diff --git a/docker-compose.yml b/docker-compose.yml
index c0e5858..c8af98d 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -11,6 +11,7 @@ services:
       - ./lumi2/__init__.py:/app/lumi2/__init__.py:ro
       - ./lumi2/exceptions.py:/app/lumi2/exceptions.py:ro
       - ./lumi2/ldap.py:/app/lumi2/ldap.py:ro
+      - ./lumi2/auth.py:/app/lumi2/auth.py:ro
       - ./lumi2/usermodel.py:/app/lumi2/usermodel.py:ro
       - ./lumi2/webapi.py:/app/lumi2/webapi.py:ro
       - ./lumi2/usermanager.py:/app/lumi2/usermanager.py:ro
diff --git a/lumi2/__init__.py b/lumi2/__init__.py
index c2508a6..eef5011 100644
--- a/lumi2/__init__.py
+++ b/lumi2/__init__.py
@@ -16,6 +16,7 @@ def create_app(test_config=None):
     app = Flask(__name__, instance_relative_config=True)
     app.config.from_mapping(
         SECRET_KEY='ChangeMeInProduction',
+        ADMIN_PASSWORD='pbkdf2:sha256:260000$J9yKJOAvWfvaO9Op$f959d88402f67a5143808a00e35d17e636546f1caf5a85c1b6ab1165d1780448',
         SITE_URL='https://www.example.com/',
         SITE_TITLE='LUMI 2',
         SITE_AUTHOR='LUMI 2 Development Team',
@@ -44,6 +45,9 @@ def create_app(test_config=None):
     except OSError:
         pass
 
+    from . import auth
+    app.register_blueprint(auth.bp)
+
     from . import usermanager
     app.register_blueprint(usermanager.bp)
     app.add_url_rule('/', endpoint='index')
diff --git a/lumi2/auth.py b/lumi2/auth.py
new file mode 100644
index 0000000..22a80f5
--- /dev/null
+++ b/lumi2/auth.py
@@ -0,0 +1,68 @@
+import functools
+
+from flask import (
+    Blueprint, current_app, g, flash, redirect, url_for, session,
+    render_template
+)
+from werkzeug.security import check_password_hash
+
+from flask_wtf import FlaskForm
+from wtforms import ValidationError, PasswordField, SubmitField
+from wtforms.validators import InputRequired
+
+
+bp = Blueprint('auth', __name__)
+
+class LoginForm(FlaskForm):
+    @staticmethod
+    def validate_password(form, field) -> None:
+        if not field.data:
+            raise ValidationError("Please enter a password.")
+        if not check_password_hash(current_app.config['ADMIN_PASSWORD'], field.data):
+            raise ValidationError("Invalid password.")
+
+    password = PasswordField(
+        'Password',
+        [InputRequired('Please enter a password.'), validate_password],
+    )
+
+    submit = SubmitField(
+        'Log In',
+    )
+
+@bp.route("/login", methods=("GET", "POST"))
+def login():
+    form = LoginForm()
+    if form.validate_on_submit():
+        session.clear()
+        session['is_authenticated'] = True
+        return redirect(url_for('index'))
+
+    return render_template('auth/login.html', form=form)
+
+
+@bp.before_app_request
+def load_logged_in_user():
+    authentication_status = session.get('is_authenticated')
+    if authentication_status:
+        g.is_authenticated = authentication_status
+    else:
+        g.is_authenticated = False
+
+
+@bp.route('/logout')
+def logout():
+    session.clear()
+    flash("You were logged out.")
+    return redirect(url_for('index'))
+
+
+def login_required(view):
+    @functools.wraps(view)
+    def wrapped_view(**kwargs):
+        if not g.is_authenticated:
+            return redirect(url_for('auth.login'))
+
+        return view(**kwargs)
+
+    return wrapped_view
diff --git a/lumi2/templates/auth/login.html b/lumi2/templates/auth/login.html
new file mode 100644
index 0000000..03b57a7
--- /dev/null
+++ b/lumi2/templates/auth/login.html
@@ -0,0 +1,20 @@
+{% extends 'base.html' %}
+
+{% block content %}
+<div class="row">
+    <div class="col">
+        <h1 class="text-center">Log In</h1>
+    </div>
+</div>
+<form method="post" enctype="multipart/form-data">
+    {{ form.csrf_token }}
+    <div class="container row align-items-center border rounded m-2">
+        {{ form.password.label(class="col-sm-2 col-form-label text-center") }}
+        {{ form.password(class="col-sm form-control m-2" + (" is-invalid" if form.password.errors else "")) }}
+        {{ form.submit(class_="col-sm-2 btn btn-primary m-2") }}
+        {% if form.password.errors %}
+        <div class="text-center invalid-feedback">{{ form.password.errors[0] }}</div>
+        {% endif %}
+    </div>
+</form>
+{% endblock content %}
diff --git a/lumi2/templates/base.html b/lumi2/templates/base.html
index 3c6f8fa..f401c45 100644
--- a/lumi2/templates/base.html
+++ b/lumi2/templates/base.html
@@ -45,11 +45,19 @@
                             <a class="nav-link" href="{{ url_for('usermanager.group_list') }}">Groups</a>
                         </li>
                     </ul>
+                    {% if g.is_authenticated %}
+                    <div class="d-flex"">
+                        <a class="btn btn-outline-primary"
+                            href="{{ url_for('auth.logout') }}"
+                            role="button">Log Out</a>
+                    </div>
+                    {% else %}
                     <div class="d-flex"">
                         <a class="btn btn-primary"
-                            href="#"
+                            href="{{ url_for('auth.login') }}"
                             role="button">Log In</a>
                     </div>
+                    {% endif%}
                 </div>
             </div>
         </nav>
diff --git a/lumi2/templates/usermanager/group_create.html b/lumi2/templates/usermanager/group_create.html
index f3d4cce..cc42d17 100644
--- a/lumi2/templates/usermanager/group_create.html
+++ b/lumi2/templates/usermanager/group_create.html
@@ -11,7 +11,6 @@
     <input type="text" class="col-sm form-control m-2" id="groupNameInput">
     <a class="col-sm-2 btn btn-secondary m-2" href="{{ url_for('usermanager.group_list') }}" role="button">Cancel</a>
     <button class="col-sm-2 btn btn-primary m-2" type="button" id="createGroupButton">Create Group</button>
-    <p class="col-sm-12 text-danger">
 </div>
 <div class="row border rounded m-2">
     <table class="table table-hover align-middle" id="tableMembers">
diff --git a/lumi2/templates/usermanager/index.html b/lumi2/templates/usermanager/index.html
index c873a0f..10914d4 100644
--- a/lumi2/templates/usermanager/index.html
+++ b/lumi2/templates/usermanager/index.html
@@ -10,6 +10,6 @@
     >
 </div>
 <div class="row justify-content-md-center text-center">
-    <p class="fs-3 text-secondary">This site is still under construction.</p>
+    <p class="fs-3 text-secondary"><i class="bi-cone-striped"></i> This site is still under construction.</p>
 </div>
 {% endblock content %}
diff --git a/lumi2/usermanager.py b/lumi2/usermanager.py
index 127d9a8..9203a96 100644
--- a/lumi2/usermanager.py
+++ b/lumi2/usermanager.py
@@ -16,6 +16,7 @@ from wtforms import (
 )
 from wtforms.validators import InputRequired, Email, EqualTo
 
+from lumi2.auth import login_required
 import lumi2.ldap as ldap
 from lumi2.usermodel import User, Group
 from lumi2.exceptions import InvalidStringFormatException, InvalidImageException
@@ -59,6 +60,7 @@ def index():
 
 
 @bp.route("/users/view/<string:username>")
+@login_required
 def user_view(username: str):
     """Detail view for a specific User.
 
@@ -81,6 +83,7 @@ def user_view(username: str):
 
 
 @bp.route("/users/list")
+@login_required
 def user_list():
     """Displays a list of all users."""
 
@@ -198,6 +201,7 @@ class UserCreationForm(UserUpdateForm):
 
 
 @bp.route("/users/create", methods=("GET", "POST"))
+@login_required
 def user_create():
     """Creation view for a new User.
 
@@ -236,6 +240,7 @@ def user_create():
 
 
 @bp.route("/users/update/<string:username>", methods=("GET", "POST"))
+@login_required
 def user_update(username: str):
     """Update view for a specific User.
 
@@ -285,6 +290,7 @@ def user_update(username: str):
 
 
 @bp.route("/users/delete/<string:username>", methods=("GET", "POST"))
+@login_required
 def user_delete(username: str):
     """Deletion view for a specific User.
 
@@ -327,6 +333,7 @@ def user_delete(username: str):
 
 
 @bp.route("/groups/list")
+@login_required
 def group_list():
     """Displays a list of all groups."""
 
@@ -344,6 +351,7 @@ def group_list():
 
 
 @bp.route("/groups/create")
+@login_required
 def group_create():
     """Creation view for a new group.
 
@@ -365,6 +373,7 @@ def group_create():
 
 
 @bp.route("/groups/update/<string:groupname>")
+@login_required
 def group_update(groupname: str):
     """Detail and Update view for a group.
 
@@ -395,6 +404,7 @@ def group_update(groupname: str):
 
 
 @bp.route("/groups/delete/<string:groupname>", methods=("GET", "POST"))
+@login_required
 def group_delete(groupname: str):
     """Deletion view for a specific Group.
 
diff --git a/lumi2/webapi.py b/lumi2/webapi.py
index 8c0e50e..77101f3 100644
--- a/lumi2/webapi.py
+++ b/lumi2/webapi.py
@@ -1,13 +1,18 @@
 from json import JSONEncoder, JSONDecoder, loads, dumps, JSONDecodeError
 
-from flask import Blueprint, request
-from flask_restful import Resource
+from flask import request, g
+from flask_restful import Resource, abort
 
 import lumi2.ldap as ldap
 from lumi2.usermodel import User, Group
 from lumi2.exceptions import InvalidStringFormatException
 
 
+def _assert_is_authenticated():
+        if not g.is_authenticated:
+            abort(401, message="You are not logged in.")
+
+
 class UserEncoder(JSONEncoder):
     def default(self, obj):
         if isinstance(obj, User):
@@ -38,7 +43,9 @@ class UserResource(Resource):
     """The UserResource is used for API access to users."""
 
     def get(self, username):
-        """Returns the specified in JSON format."""
+        """Returns the specified user in JSON format."""
+
+        _assert_is_authenticated()
 
         try:
             conn = ldap.get_connection()
@@ -77,6 +84,8 @@ class GroupResource(Resource):
             A JSON string and HTTP status code.
         """
 
+        _assert_is_authenticated()
+
         try:
             conn = ldap.get_connection()
         except:
@@ -109,6 +118,8 @@ class GroupResource(Resource):
         json : str , status : int
             A JSON string and HTTP status code.
         """
+
+        _assert_is_authenticated()
     
         group_dict = request.get_json()
         if not isinstance(group_dict, dict):
@@ -172,6 +183,8 @@ class GroupResource(Resource):
             A JSON string and HTTP status code.
         """
 
+        _assert_is_authenticated()
+
         try:
             conn = ldap.get_connection()
         except:
@@ -212,6 +225,8 @@ class GroupMemberResource(Resource):
             error message and HTTP error code are returned.
         """
 
+        _assert_is_authenticated()
+
         try:
             conn = ldap.get_connection()
         except:
@@ -262,6 +277,8 @@ class GroupMemberResource(Resource):
             error message and HTTP error code are returned.
         """
 
+        _assert_is_authenticated()
+
         try:
             conn = ldap.get_connection()
         except: