diff --git a/adm/config_form.php b/adm/config_form.php
index fc1af2fda..32a180bb9 100644
--- a/adm/config_form.php
+++ b/adm/config_form.php
@@ -409,6 +409,11 @@ if (!isset($config['cf_cert_kg_mid'])) {
             ADD COLUMN `cf_cert_kg_mid` VARCHAR(255) NOT NULL DEFAULT '' AFTER `cf_cert_kg_cd`; ";
     sql_query($sql, false);
 }
+if (!isset($config['cf_cert_use_seed'])) {
+    $sql = "ALTER TABLE `{$g5['config_table']}` 
+            ADD COLUMN `cf_cert_use_seed` TINYINT(4) NOT NULL DEFAULT '0' AFTER `cf_cert_kg_mid`; ";
+    sql_query($sql, false);
+}
 if (!$config['cf_faq_skin']) {
     $config['cf_faq_skin'] = "basic";
 }
@@ -1003,6 +1008,16 @@ if ($config['cf_sms_use'] && $config['cf_icode_id'] && $config['cf_icode_pw']) {
                             </select>
                         </td>
                     </tr>
+                    <tr>
+                        <th scope="row" class="cf_cert_service"><label for="cf_cert_use_seed">통합인증 암호화 적용</label></th>
+                        <td class="cf_cert_service">
+                            <?php echo help('KG이니시스 통합인증서비스에 암호화를 적용합니다. 만일 글자가 깨지는 문제가 발생하면 사용안함으로 적용해 주세요.') ?>
+                            <select name="cf_cert_use_seed" id="cf_cert_use_seed">
+                                <?php echo option_selected("0", $config['cf_cert_use_seed'], "사용안함"); ?>
+                                <?php echo option_selected("1", $config['cf_cert_use_seed'], "사용함"); ?>
+                            </select>
+                        </td>
+                    </tr>
                     <tr>
                         <th scope="row" class="cf_cert_service"><label for="cf_cert_hp">휴대폰 본인확인</label></th>
                         <td class="cf_cert_service">
diff --git a/adm/config_form_update.php b/adm/config_form_update.php
index dafa85ce5..cfe8e16cb 100644
--- a/adm/config_form_update.php
+++ b/adm/config_form_update.php
@@ -105,6 +105,7 @@ $check_keys = array(
     'cf_cert_ipin' => 'char',
     'cf_cert_hp' => 'char',
     'cf_cert_simple' => 'char',
+    'cf_cert_use_seed' => 'int',
     'cf_admin_email' => 'char',
     'cf_admin_email_name' => 'char',
     'cf_add_script' => 'text',
@@ -284,6 +285,7 @@ $sql = " update {$g5['config_table']}
                 cf_cert_ipin = '{$_POST['cf_cert_ipin']}',
                 cf_cert_hp = '{$_POST['cf_cert_hp']}',
                 cf_cert_simple = '{$_POST['cf_cert_simple']}',
+                cf_cert_use_seed = '".(int)$_POST['cf_cert_use_seed']."',
                 cf_cert_kg_cd = '{$_POST['cf_cert_kg_cd']}',
                 cf_cert_kg_mid = '" . trim($_POST['cf_cert_kg_mid']) . "',
                 cf_cert_kcb_cd = '{$_POST['cf_cert_kcb_cd']}',
diff --git a/extend/default.config.php b/extend/default.config.php
index 0df67714a..f634e939f 100644
--- a/extend/default.config.php
+++ b/extend/default.config.php
@@ -1,6 +1,8 @@
 <?php
 if (!defined('_GNUBOARD_')) exit; // 개별 페이지 접근 불가
 
+define('KGINICIS_USE_CERT_SEED', isset($config['cf_cert_use_seed']) ? (int) $config['cf_cert_use_seed'] : 0);
+
 // 유저 사이드뷰에서 아이콘 지정 안했을시 기본 no 프로필 이미지
 define('G5_NO_PROFILE_IMG', '<span class="profile_img"><img src="'.G5_IMG_URL.'/no_profile.gif" alt="no_profile" width="'.$config['cf_member_icon_width'].'" height="'.$config['cf_member_icon_height'].'"></span>');
 
diff --git a/install/gnuboard5.sql b/install/gnuboard5.sql
index 64c39a8a9..060375457 100644
--- a/install/gnuboard5.sql
+++ b/install/gnuboard5.sql
@@ -292,6 +292,7 @@ CREATE TABLE IF NOT EXISTS `g5_config` (
   `cf_cert_simple` varchar(255) NOT NULL DEFAULT '',
   `cf_cert_kg_cd` varchar(255) NOT NULL DEFAULT '',
   `cf_cert_kg_mid` varchar(255) NOT NULL DEFAULT '',
+  `cf_cert_use_seed` tinyint(4) NOT NULL DEFAULT '0',
   `cf_cert_kcb_cd` varchar(255) NOT NULL DEFAULT '',
   `cf_cert_kcp_cd` varchar(255) NOT NULL DEFAULT '',
   `cf_lg_mid` varchar(100) NOT NULL DEFAULT '',
diff --git a/plugin/inicert/ini_request.php b/plugin/inicert/ini_request.php
index 3eaa70599..d7f4c110d 100644
--- a/plugin/inicert/ini_request.php
+++ b/plugin/inicert/ini_request.php
@@ -17,7 +17,7 @@ if($config['cf_cert_use'] == 2) { // 실서비스 일때
     $mTxId ='SIR_'.$max_cr_id;
 }
 $reqSvcCd ='01';    // 요청구분코드 ["01":간편인증, "02":전자서명]
-$reservedMsg ='isUseToken=Y';   // 결과조회 응답시 개인정보SEED 암호화 처리 요청
+$reservedMsg = (defined('KGINICIS_USE_CERT_SEED') && KGINICIS_USE_CERT_SEED) ? 'isUseToken=Y' : '';   // 결과조회 응답시 개인정보SEED 암호화 처리 요청
 
 // 등록가맹점 확인
 $plainText1 = hash("sha256",(string)$mid.(string)$mTxId.(string)$apiKey);
diff --git a/plugin/inicert/ini_result.php b/plugin/inicert/ini_result.php
index 1fd810281..2299c6b9a 100644
--- a/plugin/inicert/ini_result.php
+++ b/plugin/inicert/ini_result.php
@@ -54,11 +54,13 @@ if ($txId && isset($_POST["resultCode"]) && $_POST["resultCode"] === "0000") {
         $birth_day      = $res_data['userBirthday'];            // 생년월일
         $ci             = $res_data['userCi'];                  // CI
         
-        // 개인정보SEED 암호화 된것을 복호화 합니다.
-        $user_name = decrypt_SEED($user_name, $SEEDKEY, $SEEDIV);
-        $phone_no = decrypt_SEED($phone_no, $SEEDKEY, $SEEDIV);
-        $birth_day = decrypt_SEED($birth_day, $SEEDKEY, $SEEDIV);
-        $ci = decrypt_SEED($ci, $SEEDKEY, $SEEDIV);
+        if (defined('KGINICIS_USE_CERT_SEED') && KGINICIS_USE_CERT_SEED) {
+            // 개인정보SEED 암호화 된것을 복호화 합니다.
+            $user_name = decrypt_SEED($user_name, $SEEDKEY, $SEEDIV);
+            $phone_no = decrypt_SEED($phone_no, $SEEDKEY, $SEEDIV);
+            $birth_day = decrypt_SEED($birth_day, $SEEDKEY, $SEEDIV);
+            $ci = decrypt_SEED($ci, $SEEDKEY, $SEEDIV);
+        }
 
         @insert_cert_history($member['mb_id'], 'inicis', $cert_type); // 인증성공 시 내역 기록
 
diff --git a/plugin/inicert/libs/INILib.php b/plugin/inicert/libs/INILib.php
index a640688bb..335fe456a 100644
--- a/plugin/inicert/libs/INILib.php
+++ b/plugin/inicert/libs/INILib.php
@@ -67,10 +67,11 @@ function decrypt_SEED($str, $bszUser_key, $bszIV) {
     $pdwRoundKey = array_pad(array(), 32, 0);
 
     $bszPlainText = null;
+    $planBytresMessage = array();
 
     // 방법 1
     $bszPlainText = KISA_SEED_CBC::SEED_CBC_Decrypt($keyBytes, $IVBytes, $planBytes, 0, count($planBytes));
-    for ($i = 0; $i < sizeof($bszPlainText); $i++) {
+    for ($i = 0; $i < sizeof((array) $bszPlainText); $i++) {
         $planBytresMessage[] = sprintf("%02X", $bszPlainText[$i]);
     }
     return Hex2String($planBytresMessage);
diff --git a/plugin/inicert/libs/KISA_SEED_CBC.php b/plugin/inicert/libs/KISA_SEED_CBC.php
index 6a3498480..d45374d00 100644
--- a/plugin/inicert/libs/KISA_SEED_CBC.php
+++ b/plugin/inicert/libs/KISA_SEED_CBC.php
@@ -171,7 +171,7 @@ if (!defined('_KISA_SEED_KEY_')) {
 
         var $key_data = null;
 
-        function KISA_SEED_KEY() {
+        function __construct() {
             $this->key_data = array_pad(array(), 32, 0);
         }
 
@@ -192,7 +192,7 @@ if (!defined('_KISA_SEED_INFO_')) {
         var $cbc_last_block = null;
         var $last_block_flag = 0;
 
-        function KISA_SEED_INFO() {
+        function __construct() {
             $this->ivec = array_pad(array(), 4, 0);
             $this->seed_key = new KISA_SEED_KEY();
             $this->cbc_buffer = array_pad(array(), 4, 0);