diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2dc8f9e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+vars.php
diff --git a/README.md b/README.md
index 7784b5d..52a6b0e 100644
--- a/README.md
+++ b/README.md
@@ -5,4 +5,17 @@
 ## ホスト
 1. これをインストール：
    - PHP (7.3.31を使う)
-2. このレポをクローン、`git clone https://git.xn--rck9c.xn--tckwe/pk11/nextrip.git`
+   - PostgreSQL (11.14を使う)
+2. このリポジトリをクローン、`git clone https://git.xn--rck9c.xn--tckwe/pk11/nextrip.git`
+3. `vars.php.example`を`vars.php`にコピー
+4. `vars.php`を返照
+5. 以下のテーブルを指定のデータベースに作成：
+   ```sql
+   CREATE TABLE favorites (
+       fav_id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+       stop INT,
+       priority INT,
+       description VARCHAR(2048),
+       key VARCHAR(64)
+   );
+   ```
diff --git a/favicon.ico b/favicon.ico
new file mode 100644
index 0000000..b6ca9bf
Binary files /dev/null and b/favicon.ico differ
diff --git a/index.php b/index.php
index 00ef049..3b95fa0 100644
--- a/index.php
+++ b/index.php
@@ -25,7 +25,23 @@
 	 * For more information, please refer to <http://unlicense.org/>
 	 */
 
-	// Return source code
+	/*
+	 * ##### 使用前に読んでね #####
+	 * 
+	 * 「vars.php.example」を「vars.php」にコピーして、「<……>」を取り替えます。
+	 * 次に、vars.phpに指定データベースを作成して、以下のテーブルを作成します。
+	 * 
+	 * CREATE TABLE favorites (
+	 *     fav_id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+	 *     stop INT,
+	 *     priority INT,
+	 *     description VARCHAR(2048),
+	 *     key VARCHAR(64)
+	 * );
+	 */
+	require_once('vars.php');
+
+	// ソースコードを送信
 	if(isset($_GET['source'])) {
 		header("Content-Type: text/plain");
 		die(file_get_contents(basename($_SERVER['PHP_SELF'])));
@@ -39,10 +55,11 @@
 
 	<title>停留所のNexTrip情報</title>
 
-	<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
+	<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-gH2yIJqKdNHPEq0n4Mqa/HGKIhSkIHeL5AyhkYV8i59U5AR6csBvApHHNl/vI1Bx" crossorigin="anonymous">
 	<style>
 		main {
 			max-width: 768px;
+			margin-bottom: 5rem;
 		}
 
 		h2 {
@@ -56,16 +73,37 @@
 		$stop = $_GET['stop'];
 		$favSet = $_POST['fav-set'];
 		$favRemove = $_POST['fav-remove'];
+		$favUp = $_POST['fav-up'];
+		$favDown = $_POST['fav-down'];
+		$keyMenu = isset($_GET['key-menu']);
+		$keySet = $_POST['key-set'];
+
+		// cookieの変数
+		if(isset($_COOKIE['key'])) {
+			$key = hash('sha256', $_COOKIE['key']);
+			$shortKey = substr($key, 0, 7);
+		}
+
+		// キーを更新
+		if(isset($keySet)) {
+			if(!empty($keySet)) {
+				setcookie("key", $keySet, 2147483647);
+				$key = hash('sha256', $keySet);
+				$shortKey = substr($key, 0, 7);
+			} else {
+				setcookie("key", "", 1);
+				unset($key);
+			}
+		}
 	?>
 
 	<header>
-		<nav class="navbar navbar-light bg-light">
+		<nav class="navbar navbar-expand-sm navbar-light bg-light">
 			<div class="container-fluid">
 				<a class="navbar-brand" href="<?php echo $_SERVER['PHP_SELF']; ?>">停留所のNexTrip情報</a>
 				<ul class="navbar-nav">
-					<li class="nav-item">
-						<a class="nav-link" href="?source">ソース</a>
-					</li>
+					<li class="nav-item"><a class="nav-link" href="?key-menu"><?php echo empty($key) ? 'キー' : ($shortKey . 'さん'); ?></a></li>
+					<li class="nav-item"><a class="nav-link" href="?source">ソース</a></li>
 				</ul>
 			</div>
 		</nav>
@@ -75,6 +113,10 @@
 		<?php
 			date_default_timezone_set('America/Chicago');
 
+			// DBに接続
+			$dbc = pg_connect("host=$DB_HOST dbname=$DB_NAME user=$DB_USER password=$DB_PASSWORD")
+				or die('Could not connect: ' . pg_last_error());
+
 			if(isset($stop)) { // 停留所情報を表示
 				$directions = [
 					"NB" => "北行",
@@ -106,20 +148,33 @@
 					}
 					echo '</div>';
 
-					// お気に入りフォームをプリント
-					$favDesc = json_decode($_COOKIE['favorites'], true)[$stop];
-
-					echo '<form method="post" action="' . $_SERVER['PHP_SELF'] . '">';
-					echo "<input type=\"hidden\" name=\"fav-set\" value=\"$stop\">";
-					echo '<div class="input-group">';
-					echo '<label for="desc" class="input-group-text">お気に入り</label>';
-					echo "<input type=\"text\" id=\"desc\" name=\"desc\" class=\"form-control\" placeholder=\"説明\" value=\"$favDesc\" required>";
-					echo '<input type="submit" class="btn btn-outline-secondary" value="' . (isset($favDesc) ? '更新' : '追加') . '">';
-					echo '</div>';
-					echo '</form>';
+					if(!empty($key)) {
+						// お気に入りフォームをプリント
+						$query = 'SELECT description FROM favorites WHERE favorites.key=$1 AND favorites.stop=$2 LIMIT 1';
+						$res = pg_query_params($query, [$key, $stop]) or die('Query failed: ' . pg_last_error());
+						$row = pg_fetch_array($res);
+	
+						echo '<form method="post" action="' . $_SERVER['PHP_SELF'] . '">';
+						echo '<input type="hidden" name="fav-set" value="' . $stop . '">';
+						echo '<div class="input-group">';
+						echo '<label for="desc" class="input-group-text">お気に入り</label>';
+						echo '<input type="text" id="desc" name="desc" class="form-control" placeholder="説明" value="' . $row['description'] . '" required>';
+						echo '<input type="submit" class="btn btn-outline-secondary" value="' . ($row ? '更新' : '追加') . '">';
+						echo '</div>';
+						echo '</form>';
+					}
 				} else {
 					echo "<div class=\"alert alert-danger\">{$stop}は無効な停留所です。</div>";
 				}
+			} else if($keyMenu) { //キーを設定
+				echo '<form method="post" action="' . $_SERVER['PHP_SELF'] . '">';
+				echo '<div class="input-group mb-3">';
+				echo '<label for="key-set" class="input-group-text">キー</label>';
+				echo '<input type="password" id="key-set" name="key-set" class="form-control" value="' . $_COOKIE['key'] . '">';
+				echo '<input type="submit" class="btn btn-outline-secondary" value="設定">';
+				echo '</div>';
+				echo '</form>';
+				echo '<p>キーを設定して、お気に入りを使用できます。キーを持つ誰でもはあなたのお気に入りを見ることができますので、秘密にしておきましょう。</p>';
 			} else { //　HPを表示
 				// 停留所フォームをプリント
 				echo '<form method="get" action="' . $_SERVER['PHP_SELF'] . '">';
@@ -130,42 +185,105 @@
 				echo '</div>';
 				echo '</form>';
 
-				// お気に入り一覧
-				$favorites = isset($_COOKIE['favorites']) ? json_decode($_COOKIE['favorites'], true) : Array();
-
-				if(isset($favSet)) { // お気に入りに追加
-					$desc = $_POST['desc'];
-
-					$favorites[$favSet] = $desc;
-					ksort($favorites);
-					setcookie("favorites", json_encode($favorites), 2147483647);
-					echo "<div class=\"alert alert-info\">{$favSet}({$desc})は設定しました。</div>";
-				} else if(isset($favRemove)) { // お気に入りから削除
-					if(array_key_exists($favRemove, $favorites)) {
-						$desc = $favorites[$favRemove];
-						unset($favorites[$favRemove]);
-						setcookie("favorites", json_encode($favorites), 2147483647);
-						echo "<div class=\"alert alert-info\">{$favRemove}({$desc})は削除しました。</div>";
-					} else {
-						echo "<div class=\"alert alert-warning\">{$favRemove}はお気に入りにありません。</div>";
+				if(!empty($key)) {
+
+					if(isset($favSet)) { // お気に入りに追加
+						$query = 'SELECT fav_id, stop, description FROM favorites WHERE favorites.key=$1 AND favorites.stop=$2 LIMIT 1';
+						$res = pg_query_params($query, [$key, $favSet]) or die('Query failed: ' . pg_last_error());
+						$row = pg_fetch_array($res);
+	
+						$desc = $_POST['desc'];
+						if(!$row) {
+							$query = 'INSERT INTO favorites (stop, priority, description, key) VALUES ($1, 0, $2, $3)';
+							pg_query_params($query, [$favSet, $desc, $key]);
+							echo "<div class=\"alert alert-success\">$favSet – {$desc}は設定しました。</div>";
+						} else if($desc != $row['description']) {
+							$query = 'UPDATE favorites SET description=$1 WHERE favorites.key=$2 AND favorites.fav_id=$3';
+							pg_query_params($query, [$desc, $key, $row['fav_id']]);
+							echo "<div class=\"alert alert-success\">$favSet – {$desc}は更新しました。</div>";
+						} else {
+							echo "<div class=\"alert alert-info\">{$favSet}はすでに設定しました。</div>";
+						}
+					} else if(isset($favRemove)) { // お気に入りから削除
+						$query = 'SELECT stop, description FROM favorites WHERE favorites.key=$1 AND favorites.fav_id=$2';
+						$res = pg_query_params($query, [$key, $favRemove]) or die('Query failed: ' . pg_last_error());
+						$row = pg_fetch_array($res);
+						if($row) {
+							$stop = $row['stop'];
+							$desc = $row['description'];
+							$query = 'DELETE FROM favorites WHERE favorites.fav_id=$1';
+							pg_query_params($query, [$favRemove]);
+							echo "<div class=\"alert alert-danger\">$stop – {$desc}は削除しました。</div>";
+						} else {
+							echo "<div class=\"alert alert-warning\">亭はお気に入りにありません。</div>";
+						}
+					} else if(isset($favUp)) { // お気に入りを上げる
+						$query = 'SELECT stop, description, priority FROM favorites WHERE favorites.key=$1 AND favorites.fav_id=$2';
+						$res = pg_query_params($query, [$key, $favUp]) or die('Query failed: ' . pg_last_error());
+						$row = pg_fetch_array($res);
+						if($row) {
+							$stop = $row['stop'];
+							$desc = $row['description'];
+							$priority = $row['priority'] + 1;
+							$query = 'UPDATE favorites SET priority=priority+1 WHERE favorites.fav_id=$1';
+							pg_query_params($query, [$favUp]) or die('Query failed: ' . pg_last_error());
+							echo "<div class=\"alert alert-success\">$stop – {$desc}は{$priority}に上げました。</div>";
+						} else {
+							echo "<div class=\"alert alert-warning\">亭はお気に入りにありません。</div>";
+						}
+					} else if(isset($favDown)) { // お気に入りを下げる
+						$query = 'SELECT stop, description, priority FROM favorites WHERE favorites.key=$1 AND favorites.fav_id=$2';
+						$res = pg_query_params($query, [$key, $favDown]) or die('Query failed: ' . pg_last_error());
+						$row = pg_fetch_array($res);
+						if($row) {
+							$stop = $row['stop'];
+							$desc = $row['description'];
+							$priority = $row['priority'] - 1;
+							$query = 'UPDATE favorites SET priority=priority-1 WHERE favorites.fav_id=$1';
+							pg_query_params($query, [$favDown]) or die('Query failed: ' . pg_last_error());
+							echo "<div class=\"alert alert-success\">$stop – {$desc}は{$priority}に下げました。</div>";
+						} else {
+							echo "<div class=\"alert alert-warning\">亭はお気に入りにありません。</div>";
+						}
+					} else if(isset($keySet)) {
+						if(!empty($keySet)) {
+							echo "<div class=\"alert alert-info\">ようこそ、{$shortKey}さん。</div>";
+						} else {
+							echo "<div class=\"alert alert-info\">さようなら、{$shortKey}さん。</div>";
+						}
 					}
-				}
 
-				// お気に入りがある場合、プリント
-				if(count($favorites) > 0) {
-					echo '<h2>お気に入り</h2>';
-					echo '<form action="' . $_SERVER['PHP_SELF'] . '">';
-					echo '<ul class="list-unstyled">';
-					foreach($favorites as $favStop => $favDesc) {
-						echo '<li class="mb-1 d-flex">';
-						echo "<button type=\"submit\" formmethod=\"get\" name=\"stop\" value=\"$favStop\" class=\"btn btn-sm btn-secondary flex-fill me-1 text-start\">$favStop ($favDesc)</button>";
-						echo "<button type=\"submit\" formmethod=\"post\" name=\"fav-remove\" value=\"$favStop\" aria-label=\"{$favStop}を削除\" class=\"btn btn-sm btn-danger\">×</button>";
-						echo '</li>';
+					// お気に入り一覧
+					$query = 'SELECT fav_id, stop, description, priority FROM favorites WHERE favorites.key=$1 ORDER BY favorites.priority DESC, favorites.stop ASC';
+					$res = pg_query_params($query, [$key]) or die('Query failed: ' . pg_last_error());
+	
+					// お気に入りがある場合、プリント
+					if(pg_num_rows($res) > 0) {
+						echo '<h2>お気に入り</h2>';
+						echo '<form action="' . $_SERVER['PHP_SELF'] . '">';
+						echo '<ul class="list-unstyled">';
+						$priority = -1;
+						while($row = pg_fetch_array($res)) {
+							if($priority != $row['priority'] && $priority != -1)
+								echo '<hr>';
+							$priority = $row['priority'];
+	
+							echo '<li class="mb-1 d-flex">';
+							echo '<button type="submit" formmethod="get" name="stop" value="' . $row['stop'] . '" class="btn btn-sm btn-secondary flex-fill me-1 text-start">' . $row['stop'] . ' – ' . $row['description'] . '</button>';
+							echo '<button type="submit" formmethod="post" name="fav-up" value="' . $row['fav_id'] . '" title="' . $row['stop'] . 'の優先を上げる" aria-label="' . $row['stop'] . 'の優先を上げる" class="btn btn-sm btn-outline-secondary me-1">↑</button>';
+							echo '<button type="submit" formmethod="post" name="fav-down" value="' . $row['fav_id'] . '" title="' . $row['stop'] . 'の優先を下げる" aria-label="' . $row['stop'] . 'の優先を下げる" class="btn btn-sm btn-outline-secondary me-1">↓</button>';
+							echo '<button type="submit" formmethod="post" name="fav-remove" value="' . $row['fav_id'] . '" title="' . $row['stop'] . 'を削除" aria-label="' . $row['stop'] . 'を削除" class="btn btn-sm btn-danger">×</button>';
+							echo '</li>';
+						}
+						echo '</ul>';
+						echo '</form>';
 					}
-					echo '</ul>';
-					echo '</form>';
+				} else {
+					echo '<div class="alert alert-info"><a href="?key-menu">キーを設定する</a>と、お気に入りの停留所を保存できます。</div>';
 				}
 			}
+
+			pg_close($dbc);
 		?>
 	</main>
 </body>
diff --git a/vars.php.example b/vars.php.example
new file mode 100644
index 0000000..24f4311
--- /dev/null
+++ b/vars.php.example
@@ -0,0 +1,10 @@
+<?php
+	// アプリコンスタント
+	define('KEY_SALT', '<キーをサルトの文字列>');
+
+	// DBコンスタント
+	$DB_HOST = 'localhost';
+	$DB_NAME = '<DBの名前>';
+	$DB_USER = '<DBロールの名前>';
+	$DB_PASSWORD = '<DBロールのパスワード>';
+?>