diff --git a/README.md b/README.md
index 8b13789..fba63d1 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,28 @@
+<h1>Tugas Kelompok PJPB - Smart Contracts</h1>
+
+<h2>Anggota kelompok</h2>
+
+<ul>
+  <li>Arina Salma Salsabila (20/459170/PA/19831)</li>
+  <li>Gabriel Possenti Kheisa Drianasta (19/442374/PA/19123)</li>
+  <li>Gregorius Adi Pradana (20/455382/PA/19597)</li>
+  <li>Haikal Abdurrahman (19/445563/PA/19387)</li>
+  <li>Timothy Cleytus Gultom (20/455390/PA/19605)</li>
+</ul>
+
+<h2>Teknologi</h2>
+
+<ul>
+  <li>Back end: PHP 7.2 (vanilla)</li>
+  <li>Database: MySQL</li>
+  <li>Hosting: DigitalOcean</li>
+</ul>
+
+
+<h2>URL frontend: <a href-"https://testapp.pjpb.gabrielkheisa.xyz/login.php">https://testapp.pjpb.gabrielkheisa.xyz/login.php</a><h2>
+
+<h2>Video demonstrasi dan penjelasan: <a href="https://drive.google.com/drive/u/1/folders/1L0w71TZnqa41XFDGfoZ3mM8ILZQeZeXE">https://drive.google.com/drive/u/1/folders/1L0w71TZnqa41XFDGfoZ3mM8ILZQeZeXE</a></h2>
+
+
+
 
diff --git a/config.php b/config.php
new file mode 100644
index 0000000..5348dc8
--- /dev/null
+++ b/config.php
@@ -0,0 +1,16 @@
+<?php
+/* Database credentials. Assuming you are running MySQL
+server with default setting (user 'root' with no password) */
+define('DB_SERVER', '');
+define('DB_USERNAME', '');
+define('DB_PASSWORD', '');
+define('DB_NAME', '');
+ 
+/* Attempt to connect to MySQL database */
+$link = mysqli_connect(DB_SERVER, DB_USERNAME, DB_PASSWORD, DB_NAME);
+ 
+// Check connection
+if($link === false){
+    die("ERROR: Could not connect. " . mysqli_connect_error());
+}
+?>
\ No newline at end of file
diff --git a/login.php b/login.php
new file mode 100644
index 0000000..c711b45
--- /dev/null
+++ b/login.php
@@ -0,0 +1,156 @@
+<?php
+// Initialize the session
+session_start();
+ 
+// Check if the user is already logged in, if yes then redirect him to welcome page
+if(isset($_SESSION["loggedin"]) && $_SESSION["loggedin"] === true){
+    header("location: welcome.php");
+    exit;
+}
+ 
+// Include config file
+require_once "config.php";
+ 
+// Define variables and initialize with empty values
+$username = $password = "";
+$username_err = $password_err = $login_err = "";
+ 
+// Processing form data when form is submitted
+if($_SERVER["REQUEST_METHOD"] == "POST"){
+ 
+    // Check if username is empty
+    if(empty(trim($_POST["username"]))){
+        $username_err = "Please enter username.";
+    } else{
+        $username = trim($_POST["username"]);
+    }
+    
+    // Check if password is empty
+    if(empty(trim($_POST["password"]))){
+        $password_err = "Please enter your password.";
+    } else{
+        $password = trim($_POST["password"]);
+    }
+    
+    // Validate credentials
+    if(empty($username_err) && empty($password_err)){
+        // Prepare a select statement
+        $sql = "SELECT id, username, password, role, hash FROM user_pjpb WHERE username = ?";
+        
+        if($stmt = mysqli_prepare($link, $sql)){
+            // Bind variables to the prepared statement as parameters
+            mysqli_stmt_bind_param($stmt, "s", $param_username);
+            
+            // Set parameters
+            $param_username = $username;
+            
+            // Attempt to execute the prepared statement
+            if(mysqli_stmt_execute($stmt)){
+                // Store result
+                mysqli_stmt_store_result($stmt);
+                
+                // Check if username exists, if yes then verify password
+                if(mysqli_stmt_num_rows($stmt) == 1){                    
+                    // Bind result variables
+                    mysqli_stmt_bind_result($stmt, $id, $username, $hashed_password, $role, $hash);
+                    if(mysqli_stmt_fetch($stmt)){
+                        if(password_verify($password, $hashed_password)){
+                            // Password is correct, so start a new session
+                            session_start();
+                            
+                            // Store data in session variables
+                            $_SESSION["loggedin"] = true;
+                            $_SESSION["id"] = $id;
+                            $_SESSION["username"] = $username; 
+                            $_SESSION["role"] = $role;
+                            $_SESSION["hash"] = $hash;
+                            
+                            // Redirect user to welcome page
+                            header("location: welcome.php");
+                        } else{
+                            // Password is not valid, display a generic error message
+                            $login_err = "Invalid username or password.";
+                        }
+                    }
+                } else{
+                    // Username doesn't exist, display a generic error message
+                    $login_err = "Invalid username or password.";
+                }
+            } else{
+                echo "Oops! Something went wrong. Please try again later.";
+            }
+
+            // Close statement
+            mysqli_stmt_close($stmt);
+        }
+    }
+    
+    // Close connection
+    mysqli_close($link);
+}
+?>
+ 
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Login</title>
+    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
+    <style>
+        body{ font: 14px sans-serif; }
+        .wrapper{ padding: 20px; 
+                max-width:1200px;
+                }
+
+@media only screen and (max-width: 1200px) {
+  body {
+    
+    font-size: 5em;
+  }
+  h2 {
+  font-size: 2em;
+  }
+  .wrapper {
+  }
+  .form-control {
+  
+  font-size: 1em;
+  }
+  .btn {
+  font-size: 0.8em;
+  height: 2em;
+  }
+}
+    </style>
+</head>
+<body>
+    <div class="wrapper">
+        <h2>Login</h2>
+        <p>Please fill in your credentials to login.</p><br>
+
+        <?php 
+        if(!empty($login_err)){
+            echo '<div class="alert alert-danger">' . $login_err . '</div>';
+        }        
+        ?>
+
+        <form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
+            <div class="form-group">
+                <label>Username</label>
+                <input type="text" name="username" class="form-control <?php echo (!empty($username_err)) ? 'is-invalid' : ''; ?>" value="<?php echo $username; ?>">
+                <span class="invalid-feedback"><?php echo $username_err; ?></span>
+            </div>    
+            <div class="form-group">
+                <label>Password</label>
+                <input type="password" name="password" class="form-control <?php echo (!empty($password_err)) ? 'is-invalid' : ''; ?>">
+                <span class="invalid-feedback"><?php echo $password_err; ?></span>
+            </div>
+            <div class="form-group">
+                <input type="submit" class="btn btn-primary" value="Login">
+            </div>
+                <br>
+            <p>Don't have an account? <a href="register.php">Sign up now</a>.</p>
+        </form>
+    </div>
+</body>
+</html>
\ No newline at end of file
diff --git a/logout.php b/logout.php
new file mode 100644
index 0000000..84e222e
--- /dev/null
+++ b/logout.php
@@ -0,0 +1,14 @@
+<?php
+// Initialize the session
+session_start();
+ 
+// Unset all of the session variables
+$_SESSION = array();
+ 
+// Destroy the session.
+session_destroy();
+ 
+// Redirect to login page
+header("location: login.php");
+exit;
+?>
\ No newline at end of file
diff --git a/register.php b/register.php
new file mode 100644
index 0000000..4b23307
--- /dev/null
+++ b/register.php
@@ -0,0 +1,137 @@
+<?php
+// Include config file
+require_once "config.php";
+ 
+// Define variables and initialize with empty values
+$username = $password = $confirm_password = "";
+$username_err = $password_err = $confirm_password_err = "";
+ 
+// Processing form data when form is submitted
+if($_SERVER["REQUEST_METHOD"] == "POST"){
+ 
+    // Validate username
+    if(empty(trim($_POST["username"]))){
+        $username_err = "Please enter a username.";
+    } elseif(!preg_match('/^[a-zA-Z0-9_]+$/', trim($_POST["username"]))){
+        $username_err = "Username can only contain letters, numbers, and underscores.";
+    } else{
+        // Prepare a select statement
+        $sql = "SELECT id FROM user_pjpb WHERE username = ?";
+        
+        if($stmt = mysqli_prepare($link, $sql)){
+            // Bind variables to the prepared statement as parameters
+            mysqli_stmt_bind_param($stmt, "s", $param_username);
+            
+            // Set parameters
+            $param_username = trim($_POST["username"]);
+            
+            // Attempt to execute the prepared statement
+            if(mysqli_stmt_execute($stmt)){
+                /* store result */
+                mysqli_stmt_store_result($stmt);
+                
+                if(mysqli_stmt_num_rows($stmt) == 1){
+                    $username_err = "This username is already taken.";
+                } else{
+                    $username = trim($_POST["username"]);
+                }
+            } else{
+                echo "Oops! Something went wrong. Please try again later.";
+            }
+
+            // Close statement
+            mysqli_stmt_close($stmt);
+        }
+    }
+    
+    // Validate password
+    if(empty(trim($_POST["password"]))){
+        $password_err = "Please enter a password.";     
+    } elseif(strlen(trim($_POST["password"])) < 6){
+        $password_err = "Password must have atleast 6 characters.";
+    } else{
+        $password = trim($_POST["password"]);
+    }
+    
+    // Validate confirm password
+    if(empty(trim($_POST["confirm_password"]))){
+        $confirm_password_err = "Please confirm password.";     
+    } else{
+        $confirm_password = trim($_POST["confirm_password"]);
+        if(empty($password_err) && ($password != $confirm_password)){
+            $confirm_password_err = "Password did not match.";
+        }
+    }
+    
+    // Check input errors before inserting in database
+    if(empty($username_err) && empty($password_err) && empty($confirm_password_err)){
+        
+        // Prepare an insert statement
+        $sql = "INSERT INTO user_pjpb (username, password) VALUES (?, ?)";
+         
+        if($stmt = mysqli_prepare($link, $sql)){
+            // Bind variables to the prepared statement as parameters
+            mysqli_stmt_bind_param($stmt, "ss", $param_username, $param_password);
+            
+            // Set parameters
+            $param_username = $username;
+            $param_password = password_hash($password, PASSWORD_DEFAULT); // Creates a password hash
+            
+            // Attempt to execute the prepared statement
+            if(mysqli_stmt_execute($stmt)){
+                // Redirect to login page
+                header("location: login.php");
+            } else{
+                echo "Oops! Something went wrong. Please try again later.";
+            }
+
+            // Close statement
+            mysqli_stmt_close($stmt);
+        }
+    }
+    
+    // Close connection
+    mysqli_close($link);
+}
+?>
+ 
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Sign Up</title>
+    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
+    <style>
+        body{ font: 14px sans-serif; }
+        .wrapper{ width: 360px; padding: 20px; }
+    </style>
+</head>
+<body>
+    <div class="wrapper">
+        <h2>Sign Up</h2>
+        <p>Please fill this form to create an account.</p>
+        <form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
+            <div class="form-group">
+                <label>Username</label>
+                <input type="text" name="username" class="form-control <?php echo (!empty($username_err)) ? 'is-invalid' : ''; ?>" value="<?php echo $username; ?>">
+                <span class="invalid-feedback"><?php echo $username_err; ?></span>
+            </div>    
+            <div class="form-group">
+                <label>Password</label>
+                <input type="password" name="password" class="form-control <?php echo (!empty($password_err)) ? 'is-invalid' : ''; ?>" value="<?php echo $password; ?>">
+                <span class="invalid-feedback"><?php echo $password_err; ?></span>
+            </div>
+            <div class="form-group">
+                <label>Confirm Password</label>
+                <input type="password" name="confirm_password" class="form-control <?php echo (!empty($confirm_password_err)) ? 'is-invalid' : ''; ?>" value="<?php echo $confirm_password; ?>">
+                <span class="invalid-feedback"><?php echo $confirm_password_err; ?></span>
+            </div>
+            <div class="form-group">
+                <input type="submit" class="btn btn-primary" value="Submit">
+                <input type="reset" class="btn btn-secondary ml-2" value="Reset">
+            </div>
+            <p>Already have an account? <a href="login.php">Login here</a>.</p>
+        </form>
+    </div>    
+</body>
+</html>
\ No newline at end of file
diff --git a/reset-password.php b/reset-password.php
new file mode 100644
index 0000000..5ac762b
--- /dev/null
+++ b/reset-password.php
@@ -0,0 +1,106 @@
+<?php
+// Initialize the session
+session_start();
+ 
+// Check if the user is logged in, otherwise redirect to login page
+if(!isset($_SESSION["loggedin"]) || $_SESSION["loggedin"] !== true){
+    header("location: login.php");
+    exit;
+}
+ 
+// Include config file
+require_once "config.php";
+ 
+// Define variables and initialize with empty values
+$new_password = $confirm_password = "";
+$new_password_err = $confirm_password_err = "";
+ 
+// Processing form data when form is submitted
+if($_SERVER["REQUEST_METHOD"] == "POST"){
+ 
+    // Validate new password
+    if(empty(trim($_POST["new_password"]))){
+        $new_password_err = "Please enter the new password.";     
+    } elseif(strlen(trim($_POST["new_password"])) < 6){
+        $new_password_err = "Password must have atleast 6 characters.";
+    } else{
+        $new_password = trim($_POST["new_password"]);
+    }
+    
+    // Validate confirm password
+    if(empty(trim($_POST["confirm_password"]))){
+        $confirm_password_err = "Please confirm the password.";
+    } else{
+        $confirm_password = trim($_POST["confirm_password"]);
+        if(empty($new_password_err) && ($new_password != $confirm_password)){
+            $confirm_password_err = "Password did not match.";
+        }
+    }
+        
+    // Check input errors before updating the database
+    if(empty($new_password_err) && empty($confirm_password_err)){
+        // Prepare an update statement
+        $sql = "UPDATE users SET password = ? WHERE id = ?";
+        
+        if($stmt = mysqli_prepare($link, $sql)){
+            // Bind variables to the prepared statement as parameters
+            mysqli_stmt_bind_param($stmt, "si", $param_password, $param_id);
+            
+            // Set parameters
+            $param_password = password_hash($new_password, PASSWORD_DEFAULT);
+            $param_id = $_SESSION["id"];
+            
+            // Attempt to execute the prepared statement
+            if(mysqli_stmt_execute($stmt)){
+                // Password updated successfully. Destroy the session, and redirect to login page
+                session_destroy();
+                header("location: login.php");
+                exit();
+            } else{
+                echo "Oops! Something went wrong. Please try again later.";
+            }
+
+            // Close statement
+            mysqli_stmt_close($stmt);
+        }
+    }
+    
+    // Close connection
+    mysqli_close($link);
+}
+?>
+ 
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Reset Password</title>
+    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
+    <style>
+        body{ font: 14px sans-serif; }
+        .wrapper{ width: 360px; padding: 20px; }
+    </style>
+</head>
+<body>
+    <div class="wrapper">
+        <h2>Reset Password</h2>
+        <p>Please fill out this form to reset your password.</p>
+        <form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post"> 
+            <div class="form-group">
+                <label>New Password</label>
+                <input type="password" name="new_password" class="form-control <?php echo (!empty($new_password_err)) ? 'is-invalid' : ''; ?>" value="<?php echo $new_password; ?>">
+                <span class="invalid-feedback"><?php echo $new_password_err; ?></span>
+            </div>
+            <div class="form-group">
+                <label>Confirm Password</label>
+                <input type="password" name="confirm_password" class="form-control <?php echo (!empty($confirm_password_err)) ? 'is-invalid' : ''; ?>">
+                <span class="invalid-feedback"><?php echo $confirm_password_err; ?></span>
+            </div>
+            <div class="form-group">
+                <input type="submit" class="btn btn-primary" value="Submit">
+                <a class="btn btn-link ml-2" href="welcome.php">Cancel</a>
+            </div>
+        </form>
+    </div>    
+</body>
+</html>
\ No newline at end of file
diff --git a/welcome.php b/welcome.php
new file mode 100644
index 0000000..edb1c5c
--- /dev/null
+++ b/welcome.php
@@ -0,0 +1,133 @@
+<?php
+// Initialize the session
+session_start();
+$checkURL = "https://ropsten.etherscan.io/tx/". htmlspecialchars($_SESSION["hash"]);
+ 
+// Check if the user is logged in, if not then redirect him to login page
+if(!isset($_SESSION["loggedin"]) || $_SESSION["loggedin"] !== true){
+    header("location: login.php");
+    exit;
+}
+?>
+ 
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Welcome</title>
+    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
+    <style>
+        body{ font: 14px sans-serif; text-align: center; }
+
+@media only screen and (max-width: 1200px) {
+  body {
+    text-align: left;
+    font-size: 4em;
+  margin-left:5% !important;
+    
+  }
+  h2 {
+  font-size: 1.5em;
+  }
+  h1 {
+  font-size: 1.5em;
+  
+  }
+  .wrapper {
+  max-width:1200px;
+  }
+  .form-control {
+  
+  font-size: 1em;
+  }
+  .btn {
+  font-size: 1.1em;
+  height: 2.2em;
+  text-align: center;
+  }
+  td {
+  font-size: 1.3em;
+  }
+  .tabel {
+   overflow-x: auto !important;
+  }
+  .ov {
+   overflow-x: auto !important;
+  }
+
+}
+
+    </style>
+</head>
+<body>
+    <div class="wrapper">
+    
+    <h1 class="my-5">Hi, <b><?php echo htmlspecialchars($_SESSION["username"]); ?></b>. Welcome to our site.</h1>
+    <h2 class="my-5">Your role is <b><?php echo htmlspecialchars($_SESSION["role"]); ?></b>.</h2>
+    <h2 class="my-5 ov">Your certificate hash is <?php echo "<a href=\"$checkURL\">";?><b><?php echo htmlspecialchars($_SESSION["hash"]); ?></b></a>.</h2>
+    <h2 class="my-5 ov">Download certificate here : <b><?php echo htmlspecialchars($_SESSION["hash"]); ?></b>.</h2>
+    
+    <?php
+    if($_SESSION["role"] == "Admin"){
+    
+    echo "<div class=\"tabel\"><table class=\"\" style='margin-left: auto; margin-right: auto;'>";
+ echo "<tr><th>Username</th><th>Role</th><th>Certificate hash</th></tr>";
+
+class TableRows extends RecursiveIteratorIterator {
+    function __construct($it) {
+        parent::__construct($it, self::LEAVES_ONLY);
+    }
+
+    function current() {
+        return "<td style='width: 150px; border: 1px solid black;'>" . parent::current(). "</td>";
+    }
+
+    function beginChildren() {
+        echo "<tr>";
+    }
+
+    function endChildren() {
+        echo "</tr>" . "\n";
+    }
+}
+
+// Include config file
+require_once "config.php";
+
+$servername = DB_SERVER;
+$dbname = DB_USERNAME;
+$username = DB_PASSWORD;
+$password = DB_NAME;
+
+try {
+    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
+    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+    $stmt = $conn->prepare("SELECT username, role, hash FROM user_pjpb");
+    $stmt->execute();
+
+    // set the resulting array to associative
+    $result = $stmt->setFetchMode(PDO::FETCH_ASSOC);
+
+    foreach(new TableRows(new RecursiveArrayIterator($stmt->fetchAll())) as $k=>$v) {
+        echo $v;
+    }
+}
+catch(PDOException $e) {
+    echo "Error: " . $e->getMessage();
+}
+$conn = null;
+echo "</table></div><br><br>";
+    
+    
+    }
+    
+    
+    ?>
+    
+    <p>
+        <a href="reset-password.php" class="btn btn-warning ml-5">Reset Your Password</a><br><br>
+        <a href="logout.php" class="btn btn-danger ml-5">Sign Out of Your Account</a>
+    </p>
+    </div>
+</body>
+</html>
\ No newline at end of file