diff --git a/mobile/shop/nicepay/nicepay_result.php b/mobile/shop/nicepay/nicepay_result.php
index c399e0656..8ce1324da 100644
--- a/mobile/shop/nicepay/nicepay_result.php
+++ b/mobile/shop/nicepay/nicepay_result.php
@@ -117,10 +117,11 @@ if($authResultCode === "0000"){
 	        $ResultCode = nicepay_res('ResultCode', $respArr);
 	        $ResultMsg = nicepay_res('ResultMsg', $respArr);
 	        $tno             = nicepay_res('TID', $respArr);
-	        $amount          = (int) nicepay_res('Amt', $respArr, 0);
-        $app_time        = nicepay_res('AuthDate', $respArr);
-        $pay_method = nicepay_res('PayMethod', $respArr);
-        $od_app_no = $app_no    = nicepay_res('AuthCode', $respArr); // 승인 번호  (신용카드, 계좌이체, 휴대폰)
+	        $response_amt    = nicepay_res('Amt', $respArr, 0);
+	        $amount          = (int) $response_amt;
+	        $app_time        = nicepay_res('AuthDate', $respArr);
+	        $pay_method = nicepay_res('PayMethod', $respArr);
+	        $od_app_no = $app_no    = nicepay_res('AuthCode', $respArr); // 승인 번호  (신용카드, 계좌이체, 휴대폰)
         $pay_type   = $NICEPAY_METHOD[$pay_method];
 
 	        // 승인된 코드가 아니면 결제가 되지 않게 합니다.
@@ -129,6 +130,13 @@ if($authResultCode === "0000"){
 	            die();
 	        }
 
+	        $responseSignature = nicepay_res('Signature', $respArr);
+	        $responseSignData = bin2hex(hash('sha256', $tno . $mid . $response_amt . $merchantKey, true));
+
+	        if ($responseSignature != $responseSignData) {
+	            alert("승인 응답 유효성 검증이 틀려서 결제를 진행할수 없습니다.", G5_SHOP_URL);
+	        }
+
 	        if ($amount != $order_price) {
 	            if($amount > 0) {
 	                $od_id = $moid;
diff --git a/mobile/shop/nicepay/orderform.1.php b/mobile/shop/nicepay/orderform.1.php
index 458ce71a6..5c316728b 100644
--- a/mobile/shop/nicepay/orderform.1.php
+++ b/mobile/shop/nicepay/orderform.1.php
@@ -71,10 +71,11 @@ function nicepay_create_signdata(frm)
     var result = true;
     $.ajax({
         url: g5_url+"/shop/nicepay/createsigndata.php",
-        type: "POST",
-        data: {
-            price : frm.good_mny.value
-        },
+        type: "POST",
+        data: {
+            price : frm.good_mny.value,
+            moid : frm.Moid ? frm.Moid.value : ''
+        },
         dataType: "json",
         async: false,
         cache: false,
@@ -137,4 +138,4 @@ function nicepay_create_signdata(frm)
 <input type="hidden" name="comm_vat_mny"      value="<?php echo $comm_vat_mny; ?>">         <!-- 부가세	    -->
 <input type="hidden" name="comm_free_mny"     value="<?php echo $comm_free_mny; ?>">        <!-- 비과세 금액 -->
 <?php } ?>
-</form>
\ No newline at end of file
+</form>
diff --git a/mobile/shop/nicepay/return_url_result.php b/mobile/shop/nicepay/return_url_result.php
index c20ee5410..575b14e8f 100644
--- a/mobile/shop/nicepay/return_url_result.php
+++ b/mobile/shop/nicepay/return_url_result.php
@@ -3,12 +3,23 @@ include_once('./_common.php');
 include_once(G5_MSHOP_PATH.'/settle_nicepay.inc.php');
 
 $authResultCode = isset($_POST['AuthResultCode']) ? clean_xss_tags($_POST['AuthResultCode']) : '';		// authentication result code 0000:success
-$authResultMsg = isset($_POST['AuthResultMsg']) ? clean_xss_tags($_POST['AuthResultMsg']) : '';		// authentication result message
-$mid = isset($_POST['MID']) ? clean_xss_tags($_POST['MID']) : '';							// merchant id
-$moid = isset($_POST['Moid']) ? addslashes(clean_xss_tags(stripslashes($_POST['Moid']))) : '';							// order number
-
-$sql = " select * from {$g5['g5_shop_order_data_table']} where od_id = '$moid' ";
-$row = sql_fetch($sql);
+$authResultMsg = isset($_POST['AuthResultMsg']) ? clean_xss_tags($_POST['AuthResultMsg']) : '';		// authentication result message
+$mid = isset($_POST['MID']) ? clean_xss_tags($_POST['MID']) : '';							// merchant id
+$moid = isset($_POST['Moid']) ? addslashes(clean_xss_tags(stripslashes($_POST['Moid']))) : '';							// order number
+
+if ($default['de_nicepay_mid'] != $mid) {
+    alert("요청한 상점 mid와 설정된 mid가 틀리므로 결제를 진행할수 없습니다.", G5_SHOP_URL);
+}
+
+$session_order_id = get_session('ss_order_id');
+$session_personalpay_id = get_session('ss_personalpay_id');
+
+if (!$moid || ($session_order_id != $moid && $session_personalpay_id != $moid)) {
+    alert("요청한 주문번호가 틀려서 결제를 진행할수 없습니다.", G5_SHOP_URL);
+}
+
+$sql = " select * from {$g5['g5_shop_order_data_table']} where od_id = '$moid' and dt_pg = 'nicepay' ";
+$row = sql_fetch($sql);
 
 if (empty($row)) {
     die('');
@@ -19,12 +30,12 @@ $data = unserialize(base64_decode($row['dt_data']));
 if(isset($data['pp_id']) && $data['pp_id']) {
     $order_action_url = G5_HTTPS_MSHOP_URL.'/personalpayformupdate.php';
     $page_return_url  = G5_SHOP_URL.'/personalpayform.php?pp_id='.$data['pp_id'];
-} else {
-    $order_action_url = G5_HTTPS_MSHOP_URL.'/orderformupdate.php';
-    $page_return_url  = G5_SHOP_URL.'/orderform.php';
-    if($_SESSION['ss_direct'])
-        $page_return_url .= '?sw_direct=1';
-}
+} else {
+    $order_action_url = G5_HTTPS_MSHOP_URL.'/orderformupdate.php';
+    $page_return_url  = G5_SHOP_URL.'/orderform.php';
+    if(isset($_SESSION['ss_direct']) && $_SESSION['ss_direct'])
+        $page_return_url .= '?sw_direct=1';
+}
 
 $params = array();
 $var_datas = array();
@@ -84,4 +95,4 @@ if ($authResultCode === '0000') {
     // 실패시
 
     alert('오류 : '.$authResultMsg.' 코드 : '.$authResultCode, $page_return_url);
-}
\ No newline at end of file
+}
diff --git a/mobile/shop/orderform.sub.php b/mobile/shop/orderform.sub.php
index aa21e6b43..bb73153dd 100644
--- a/mobile/shop/orderform.sub.php
+++ b/mobile/shop/orderform.sub.php
@@ -1617,9 +1617,6 @@ function pay_approval()
         f.TaxFreeAmt.value = pf.comm_free_mny.value;
         <?php } ?>
 
-        if (! nicepay_create_signdata(f)) {
-            return false;
-        }
         <?php } ?>
 
         // 주문 정보 임시저장
@@ -1646,6 +1643,10 @@ function pay_approval()
         <?php } ?>
 
         <?php if ($default['de_pg_service'] == 'nicepay') { ?>
+        if (! nicepay_create_signdata(f)) {
+            return false;
+        }
+
         nicepayStart(f);
         return false;
         <?php } ?>
diff --git a/mobile/shop/personalpayform.sub.php b/mobile/shop/personalpayform.sub.php
index 092f9a718..87591ecc5 100644
--- a/mobile/shop/personalpayform.sub.php
+++ b/mobile/shop/personalpayform.sub.php
@@ -305,10 +305,6 @@ function pay_approval()
     f.TaxFreeAmt.value = pf.comm_free_mny.value;
     <?php } ?>
 
-    if (! nicepay_create_signdata(f)) {
-        return false;
-    }
-
     <?php } ?>
 
     //var new_win = window.open("about:blank", "tar_opener", "scrollbars=yes,resizable=yes");
@@ -338,6 +334,10 @@ function pay_approval()
     <?php } ?>
     
     <?php if($default['de_pg_service'] == 'nicepay') { ?>
+        if (! nicepay_create_signdata(f)) {
+            return false;
+        }
+
         nicepayStart(f);
 
         return;
diff --git a/shop/nicepay/cancel_process.php b/shop/nicepay/cancel_process.php
index 34cb29b4f..398bc190f 100644
--- a/shop/nicepay/cancel_process.php
+++ b/shop/nicepay/cancel_process.php
@@ -36,17 +36,31 @@ try{
 		'CharSet' => 'utf-8'
 	);
 
-	/*
-	****************************************************************************************
-	* <Cancel Request>	
-	****************************************************************************************
-	*/	
-	$response = nicepay_reqPost($data, "https://pg-api.nicepay.co.kr/webapi/cancel_process.jsp"); //Cancel API call
-
-    $result = json_decode($response, true);
-	
-}catch(Exception $e){
-	$e->getMessage();
-	$ResultCode = "9999";
-	$ResultMsg = "통신실패";
-}
+	/*
+	****************************************************************************************
+	* <Cancel Request>
+	****************************************************************************************
+	*/
+	$response = nicepay_reqPost($data, "https://pg-api.nicepay.co.kr/webapi/cancel_process.jsp"); //Cancel API call
+
+	$result = json_decode($response, true);
+
+	if (isset($result['ResultCode'])) {
+		$responseTid = isset($result['TID']) ? $result['TID'] : $tid;
+		$responseCancelAmt = isset($result['CancelAmt']) ? $result['CancelAmt'] : $cancelAmt;
+		$responseSignature = isset($result['Signature']) ? $result['Signature'] : '';
+		$responseSignData = bin2hex(hash('sha256', $responseTid . $mid . $responseCancelAmt . $merchantKey, true));
+
+		if ($responseSignature != $responseSignData) {
+			$result['ResultCode'] = '9998';
+			$result['ResultMsg'] = '취소 응답 유효성 검증 실패';
+		}
+	}
+
+}catch(Exception $e){
+	$e->getMessage();
+	$result = array(
+		'ResultCode' => '9999',
+		'ResultMsg'  => '통신실패'
+	);
+}
diff --git a/shop/nicepay/createsigndata.php b/shop/nicepay/createsigndata.php
index cf71725b3..648e98728 100644
--- a/shop/nicepay/createsigndata.php
+++ b/shop/nicepay/createsigndata.php
@@ -2,31 +2,62 @@
 include_once('./_common.php');
 include_once(G5_SHOP_PATH.'/settle_nicepay.inc.php');
 
-$orderNumber = get_session('ss_order_id');
-$is_personalpay_order = false;
+$session_order_id = get_session('ss_order_id');
+$personalpay_id = get_session('ss_personalpay_id');
+$orderNumber = (isset($_POST['moid']) && !is_array($_POST['moid'])) ? addslashes(clean_xss_tags(stripslashes($_POST['moid']))) : '';
+$price_checked = false;
 
-if (! $orderNumber) {
-    $orderNumber = get_session('ss_personalpay_id');
-    $is_personalpay_order = true;
+if (!$orderNumber) {
+    $orderNumber = $session_order_id;
+}
+
+if (!$orderNumber) {
+    $orderNumber = $personalpay_id;
+}
+
+if (! ($default['de_pg_service'] == 'nicepay' && $orderNumber)){
+    die(json_encode(array('error'=>'올바른 방법으로 이용해 주십시오.')));
+}
+
+if ($session_order_id != $orderNumber && $personalpay_id != $orderNumber) {
+    die(json_encode(array('error'=>'주문 정보가 올바르지 않습니다.')));
 }
 
-if (! ($default['de_pg_service'] == 'nicepay' && $orderNumber)){
-    die(json_encode(array('error'=>'올바른 방법으로 이용해 주십시오.')));
-}
-
-$price = isset($_POST['price']) ? preg_replace('#[^0-9]#', '', $_POST['price']) : '';
+$price = (isset($_POST['price']) && !is_array($_POST['price'])) ? preg_replace('#[^0-9]#', '', $_POST['price']) : '';
 
 if (strlen($price) < 1) {
     die(json_encode(array('error'=>'가격이 올바르지 않습니다.')));
 }
 
-if ($is_personalpay_order) {
-    $pp_id = preg_replace('/[^0-9]/', '', get_session('ss_personalpay_id'));
+if ($orderNumber) {
+    $sql = " select dt_data from {$g5['g5_shop_order_data_table']} where od_id = '$orderNumber' and dt_pg = 'nicepay' ";
+    $row = sql_fetch($sql);
+
+    if (isset($row['dt_data']) && $row['dt_data']) {
+        $order_data = unserialize(base64_decode($row['dt_data']));
+        $order_price = (isset($order_data['good_mny'])) ? preg_replace('#[^0-9]#', '', $order_data['good_mny']) : '';
+
+        if (strlen($order_price) < 1 || (int)$order_price !== (int)$price) {
+            die(json_encode(array('error'=>'가격이 올바르지 않습니다.')));
+        }
+
+        $price_checked = true;
+    }
+}
+
+if (!$price_checked && $personalpay_id == $orderNumber) {
+    $pp_id = preg_replace('/[^0-9]/', '', $personalpay_id);
     $pp = sql_fetch(" select pp_id, pp_price from {$g5['g5_shop_personalpay_table']} where pp_id = '$pp_id' and pp_use = '1' ");
 
     if (! (isset($pp['pp_id']) && $pp['pp_id']) || (int)$pp['pp_price'] !== (int)$price) {
         die(json_encode(array('error'=>'가격이 올바르지 않습니다.')));
     }
+
+    $price_checked = true;
+}
+
+if (!$price_checked) {
+    die(json_encode(array('error'=>'주문 정보가 올바르지 않습니다.')));
 }
 
 $ediDate = preg_replace('/[^0-9]/', '', G5_TIME_YMDHIS);
diff --git a/shop/nicepay/nicepay_result.php b/shop/nicepay/nicepay_result.php
index 3d9fadae8..1aa484395 100644
--- a/shop/nicepay/nicepay_result.php
+++ b/shop/nicepay/nicepay_result.php
@@ -114,11 +114,12 @@ if($authResultCode === "0000"){
 
         $ResultCode = nicepay_res('ResultCode', $respArr);
         $ResultMsg = nicepay_res('ResultMsg', $respArr);
-        $tno             = nicepay_res('TID', $respArr);
-        $amount          = (int) nicepay_res('Amt', $respArr, 0);
-        $app_time        = nicepay_res('AuthDate', $respArr);
-        $pay_method = nicepay_res('PayMethod', $respArr);
-        $od_app_no = $app_no    = nicepay_res('AuthCode', $respArr); // 승인 번호  (신용카드, 계좌이체, 휴대폰)
+        $tno             = nicepay_res('TID', $respArr);
+        $response_amt    = nicepay_res('Amt', $respArr, 0);
+        $amount          = (int) $response_amt;
+        $app_time        = nicepay_res('AuthDate', $respArr);
+        $pay_method = nicepay_res('PayMethod', $respArr);
+        $od_app_no = $app_no    = nicepay_res('AuthCode', $respArr); // 승인 번호  (신용카드, 계좌이체, 휴대폰)
         $pay_type   = $NICEPAY_METHOD[$pay_method];
         
         // 승인된 코드가 아니면 결제가 되지 않게 합니다.
@@ -127,6 +128,13 @@ if($authResultCode === "0000"){
             die();
         }
 
+        $responseSignature = nicepay_res('Signature', $respArr);
+        $responseSignData = bin2hex(hash('sha256', $tno . $mid . $response_amt . $merchantKey, true));
+
+        if ($responseSignature != $responseSignData) {
+            alert("승인 응답 유효성 검증이 틀려서 결제를 진행할수 없습니다.", G5_SHOP_URL);
+        }
+
         if ($amount != $order_price) {
             if($amount > 0) {
                 $od_id = $moid;
diff --git a/shop/nicepay/orderform.1.php b/shop/nicepay/orderform.1.php
index 6ab60fd93..5dec9282c 100644
--- a/shop/nicepay/orderform.1.php
+++ b/shop/nicepay/orderform.1.php
@@ -73,10 +73,11 @@ function nicepay_create_signdata(frm)
     var result = true;
     $.ajax({
         url: g5_url+"/shop/nicepay/createsigndata.php",
-        type: "POST",
-        data: {
-            price : frm.good_mny.value
-        },
+        type: "POST",
+        data: {
+            price : frm.good_mny.value,
+            moid : frm.Moid ? frm.Moid.value : ''
+        },
         dataType: "json",
         async: false,
         cache: false,
@@ -95,4 +96,4 @@ function nicepay_create_signdata(frm)
 }
 
 </script>
-<?php }
\ No newline at end of file
+<?php }
diff --git a/shop/settle_nicepay_common.php b/shop/settle_nicepay_common.php
index 319ecc919..128875060 100644
--- a/shop/settle_nicepay_common.php
+++ b/shop/settle_nicepay_common.php
@@ -31,56 +31,69 @@ if (in_array($_SERVER['REMOTE_ADDR'], $pg_allow_ips)) {
     $VbankName      = isset($_POST['VbankName']) ? addslashes(clean_xss_tags(stripslashes($_POST['VbankName']))) : '';           //가상계좌 은행명
     $VbankInputName = isset($_POST['VbankInputName']) ? addslashes(clean_xss_tags(stripslashes($_POST['VbankInputName']))) : '';      //입금자 명
     $CancelDate     = isset($_POST['CancelDate']) ? addslashes(clean_xss_tags(stripslashes($_POST['CancelDate']))) : '';          //취소일시
-    
-    //가상계좌채번시 현금영수증 자동발급신청이 되었을경우 전달되며 
+
+    //가상계좌채번시 현금영수증 자동발급신청이 되었을경우 전달되며
     //RcptTID 에 값이 있는경우만 발급처리 됨
     $RcptTID        = isset($_POST['RcptTID']) ? addslashes(clean_xss_tags(stripslashes($_POST['RcptTID']))) : '';             //현금영수증 거래번호
     $RcptType       = isset($_POST['RcptType']) ? addslashes(clean_xss_tags(stripslashes($_POST['RcptType']))) : '';            //현금 영수증 구분(0:미발행, 1:소득공제용, 2:지출증빙용)
     $RcptAuthCode   = isset($_POST['RcptAuthCode']) ? addslashes(clean_xss_tags(stripslashes($_POST['RcptAuthCode']))) : '';        //현금영수증 승인번호
-    
+
     // 입금통보 코드가 4110 성공이면
     if ($ResultCode === '4110') {
         // 입금결과 처리
-        $sql = " select pp_id, od_id from {$g5['g5_shop_personalpay_table']} where pp_id = '$MOID' and pp_app_no = '$VbankNum' ";
+        $sql = " select pp_id, od_id, pp_price from {$g5['g5_shop_personalpay_table']} where pp_id = '$MOID' and pp_app_no = '$VbankNum' ";
         $row = sql_fetch($sql);
 
         $result = false;
+        $is_personalpay_order = (isset($row['pp_id']) && $row['pp_id']);
         $receipt_time = preg_replace("/([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})([0-9]{2})/", "\\1-\\2-\\3 \\4:\\5:\\6", $AuthDate);
 
-	        if($row['pp_id']) {
-	            // 개인결제 UPDATE
-	            $sql = " update {$g5['g5_shop_personalpay_table']}
-	                        set pp_receipt_price    = '$Amt',
-	                            pp_receipt_time     = '$receipt_time'
-	                        where pp_id = '$MOID'
-	                            and pp_app_no = '$VbankNum' ";
-	            $result = sql_query($sql, false);
+        if($is_personalpay_order) {
+            if((int)$row['pp_price'] === $Amt) {
+                // 개인결제 UPDATE
+                $sql = " update {$g5['g5_shop_personalpay_table']}
+                            set pp_receipt_price    = '$Amt',
+                                pp_receipt_time     = '$receipt_time'
+                            where pp_id = '$MOID'
+                                and pp_app_no = '$VbankNum' ";
+                $result = sql_query($sql, false);
 
-	            if($row['od_id']) {
-	                // 주문서 UPDATE
-	                $sql = " update {$g5['g5_shop_order_table']}
-	                            set od_receipt_price = od_receipt_price + '$Amt',
-	                                od_receipt_time = '$receipt_time',
-	                                od_shop_memo = concat(od_shop_memo, \"\\n개인결제 ".$row['pp_id']." 로 결제완료 - ".$receipt_time."\")
-	                            where od_id = '{$row['od_id']}'
-	                            and od_status = '주문'
-	                            and od_cancel_price = '0' ";
-	                $result = sql_query($sql, FALSE);
-	            }
-	        } else {
-	            // 주문서 UPDATE
-	            $sql = " update {$g5['g5_shop_order_table']}
-	                        set od_receipt_price = '$Amt',
-	                            od_receipt_time = '$receipt_time'
-	                        where od_id = '$MOID'
-	                        and od_app_no = '$VbankNum'
-	                        and od_status = '주문'
-	                        and od_cancel_price = '0' ";
-	            $result = sql_query($sql, FALSE);
-	        }
+                if($row['od_id']) {
+                    // 주문서 UPDATE
+                    $sql = " update {$g5['g5_shop_order_table']}
+                                set od_receipt_price = od_receipt_price + '$Amt',
+                                    od_receipt_time = '$receipt_time',
+                                    od_shop_memo = concat(od_shop_memo, \"\\n개인결제 ".$row['pp_id']." 로 결제완료 - ".$receipt_time."\")
+                                where od_id = '{$row['od_id']}'
+                                and od_status = '주문'
+                                and od_cancel_price = '0' ";
+                    $result = sql_query($sql, FALSE);
+                }
+            }
+        } else {
+            $sql = " select od_id, od_misu
+                        from {$g5['g5_shop_order_table']}
+                        where od_id = '$MOID'
+                        and od_app_no = '$VbankNum'
+                        and od_status = '주문'
+                        and od_cancel_price = '0' ";
+            $od_row = sql_fetch($sql);
+
+            if(isset($od_row['od_id']) && $od_row['od_id'] && (int)$od_row['od_misu'] === $Amt) {
+                // 주문서 UPDATE
+                $sql = " update {$g5['g5_shop_order_table']}
+                            set od_receipt_price = '$Amt',
+                                od_receipt_time = '$receipt_time'
+                            where od_id = '$MOID'
+                            and od_app_no = '$VbankNum'
+                            and od_status = '주문'
+                            and od_cancel_price = '0' ";
+                $result = sql_query($sql, FALSE);
+            }
+        }
 
         if($result) {
-            if ($row['od_id'])
+            if (isset($row['od_id']) && $row['od_id'])
                 $od_id = $row['od_id'];
             else
                 $od_id = $MOID;
@@ -95,7 +108,7 @@ if (in_array($_SERVER['REMOTE_ADDR'], $pg_allow_ips)) {
             if($row['cnt'] == 1) {
                 // 미수금 정보 업데이트
                 $info = get_order_info($od_id);
-                
+
                 $add_update_sql = '';
 
                 // 현금영수증 발급시 1 또는 2 이면