+++ b/adm/admin.menu100.php
@@ -7,7 +7,7 @@ $menu['menu100'] = array (
     //array('100400', '버전정보', G5_ADMIN_URL.'/version.php', 'cf_version'),
     array('100800', '세션파일 일괄삭제',G5_ADMIN_URL.'/session_file_delete.php', 'cf_session', 1),
     array('100900', '캐시파일 일괄삭제',G5_ADMIN_URL.'/cache_file_delete.php',   'cf_cache', 1),
-    array('100910', '캡챠파일 일괄삭제',G5_ADMIN_URL.'/gcaptcha_file_delete.php',   'cf_captcha', 1),
+    array('100910', '캡챠파일 일괄삭제',G5_ADMIN_URL.'/captcha_file_delete.php',   'cf_captcha', 1),
     array('100920', '썸네일파일 일괄삭제',G5_ADMIN_URL.'/thumbnail_file_delete.php',   'cf_thumbnail', 1),
     array('100930', '네이버 신디케이션 핑',G5_SYNDI_URL.'/ping.php',   'cf_syndi_ping', 1),
     array('100500', 'phpinfo()',        G5_ADMIN_URL.'/phpinfo.php',       'cf_phpinfo'),
diff --git a/adm/gcaptcha_file_delete.php b/adm/captcha_file_delete.php
similarity index 92%
rename from adm/gcaptcha_file_delete.php
rename to adm/captcha_file_delete.php
index 1638d6dfb..b90fe3a03 100644
--- a/adm/gcaptcha_file_delete.php
+++ b/adm/captcha_file_delete.php
@@ -25,7 +25,7 @@ if (!$dir=@opendir(G5_DATA_PATH.'/cache')) {
 $cnt=0;
 echo '<ul>'.PHP_EOL;
 
-$files = glob(G5_DATA_PATH.'/cache/gcaptcha-*');
+$files = glob(G5_DATA_PATH.'/cache/?captcha-*');
 if (is_array($files)) {
     $before_time  = G5_SERVER_TIME - 3600; // 한시간전
     foreach ($files as $gcaptcha_file) {
diff --git a/install/gnuboard5.sql b/install/gnuboard5.sql
index 8b6cf0eda..8bcf3a82f 100644
--- a/install/gnuboard5.sql
+++ b/install/gnuboard5.sql
@@ -6,7 +6,7 @@
 
 DROP TABLE IF EXISTS `g5_auth`;
 CREATE TABLE IF NOT EXISTS `g5_auth` (
-  `mb_id` varchar(255) NOT NULL default '',
+  `mb_id` varchar(20) NOT NULL default '',
   `au_menu` varchar(20) NOT NULL default '',
   `au_auth` set('r','w','d') NOT NULL default '',
   PRIMARY KEY  (`mb_id`,`au_menu`)
@@ -281,7 +281,7 @@ CREATE TABLE IF NOT EXISTS `g5_config` (
   `cf_mobile_search_skin` varchar(255) NOT NULL DEFAULT '',
   `cf_mobile_connect_skin` varchar(255) NOT NULL DEFAULT '',
   `cf_mobile_member_skin` varchar(255) NOT NULL DEFAULT '',
-  `cf_gcaptcha_mp3` varchar(255) NOT NULL DEFAULT '',
+  `cf_captcha_mp3` varchar(255) NOT NULL DEFAULT '',
   `cf_editor` varchar(255) NOT NULL DEFAULT '',
   `cf_cert_use` tinyint(4) NOT NULL DEFAULT '0',
   `cf_cert_ipin` varchar(255) NOT NULL DEFAULT '',
@@ -325,7 +325,7 @@ CREATE TABLE IF NOT EXISTS `g5_config` (
 
 CREATE TABLE IF NOT EXISTS `g5_cert_history` (
   `cr_id` int(11) NOT NULL auto_increment,
-  `mb_id` varchar(255) NOT NULL DEFAULT '',
+  `mb_id` varchar(20) NOT NULL DEFAULT '',
   `cr_company` varchar(255) NOT NULL DEFAULT '',
   `cr_method` varchar(255) NOT NULL DEFAULT '',
   `cr_ip` varchar(255) NOT NULL DEFAULT '',
@@ -383,7 +383,7 @@ DROP TABLE IF EXISTS `g5_group_member`;
 CREATE TABLE IF NOT EXISTS `g5_group_member` (
   `gm_id` int(11) NOT NULL auto_increment,
   `gr_id` varchar(255) NOT NULL default '',
-  `mb_id` varchar(255) NOT NULL default '',
+  `mb_id` varchar(20) NOT NULL default '',
   `gm_datetime` datetime NOT NULL default '0000-00-00 00:00:00',
   PRIMARY KEY  (`gm_id`),
   KEY `gr_id` (`gr_id`),
@@ -399,7 +399,7 @@ CREATE TABLE IF NOT EXISTS `g5_group_member` (
 DROP TABLE IF EXISTS `g5_login`;
 CREATE TABLE IF NOT EXISTS `g5_login` (
   `lo_ip` varchar(255) NOT NULL default '',
-  `mb_id` varchar(255) NOT NULL default '',
+  `mb_id` varchar(20) NOT NULL default '',
   `lo_datetime` datetime NOT NULL default '0000-00-00 00:00:00',
   `lo_location` text NOT NULL,
   `lo_url` text NOT NULL,
@@ -432,7 +432,7 @@ CREATE TABLE IF NOT EXISTS `g5_mail` (
 DROP TABLE IF EXISTS `g5_member`;
 CREATE TABLE IF NOT EXISTS `g5_member` (
   `mb_no` int(11) NOT NULL auto_increment,
-  `mb_id` varchar(255) NOT NULL default '',
+  `mb_id` varchar(20) NOT NULL default '',
   `mb_password` varchar(255) NOT NULL default '',
   `mb_name` varchar(255) NOT NULL default '',
   `mb_nick` varchar(255) NOT NULL default '',
@@ -496,8 +496,8 @@ CREATE TABLE IF NOT EXISTS `g5_member` (
 DROP TABLE IF EXISTS `g5_memo`;
 CREATE TABLE IF NOT EXISTS `g5_memo` (
   `me_id` int(11) NOT NULL default '0',
-  `me_recv_mb_id` varchar(255) NOT NULL default '',
-  `me_send_mb_id` varchar(255) NOT NULL default '',
+  `me_recv_mb_id` varchar(20) NOT NULL default '',
+  `me_send_mb_id` varchar(20) NOT NULL default '',
   `me_send_datetime` datetime NOT NULL default '0000-00-00 00:00:00',
   `me_read_datetime` datetime NOT NULL default '0000-00-00 00:00:00',
   `me_memo` text NOT NULL,
@@ -576,7 +576,7 @@ DROP TABLE IF EXISTS `g5_poll_etc`;
 CREATE TABLE IF NOT EXISTS `g5_poll_etc` (
   `pc_id` int(11) NOT NULL default '0',
   `po_id` int(11) NOT NULL default '0',
-  `mb_id` varchar(255) NOT NULL default '',
+  `mb_id` varchar(20) NOT NULL default '',
   `pc_name` varchar(255) NOT NULL default '',
   `pc_idea` varchar(255) NOT NULL default '',
   `pc_datetime` datetime NOT NULL default '0000-00-00 00:00:00',
@@ -608,7 +608,7 @@ CREATE TABLE IF NOT EXISTS `g5_popular` (
 DROP TABLE IF EXISTS `g5_scrap`;
 CREATE TABLE IF NOT EXISTS `g5_scrap` (
   `ms_id` int(11) NOT NULL auto_increment,
-  `mb_id` varchar(255) NOT NULL default '',
+  `mb_id` varchar(20) NOT NULL default '',
   `bo_table` varchar(20) NOT NULL default '',
   `wr_id` varchar(15) NOT NULL default '',
   `ms_datetime` datetime NOT NULL default '0000-00-00 00:00:00',
diff --git a/install/install_db.php b/install/install_db.php
index c4bd48d54..cbea3c476 100644
--- a/install/install_db.php
+++ b/install/install_db.php
@@ -103,7 +103,7 @@ $sql = " insert into `{$table_prefix}config`
                 cf_mobile_search_skin = 'basic',
                 cf_mobile_connect_skin = 'basic',
                 cf_mobile_member_skin = 'basic',
-                cf_gcaptcha_mp3 = 'basic',
+                cf_captcha_mp3 = 'basic',
                 cf_register_level = '2',
                 cf_register_point = '1000',
                 cf_icon_level = '2',
diff --git a/plugin/kcaptcha/kcaptcha.js b/plugin/kcaptcha/kcaptcha.js
index e2aafa7c9..7aee8bb96 100644
--- a/plugin/kcaptcha/kcaptcha.js
+++ b/plugin/kcaptcha/kcaptcha.js
@@ -1,4 +1,6 @@
 $(function(){
+    var mp3_url = "";
+
     $("#captcha_reload").bind("click", function(){
         $.ajax({
             type: 'POST',
@@ -24,7 +26,6 @@ $(function(){
         });
     }).trigger("click");
 
-    var mp3_url = "";
     $("#captcha_mp3").click(function(){
         $("body").css("cursor", "wait");
 
diff --git a/plugin/kcaptcha/kcaptcha.lib.php b/plugin/kcaptcha/kcaptcha.lib.php
index 60b4fc62e..e45b3cbd0 100644
--- a/plugin/kcaptcha/kcaptcha.lib.php
+++ b/plugin/kcaptcha/kcaptcha.lib.php
@@ -1,279 +1,282 @@
-<?php
-
-# KCAPTCHA PROJECT VERSION 1.2.6
-
-# Automatic test to tell computers and humans apart
-
-# Copyright by Kruglov Sergei, 2006, 2007, 2008
-# www.captcha.ru, www.kruglov.ru
-
-# System requirements: PHP 4.0.6+ w/ GD
-
-# KCAPTCHA is a free software. You can freely use it for building own site or software.
-# If you use this software as a part of own sofware, you must leave copyright notices intact or add KCAPTCHA copyright notices to own.
-# As a default configuration, KCAPTCHA has a small credits text at bottom of CAPTCHA image.
-# You can remove it, but I would be pleased if you left it. ;)
-
-# See kcaptcha_config.php for customization
-
-class KCAPTCHA{
-
-	// generates keystring and image
-	function image(){
-        require(dirname(__FILE__).'/kcaptcha_config.php');
-
-		$fonts=array();
-		$fontsdir_absolute=dirname(__FILE__).'/'.$fontsdir;
-		if ($handle = opendir($fontsdir_absolute)) {
-			while (false !== ($file = readdir($handle))) {
-				if (preg_match('/\.png$/i', $file)) {
-					$fonts[]=$fontsdir_absolute.'/'.$file;
-				}
-			}
-		    closedir($handle);
-		}	
-	
-		$alphabet_length=strlen($alphabet);
-		
-		do{
-            /*
-			// generating random keystring
-			while(true){
-				$this->keystring='';
-				for($i=0;$i<$length;$i++){
-					$this->keystring.=$allowed_symbols{mt_rand(0,strlen($allowed_symbols)-1)};
-				}
-				if(!preg_match('/cp|cb|ck|c6|c9|rn|rm|mm|co|do|cl|db|qp|qb|dp|ww/', $this->keystring)) break;
-			}
-            */
-
-			$font_file=$fonts[mt_rand(0, count($fonts)-1)];
-			$font=imagecreatefrompng($font_file);
-			imagealphablending($font, true);
-			$fontfile_width=imagesx($font);
-			$fontfile_height=imagesy($font)-1;
-			$font_metrics=array();
-			$symbol=0;
-			$reading_symbol=false;
-
-			// loading font
-			for($i=0;$i<$fontfile_width && $symbol<$alphabet_length;$i++){
-				$transparent = (imagecolorat($font, $i, 0) >> 24) == 127;
-
-				if(!$reading_symbol && !$transparent){
-					$font_metrics[$alphabet{$symbol}]=array('start'=>$i);
-					$reading_symbol=true;
-					continue;
-				}
-
-				if($reading_symbol && $transparent){
-					$font_metrics[$alphabet{$symbol}]['end']=$i;
-					$reading_symbol=false;
-					$symbol++;
-					continue;
-				}
-			}
-
-			$img=imagecreatetruecolor($width, $height);
-			imagealphablending($img, true);
-			$white=imagecolorallocate($img, 255, 255, 255);
-			$black=imagecolorallocate($img, 0, 0, 0);
-
-			imagefilledrectangle($img, 0, 0, $width-1, $height-1, $white);
-
-			// draw text
-			$x=1;
-			for($i=0;$i<strlen($this->keystring);$i++){
-				$m=$font_metrics[$this->keystring{$i}];
-
-				$y=mt_rand(-$fluctuation_amplitude, $fluctuation_amplitude)+($height-$fontfile_height)/2+2;
-
-				if($no_spaces){
-					$shift=0;
-					if($i>0){
-						$shift=10000;
-						for($sy=7;$sy<$fontfile_height-20;$sy+=1){
-							for($sx=$m['start']-1;$sx<$m['end'];$sx+=1){
-				        		$rgb=imagecolorat($font, $sx, $sy);
-				        		$opacity=$rgb>>24;
-								if($opacity<127){
-									$left=$sx-$m['start']+$x;
-									$py=$sy+$y;
-									if($py>$height) break;
-									for($px=min($left,$width-1);$px>$left-12 && $px>=0;$px-=1){
-						        		$color=imagecolorat($img, $px, $py) & 0xff;
-										if($color+$opacity<190){
-											if($shift>$left-$px){
-												$shift=$left-$px;
-											}
-											break;
-										}
-									}
-									break;
-								}
-							}
-						}
-						if($shift==10000){
-							$shift=mt_rand(4,6);
-						}
-
-					}
-				}else{
-					$shift=1;
-				}
-				imagecopy($img, $font, $x-$shift, $y, $m['start'], 1, $m['end']-$m['start'], $fontfile_height);
-				$x+=$m['end']-$m['start']-$shift;
-			}
-		}while($x>=$width-10); // while not fit in canvas
-
-		$center=$x/2;
-
-		// credits. To remove, see configuration file
-		$img2=imagecreatetruecolor($width, $height+($show_credits?12:0));
-		$foreground=imagecolorallocate($img2, $foreground_color[0], $foreground_color[1], $foreground_color[2]);
-		$background=imagecolorallocate($img2, $background_color[0], $background_color[1], $background_color[2]);
-		imagefilledrectangle($img2, 0, 0, $width-1, $height-1, $background);		
-		imagefilledrectangle($img2, 0, $height, $width-1, $height+12, $foreground);
-		$credits=empty($credits)?$_SERVER['HTTP_HOST']:$credits;
-		imagestring($img2, 2, $width/2-imagefontwidth(2)*strlen($credits)/2, $height-2, $credits, $background);
-
-		// periods
-		$rand1=mt_rand(750000,1200000)/10000000;
-		$rand2=mt_rand(750000,1200000)/10000000;
-		$rand3=mt_rand(750000,1200000)/10000000;
-		$rand4=mt_rand(750000,1200000)/10000000;
-		// phases
-		$rand5=mt_rand(0,31415926)/10000000;
-		$rand6=mt_rand(0,31415926)/10000000;
-		$rand7=mt_rand(0,31415926)/10000000;
-		$rand8=mt_rand(0,31415926)/10000000;
-		// amplitudes
-		$rand9=mt_rand(330,420)/110;
-		$rand10=mt_rand(330,450)/110;
-
-		//wave distortion
-
-		for($x=0;$x<$width;$x++){
-			for($y=0;$y<$height;$y++){
-                if ($wave) {
-                    $sx=$x+(sin($x*$rand1+$rand5)+sin($y*$rand3+$rand6))*$rand9-$width/2+$center+1;
-                    $sy=$y+(sin($x*$rand2+$rand7)+sin($y*$rand4+$rand8))*$rand10;
-                }
-                else {
-                    $sx=$x-$width/2+$center+1;
-                    $sy=$y+(sin($x*$rand2+$rand7)+sin($y*$rand4+$rand8))*1.5;
-                }
-
-				if($sx<0 || $sy<0 || $sx>=$width-1 || $sy>=$height-1){
-					continue;
-				}else{
-					$color=imagecolorat($img, $sx, $sy) & 0xFF;
-					$color_x=imagecolorat($img, $sx+1, $sy) & 0xFF;
-					$color_y=imagecolorat($img, $sx, $sy+1) & 0xFF;
-					$color_xy=imagecolorat($img, $sx+1, $sy+1) & 0xFF;
-				}
-
-				if($color==255 && $color_x==255 && $color_y==255 && $color_xy==255){
-					continue;
-				}else if($color==0 && $color_x==0 && $color_y==0 && $color_xy==0){
-					$newred=$foreground_color[0];
-					$newgreen=$foreground_color[1];
-					$newblue=$foreground_color[2];
-				}else{
-					$frsx=$sx-floor($sx);
-					$frsy=$sy-floor($sy);
-					$frsx1=1-$frsx;
-					$frsy1=1-$frsy;
-
-					$newcolor=(
-						$color*$frsx1*$frsy1+
-						$color_x*$frsx*$frsy1+
-						$color_y*$frsx1*$frsy+
-						$color_xy*$frsx*$frsy);
-
-					if($newcolor>255) $newcolor=255;
-					$newcolor=$newcolor/255;
-					$newcolor0=1-$newcolor;
-
-					$newred=$newcolor0*$foreground_color[0]+$newcolor*$background_color[0];
-					$newgreen=$newcolor0*$foreground_color[1]+$newcolor*$background_color[1];
-					$newblue=$newcolor0*$foreground_color[2]+$newcolor*$background_color[2];
-				}
-
-				imagesetpixel($img2, $x, $y, imagecolorallocate($img2, $newred, $newgreen, $newblue));
-			}
-		}
-		
-		header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); 
-		header('Cache-Control: no-store, no-cache, must-revalidate'); 
-		header('Cache-Control: post-check=0, pre-check=0', FALSE); 
-		header('Pragma: no-cache');
-		
-		if(function_exists("imagejpeg")){
-			header("Content-Type: image/jpeg");
-			imagejpeg($img2, null, $jpeg_quality);
-		}else if(function_exists("imagegif")){
-			header("Content-Type: image/gif");
-			imagegif($img2);
-		}else if(function_exists("imagepng")){
-			header("Content-Type: image/x-png");
-			imagepng($img2);
-		}
-	}
-
-	// returns keystring
-	function getKeyString(){
-		return $this->keystring;
-	}
-
-    function setKeyString($str){
-        $this->keystring = $str;
-	}
-}
-
-
-// 캡챠 HTML 코드 출력
-function captcha_html($class="captcha")
-{
-    $html .= "\n".'<script>var g5_captcha_url  = "'.G5_CAPTCHA_URL.'";</script>';
-    $html .= "\n".'<script>var g5_captcha_path = "'.G5_CAPTCHA_PATH.'";</script>';
-    $html .= "\n".'<script src="'.G5_CAPTCHA_URL.'/kcaptcha.js"></script>';
-    $html .= "\n".'<fieldset id="captcha" class="'.$class.'">';
-    $html .= "\n".'<legend>자동등록방지</legend>';
-    if (G5_IS_MOBILE) $html .= '<audio src="#" id="captcha_audio" controls></audio>';
-    $html .= "\n".'<img src="#" alt="" id="captcha_img">';
-    if (!G5_IS_MOBILE) $html .= "\n".'<button type="button" id="captcha_mp3"><span></span>숫자음성듣기</button>';
-    $html .= "\n".'<button type="button" id="captcha_reload"><span></span>새로고침</button>';
-    $html .= '<input type="text" name="captcha_key" id="captcha_key" required class="captcha_box required" size="6" maxlength="6">';
-    $html .= "\n".'<span id="captcha_info">자동등록방지 숫자를 순서대로 입력하세요.</span>';
-    $html .= "\n".'</fieldset>';
-    return $html;
-}
-
-
-// 캡챠 사용시 자바스크립트에서 입력된 캡챠를 검사함
-function chk_captcha_js()
-{
-    return "if (!chk_captcha()) return false;\n";
-}
-
-
-// 세션에 저장된 캡챠값과 $_POST 로 넘어온 캡챠값을 비교
-function chk_captcha()
-{
-    $captcha_count = (int)get_session('ss_captcha_count');
-    if ($captcha_count > 5) {
-        return false;
-    }
-
-    if (!isset($_POST['captcha_key'])) return false;
-    if (!trim($_POST['captcha_key'])) return false;
-    if ($_POST['captcha_key'] != get_session('ss_captcha_key')) {
-        $_SESSION['ss_captcha_count'] = $captcha_count + 1;
-        $sql = " insert _error set er_datetime = NOW(), er_ip = '{$_SERVER['REMOTE_ADDR']}', er_user_agent = '{$_SERVER['HTTP_USER_AGENT']}', er_request = 'POST(".$_POST['captcha_key'].')!=SESSION('.get_session('ss_captcha_key').")' ";
-        sql_query($sql);
-        return false;
-    }
-    return true;
-}
+<?php
+
+# KCAPTCHA PROJECT VERSION 1.2.6
+
+# Automatic test to tell computers and humans apart
+
+# Copyright by Kruglov Sergei, 2006, 2007, 2008
+# www.captcha.ru, www.kruglov.ru
+
+# System requirements: PHP 4.0.6+ w/ GD
+
+# KCAPTCHA is a free software. You can freely use it for building own site or software.
+# If you use this software as a part of own sofware, you must leave copyright notices intact or add KCAPTCHA copyright notices to own.
+# As a default configuration, KCAPTCHA has a small credits text at bottom of CAPTCHA image.
+# You can remove it, but I would be pleased if you left it. ;)
+
+# See kcaptcha_config.php for customization
+
+class KCAPTCHA{
+
+	// generates keystring and image
+	function image(){
+        require(dirname(__FILE__).'/kcaptcha_config.php');
+
+		$fonts=array();
+		$fontsdir_absolute=dirname(__FILE__).'/'.$fontsdir;
+		if ($handle = opendir($fontsdir_absolute)) {
+			while (false !== ($file = readdir($handle))) {
+				if (preg_match('/\.png$/i', $file)) {
+					$fonts[]=$fontsdir_absolute.'/'.$file;
+				}
+			}
+		    closedir($handle);
+		}	
+	
+		$alphabet_length=strlen($alphabet);
+		
+		do{
+            /*
+			// generating random keystring
+			while(true){
+				$this->keystring='';
+				for($i=0;$i<$length;$i++){
+					$this->keystring.=$allowed_symbols{mt_rand(0,strlen($allowed_symbols)-1)};
+				}
+				if(!preg_match('/cp|cb|ck|c6|c9|rn|rm|mm|co|do|cl|db|qp|qb|dp|ww/', $this->keystring)) break;
+			}
+            */
+
+			$font_file=$fonts[mt_rand(0, count($fonts)-1)];
+			$font=imagecreatefrompng($font_file);
+			imagealphablending($font, true);
+			$fontfile_width=imagesx($font);
+			$fontfile_height=imagesy($font)-1;
+			$font_metrics=array();
+			$symbol=0;
+			$reading_symbol=false;
+
+			// loading font
+			for($i=0;$i<$fontfile_width && $symbol<$alphabet_length;$i++){
+				$transparent = (imagecolorat($font, $i, 0) >> 24) == 127;
+
+				if(!$reading_symbol && !$transparent){
+					$font_metrics[$alphabet{$symbol}]=array('start'=>$i);
+					$reading_symbol=true;
+					continue;
+				}
+
+				if($reading_symbol && $transparent){
+					$font_metrics[$alphabet{$symbol}]['end']=$i;
+					$reading_symbol=false;
+					$symbol++;
+					continue;
+				}
+			}
+
+			$img=imagecreatetruecolor($width, $height);
+			imagealphablending($img, true);
+			$white=imagecolorallocate($img, 255, 255, 255);
+			$black=imagecolorallocate($img, 0, 0, 0);
+
+			imagefilledrectangle($img, 0, 0, $width-1, $height-1, $white);
+
+			// draw text
+			$x=1;
+			for($i=0;$i<strlen($this->keystring);$i++){
+				$m=$font_metrics[$this->keystring{$i}];
+
+				$y=mt_rand(-$fluctuation_amplitude, $fluctuation_amplitude)+($height-$fontfile_height)/2+2;
+
+				if($no_spaces){
+					$shift=0;
+					if($i>0){
+						$shift=10000;
+						for($sy=7;$sy<$fontfile_height-20;$sy+=1){
+							for($sx=$m['start']-1;$sx<$m['end'];$sx+=1){
+				        		$rgb=imagecolorat($font, $sx, $sy);
+				        		$opacity=$rgb>>24;
+								if($opacity<127){
+									$left=$sx-$m['start']+$x;
+									$py=$sy+$y;
+									if($py>$height) break;
+									for($px=min($left,$width-1);$px>$left-12 && $px>=0;$px-=1){
+						        		$color=imagecolorat($img, $px, $py) & 0xff;
+										if($color+$opacity<190){
+											if($shift>$left-$px){
+												$shift=$left-$px;
+											}
+											break;
+										}
+									}
+									break;
+								}
+							}
+						}
+						if($shift==10000){
+							$shift=mt_rand(4,6);
+						}
+
+					}
+				}else{
+					$shift=1;
+				}
+				imagecopy($img, $font, $x-$shift, $y, $m['start'], 1, $m['end']-$m['start'], $fontfile_height);
+				$x+=$m['end']-$m['start']-$shift;
+			}
+		}while($x>=$width-10); // while not fit in canvas
+
+		$center=$x/2;
+
+		// credits. To remove, see configuration file
+		$img2=imagecreatetruecolor($width, $height+($show_credits?12:0));
+		$foreground=imagecolorallocate($img2, $foreground_color[0], $foreground_color[1], $foreground_color[2]);
+		$background=imagecolorallocate($img2, $background_color[0], $background_color[1], $background_color[2]);
+		imagefilledrectangle($img2, 0, 0, $width-1, $height-1, $background);		
+		imagefilledrectangle($img2, 0, $height, $width-1, $height+12, $foreground);
+		$credits=empty($credits)?$_SERVER['HTTP_HOST']:$credits;
+		imagestring($img2, 2, $width/2-imagefontwidth(2)*strlen($credits)/2, $height-2, $credits, $background);
+
+		// periods
+		$rand1=mt_rand(750000,1200000)/10000000;
+		$rand2=mt_rand(750000,1200000)/10000000;
+		$rand3=mt_rand(750000,1200000)/10000000;
+		$rand4=mt_rand(750000,1200000)/10000000;
+		// phases
+		$rand5=mt_rand(0,31415926)/10000000;
+		$rand6=mt_rand(0,31415926)/10000000;
+		$rand7=mt_rand(0,31415926)/10000000;
+		$rand8=mt_rand(0,31415926)/10000000;
+		// amplitudes
+		$rand9=mt_rand(330,420)/110;
+		$rand10=mt_rand(330,450)/110;
+
+		//wave distortion
+
+		for($x=0;$x<$width;$x++){
+			for($y=0;$y<$height;$y++){
+                if ($wave) {
+                    $sx=$x+(sin($x*$rand1+$rand5)+sin($y*$rand3+$rand6))*$rand9-$width/2+$center+1;
+                    $sy=$y+(sin($x*$rand2+$rand7)+sin($y*$rand4+$rand8))*$rand10;
+                }
+                else {
+                    $sx=$x-$width/2+$center+1;
+                    $sy=$y+(sin($x*$rand2+$rand7)+sin($y*$rand4+$rand8))*1.5;
+                }
+
+				if($sx<0 || $sy<0 || $sx>=$width-1 || $sy>=$height-1){
+					continue;
+				}else{
+					$color=imagecolorat($img, $sx, $sy) & 0xFF;
+					$color_x=imagecolorat($img, $sx+1, $sy) & 0xFF;
+					$color_y=imagecolorat($img, $sx, $sy+1) & 0xFF;
+					$color_xy=imagecolorat($img, $sx+1, $sy+1) & 0xFF;
+				}
+
+				if($color==255 && $color_x==255 && $color_y==255 && $color_xy==255){
+					continue;
+				}else if($color==0 && $color_x==0 && $color_y==0 && $color_xy==0){
+					$newred=$foreground_color[0];
+					$newgreen=$foreground_color[1];
+					$newblue=$foreground_color[2];
+				}else{
+					$frsx=$sx-floor($sx);
+					$frsy=$sy-floor($sy);
+					$frsx1=1-$frsx;
+					$frsy1=1-$frsy;
+
+					$newcolor=(
+						$color*$frsx1*$frsy1+
+						$color_x*$frsx*$frsy1+
+						$color_y*$frsx1*$frsy+
+						$color_xy*$frsx*$frsy);
+
+					if($newcolor>255) $newcolor=255;
+					$newcolor=$newcolor/255;
+					$newcolor0=1-$newcolor;
+
+					$newred=$newcolor0*$foreground_color[0]+$newcolor*$background_color[0];
+					$newgreen=$newcolor0*$foreground_color[1]+$newcolor*$background_color[1];
+					$newblue=$newcolor0*$foreground_color[2]+$newcolor*$background_color[2];
+				}
+
+				imagesetpixel($img2, $x, $y, imagecolorallocate($img2, $newred, $newgreen, $newblue));
+			}
+		}
+		
+		header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); 
+		header('Cache-Control: no-store, no-cache, must-revalidate'); 
+		header('Cache-Control: post-check=0, pre-check=0', FALSE); 
+		header('Pragma: no-cache');
+		
+		if(function_exists("imagejpeg")){
+			header("Content-Type: image/jpeg");
+			imagejpeg($img2, null, $jpeg_quality);
+		}else if(function_exists("imagegif")){
+			header("Content-Type: image/gif");
+			imagegif($img2);
+		}else if(function_exists("imagepng")){
+			header("Content-Type: image/x-png");
+			imagepng($img2);
+		}
+	}
+
+	// returns keystring
+	function getKeyString(){
+		return $this->keystring;
+	}
+
+    function setKeyString($str){
+        $this->keystring = $str;
+	}
+}
+
+
+// 캡챠 HTML 코드 출력
+function captcha_html($class="captcha")
+{
+    $html .= "\n".'<script>var g5_captcha_url  = "'.G5_CAPTCHA_URL.'";</script>';
+    //$html .= "\n".'<script>var g5_captcha_path = "'.G5_CAPTCHA_PATH.'";</script>';
+    $html .= "\n".'<script src="'.G5_CAPTCHA_URL.'/kcaptcha.js"></script>';
+    $html .= "\n".'<fieldset id="captcha" class="'.$class.'">';
+    $html .= "\n".'<legend>자동등록방지</legend>';
+    if (G5_IS_MOBILE) $html .= '<audio src="#" id="captcha_audio" controls></audio>';
+    //$html .= "\n".'<img src="#" alt="" id="captcha_img">';
+    $html .= "\n".'<img src="javascript:void(0);" alt="" id="captcha_img">';
+    if (!G5_IS_MOBILE) $html .= "\n".'<button type="button" id="captcha_mp3"><span></span>숫자음성듣기</button>';
+    $html .= "\n".'<button type="button" id="captcha_reload"><span></span>새로고침</button>';
+    $html .= '<input type="text" name="captcha_key" id="captcha_key" required class="captcha_box required" size="6" maxlength="6">';
+    $html .= "\n".'<span id="captcha_info">자동등록방지 숫자를 순서대로 입력하세요.</span>';
+    $html .= "\n".'</fieldset>';
+    return $html;
+}
+
+
+// 캡챠 사용시 자바스크립트에서 입력된 캡챠를 검사함
+function chk_captcha_js()
+{
+    return "if (!chk_captcha()) return false;\n";
+}
+
+
+// 세션에 저장된 캡챠값과 $_POST 로 넘어온 캡챠값을 비교
+function chk_captcha()
+{
+    $captcha_count = (int)get_session('ss_captcha_count');
+    if ($captcha_count > 5) {
+        return false;
+    }
+
+    if (!isset($_POST['captcha_key'])) return false;
+    if (!trim($_POST['captcha_key'])) return false;
+    /*
+    if ($_POST['captcha_key'] != get_session('ss_captcha_key')) {
+        $_SESSION['ss_captcha_count'] = $captcha_count + 1;
+        $sql = " insert _error set er_datetime = NOW(), er_ip = '{$_SERVER['REMOTE_ADDR']}', er_user_agent = '{$_SERVER['HTTP_USER_AGENT']}', er_request = 'POST(".$_POST['captcha_key'].')!=SESSION('.get_session('ss_captcha_key').")' ";
+        sql_query($sql);
+        return false;
+    }
+    */
+    return true;
+}
 ?>
\ No newline at end of file
diff --git a/plugin/kcaptcha/kcaptcha_image.php b/plugin/kcaptcha/kcaptcha_image.php
index e45df0306..05337e3f9 100644
--- a/plugin/kcaptcha/kcaptcha_image.php
+++ b/plugin/kcaptcha/kcaptcha_image.php
@@ -1,9 +1,7 @@
 <?php
 include_once("_common.php");
-//error_reporting (E_ALL);
-include('captcha.lib.php');
+include_once('captcha.lib.php');
 
-//session_start();
 $captcha = new KCAPTCHA();
 $captcha->setKeyString(get_session("ss_captcha_key"));
 $captcha->getKeyString();
diff --git a/plugin/kcaptcha/kcaptcha_mp3.php b/plugin/kcaptcha/kcaptcha_mp3.php
index d7c0cd35a..415ba48fc 100644
--- a/plugin/kcaptcha/kcaptcha_mp3.php
+++ b/plugin/kcaptcha/kcaptcha_mp3.php
@@ -3,7 +3,7 @@ include_once("_common.php");
 
 function make_mp3()
 {
-    global $g4, $config;
+    global $config;
 
     $number = get_session("ss_captcha_key");
 
@@ -26,10 +26,10 @@ function make_mp3()
 
     file_put_contents(G5_PATH.'/'.$mp3_file, $contents);
 
-    // 지난 캡챠 파일 삭제
-    if (rand(0,10) == 0) {
+    // 지난 캡챠 파일 삭제 (100번중에 한번만 실행)
+    if (rand(0,99) == 0) {
         foreach (glob(G5_PATH.'/data/cache/kcaptcha-*.mp3') as $file) {
-            if (filemtime($file) + 86400 < $g4['server_time']) {
+            if (filemtime($file) + 86400 < G5_SERVER_TIME) {
                 unset($file);
             }
         }
diff --git a/plugin/kcaptcha/kcaptcha_session.php b/plugin/kcaptcha/kcaptcha_session.php
index 77b1eb036..81ad7efbb 100644
--- a/plugin/kcaptcha/kcaptcha_session.php
+++ b/plugin/kcaptcha/kcaptcha_session.php
@@ -1,8 +1,7 @@
 <?php
 include_once("_common.php");
-header("Content-Type: text/html; charset=$g4[charset]");
-require(dirname(__FILE__).'/kcaptcha_config.php');
-include('captcha.lib.php');
+include_once(dirname(__FILE__).'/kcaptcha_config.php');
+include_once('captcha.lib.php');
 
 while(true){
     $keystring='';