diff --git a/Gemfile b/Gemfile
index a1b5f31e7731997a6ef5341ba37093a238e805b5..60e07c93b11f6cc5726cdccda797b5a3c99b1f92 100644
--- a/Gemfile
+++ b/Gemfile
@@ -23,9 +23,6 @@ gem "redis", ">= 4.0.1"
 # Use Kredis to get higher-level data types in Redis [https://github.com/rails/kredis]
 # gem "kredis"
 
-# Use Active Model has_secure_password [https://guides.rubyonrails.org/active_model_basics.html#securepassword]
-gem "bcrypt", "~> 3.1.7"
-
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem "tzinfo-data", platforms: %i[ windows jruby ]
 
@@ -70,6 +67,8 @@ gem "icalendar", "~> 2.10"
 
 gem "telegram-bot-ruby", "~> 2.0"
 
+gem 'devise', '~> 4.9'
+
 gem "crono", git: 'https://github.com/plashchynski/crono' #"~> 2.0"
 
 gem "daemons", "~> 1.4"
diff --git a/Gemfile.lock b/Gemfile.lock
index 2a645b20f7f6971d10d251b4522e1955555f47d1..2dc96cd3d35ca23ecc0871325d272bac82de23ee 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -108,6 +108,12 @@ GEM
     debug (1.9.2)
       irb (~> 1.10)
       reline (>= 0.3.8)
+    devise (4.9.4)
+      bcrypt (~> 3.0)
+      orm_adapter (~> 0.1)
+      railties (>= 4.1.0)
+      responders
+      warden (~> 1.2.3)
     drb (2.2.1)
     dry-core (1.0.1)
       concurrent-ruby (~> 1.0)
@@ -201,6 +207,7 @@ GEM
       racc (~> 1.4)
     nokogiri (1.16.5-x86_64-linux)
       racc (~> 1.4)
+    orm_adapter (0.5.0)
     psych (5.1.2)
       stringio
     public_suffix (5.0.5)
@@ -255,6 +262,9 @@ GEM
     regexp_parser (2.9.0)
     reline (0.5.0)
       io-console (~> 0.5)
+    responders (3.1.1)
+      actionpack (>= 5.2)
+      railties (>= 5.2)
     rexml (3.2.8)
       strscan (>= 3.0.9)
     rubyzip (2.3.2)
@@ -303,6 +313,8 @@ GEM
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     uri (0.13.0)
+    warden (1.2.9)
+      rack (>= 2.0.9)
     web-console (4.2.1)
       actionview (>= 6.0.0)
       activemodel (>= 6.0.0)
@@ -330,6 +342,7 @@ DEPENDENCIES
   crono!
   daemons (~> 1.4)
   debug
+  devise (~> 4.9)
   hotwire-rails (~> 0.1.3)
   httparty
   icalendar (~> 2.10)
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 001ed300f4d3e8bc96c0c2972b8fb37989379994..09705d12ab4dfe301535a973e2607fad4efc9d0d 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -1,9 +1,2 @@
 class ApplicationController < ActionController::Base
-  helper_method :current_user
-
-  private
-
-  def current_user
-    @current_user ||= User.find_by(id: session[:user_id]) if session[:user_id]
-  end
 end
diff --git a/app/controllers/candidates_controller.rb b/app/controllers/candidates_controller.rb
index 4b5afa66eda13004faca5fbc7f12e46eb3fdbe5b..09079378d13377fd62ee1a5384b8abb09d6c7ac8 100644
--- a/app/controllers/candidates_controller.rb
+++ b/app/controllers/candidates_controller.rb
@@ -4,8 +4,7 @@ class CandidatesController < ApplicationController
   def create
     @session = Session.find_by(ref_id: params[:session_ref_id])
     @conference = Conference.find_by(slug: params[:conference_slug])
-    @user = User.find(session[:user_id])
-    @candidate = Candidate.find_or_initialize_by(user: @user, session: @session).tap do |candidate_|
+    @candidate = Candidate.find_or_initialize_by(user: current_user, session: @session).tap do |candidate_|
       candidate_.note = params[:note]
       candidate_.save!
     end
@@ -41,8 +40,7 @@ class CandidatesController < ApplicationController
 
   def destroy_self
     @session = Session.find_by(ref_id: params[:session_ref_id])
-    user = User.find(session[:user_id])
-    @candidate = Candidate.find_by(user:, session: @session)
+    @candidate = Candidate.find_by(user: current_user, session: @session)
     destroy_candidate(@session, @candidate)
   end
 
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 8c4133c639be97c24f8afdc3ba5c232e4ed8d438..3e74dea87f6c1d4315d3f8120bb87b404d13a14d 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -1,49 +1,2 @@
 class UsersController < ApplicationController
-  before_action :require_login, except: [:login]
-
-  def login
-    @users = User.all
-    if params[:user_id]
-      user = User.find(params[:user_id])
-      session[:user_id] = user.id
-      redirect_to conferences_path, notice: "Logged in as #{user.name}"
-    end
-  end
-
-  def logout
-    session[:user_id] = nil
-    redirect_to login_path, notice: "Logged out"
-  end
-
-  def profile
-    @user = current_user
-  end
-
-  def update_profile
-    @user = current_user
-    logger.debug(@user)
-    if @user.update(user_params)
-      logger.debug(@user)
-      flash.now[:notice] = "Profile updated successfully!"
-      respond_to do |format|
-        format.html { redirect_to profile_path, notice: "Profile updated successfully!"  }
-        format.turbo_stream { render turbo_stream: turbo_stream.replace("flash", partial: "shared/flash") }
-      end
-    else
-      render :profile
-    end
-  end
-
-  private
-
-  def user_params
-    params.require(:user).permit(:name, :email, :password, :avatar_color, :telegram_username)
-  end
-
-  def require_login
-    unless current_user
-      flash[:alert] = "You must be logged in to edit your profile."
-      redirect_to login_path
-    end
-  end
 end
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index db5791d8dccaf0db38968adb3ffcbb488c91a5f0..6a2eda15af99efbbfddf78c8234fd76ef8f2005d 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1,11 +1,7 @@
 module ApplicationHelper
-  def logged_in?
-    !session[:user_id].nil?
-  end
-
   def body_data_attributes
     attributes = {}
-    attributes[:loggedin_uid] = session[:user_id] if logged_in?
+    attributes[:loggedin_uid] = current_user.id if user_signed_in?
     { data: attributes }
   end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index c6a2a7a9166ba36f79cc3963f677daa6ac477f30..82a1d1f66df17d82f6fe75c076116daeb73a6029 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,9 +1,8 @@
 class User < ApplicationRecord
+  devise :database_authenticatable, :registerable, :rememberable
   has_many :assignments
   has_many :candidates
 
-  has_secure_password
-
   validates :password, presence: true, length: { minimum: 6 }, allow_nil: true
   validates :email, uniqueness: { case_sensitive: false, message: "already in use" }
 
diff --git a/app/views/devise/registrations/edit.html.erb b/app/views/devise/registrations/edit.html.erb
index b82e3365a3a2f8525d013ed424d4092c42901cec..c8cc8217448011cdee295780cf33fff60120fc16 100644
--- a/app/views/devise/registrations/edit.html.erb
+++ b/app/views/devise/registrations/edit.html.erb
@@ -1,11 +1,17 @@
-<h2>Edit <%= resource_name.to_s.humanize %></h2>
+<div>
+<h1 class="font-bold text-4xl">Profile</h1>
 
 <%= form_for(resource, as: resource_name, url: registration_path(resource_name), html: { method: :put }) do |f| %>
   <%= render "devise/shared/error_messages", resource: resource %>
 
+  <div class="field">
+    <%= f.label :name %><br />
+    <%= f.text_field :name, autofocus: true, autocomplete: "username" %>
+  </div>
+
   <div class="field">
     <%= f.label :email %><br />
-    <%= f.email_field :email, autofocus: true, autocomplete: "email" %>
+    <%= f.email_field :email, autocomplete: "email" %>
   </div>
 
   <% if devise_mapping.confirmable? && resource.pending_reconfirmation? %>
@@ -26,18 +32,30 @@
     <%= f.password_field :password_confirmation, autocomplete: "new-password" %>
   </div>
 
+  <div class="field">
+    <%= f.label :avatar_color %>
+    <%= f.color_field :avatar_color %>
+  </div>
+
+
+  <div class="field hidden">
+    <%= f.label :telegram_username %>
+    <%= f.text_field :telegram_username %>
+  </div>
+
   <div class="field">
     <%= f.label :current_password %> <i>(we need your current password to confirm your changes)</i><br />
     <%= f.password_field :current_password, autocomplete: "current-password" %>
   </div>
 
   <div class="actions">
-    <%= f.submit "Update" %>
+    <%= f.submit "Update Profile" %>
   </div>
 <% end %>
 
-<h3>Cancel my account</h3>
+<h2 class="hidden">Cancel my account</h2>
 
-<div>Unhappy? <%= button_to "Cancel my account", registration_path(resource_name), data: { confirm: "Are you sure?", turbo_confirm: "Are you sure?" }, method: :delete %></div>
+<div class="hidden">Unhappy? <%= button_to "Cancel my account", registration_path(resource_name), data: { confirm: "Are you sure?", turbo_confirm: "Are you sure?" }, method: :delete %></div>
 
 <%= link_to "Back", :back %>
+</div>
diff --git a/app/views/devise/registrations/new.html.erb b/app/views/devise/registrations/new.html.erb
index d655b66f6f54f08e4d8d30402226886795067460..e910dc31f8bc54f71c507d815c0bc5a5db05dc2e 100644
--- a/app/views/devise/registrations/new.html.erb
+++ b/app/views/devise/registrations/new.html.erb
@@ -1,11 +1,12 @@
-<h2>Sign up</h2>
+<div>
+<h1 class="font-bold text-4xl">Sign Up</h1>
 
 <%= form_for(resource, as: resource_name, url: registration_path(resource_name)) do |f| %>
   <%= render "devise/shared/error_messages", resource: resource %>
 
   <div class="field">
-    <%= f.label :email %><br />
-    <%= f.email_field :email, autofocus: true, autocomplete: "email" %>
+    <%= f.label :name %><br />
+    <%= f.text_field :name, autofocus: true, autocomplete: "username" %>
   </div>
 
   <div class="field">
@@ -27,3 +28,4 @@
 <% end %>
 
 <%= render "devise/shared/links" %>
+</div>
diff --git a/app/views/devise/sessions/new.html.erb b/app/views/devise/sessions/new.html.erb
index 5ede96489dea7f622fa0302378cdb57518078b1b..60578f76c71bd6f2f2263de7cb0a32f67d50c490 100644
--- a/app/views/devise/sessions/new.html.erb
+++ b/app/views/devise/sessions/new.html.erb
@@ -1,9 +1,10 @@
-<h2>Log in</h2>
+<div>
+<h1 class="font-bold text-4xl">Log in</h1>
 
-<%= form_for(resource, as: resource_name, url: session_path(resource_name)) do |f| %>
+<%= form_for(resource, as: resource_name, url: user_session_path) do |f| %>
   <div class="field">
-    <%= f.label :email %><br />
-    <%= f.email_field :email, autofocus: true, autocomplete: "email" %>
+    <%= f.label :name %><br />
+    <%= f.text_field :name, autofocus: true, autocomplete: "username" %>
   </div>
 
   <div class="field">
@@ -24,3 +25,4 @@
 <% end %>
 
 <%= render "devise/shared/links" %>
+</div>
diff --git a/app/views/devise/shared/_links.html.erb b/app/views/devise/shared/_links.html.erb
index 7a75304badb53b2b15261fddc46e4cb9823c367d..3fad3202510f5f73e35246ccbd68de10688fa679 100644
--- a/app/views/devise/shared/_links.html.erb
+++ b/app/views/devise/shared/_links.html.erb
@@ -1,5 +1,5 @@
 <%- if controller_name != 'sessions' %>
-  <%= link_to "Log in", new_session_path(resource_name) %><br />
+  <%= link_to "Log in", new_user_session_path %><br />
 <% end %>
 
 <%- if devise_mapping.registerable? && controller_name != 'registrations' %>
diff --git a/app/views/layouts/application.html.erb b/app/views/layouts/application.html.erb
index 45f37abdebbeb4d6ddc72321c486e18f5f02bc82..fe495f8d42c6a6f5e08e0f42eb72af0d8e7c55f6 100644
--- a/app/views/layouts/application.html.erb
+++ b/app/views/layouts/application.html.erb
@@ -20,14 +20,15 @@
           <div><%= link_to 'Assignments', assignments_path %></div>
         </div>
         <div class="main-nav-right flex-row">
-          <% if logged_in? %>
+          <% if user_signed_in? %>
             logged in as <%= render partial: 'application/user_avatar', locals: { user: current_user } %>
-            <%= link_to 'My Profile', profile_path %>
+            <%= link_to 'My Profile', edit_user_registration_path %>
             <%= link_to 'My Assignments', user_assignments_path(current_user) %>
-            <%= link_to 'Logout', logout_path, data: { turbo_method: :post } %>
+            <%= link_to 'Logout', destroy_user_session_path, data: { turbo_method: :delete } %>
           <% else %>
             not logged in
-            <%= link_to 'Login', login_path %>
+            <%= link_to 'Login', new_user_session_path %>
+            <%= link_to 'Sign Up', new_user_registration_path %>
           <% end %>
         </div>
       </div>
diff --git a/config/initializers/devise.rb b/config/initializers/devise.rb
new file mode 100644
index 0000000000000000000000000000000000000000..5bb8a009b785b735d4a413180355df86cb763199
--- /dev/null
+++ b/config/initializers/devise.rb
@@ -0,0 +1,313 @@
+# frozen_string_literal: true
+
+# Assuming you have not yet modified this file, each configuration option below
+# is set to its default value. Note that some are commented out while others
+# are not: uncommented lines are intended to protect your configuration from
+# breaking changes in upgrades (i.e., in the event that future versions of
+# Devise change the default values for those options).
+#
+# Use this hook to configure devise mailer, warden hooks and so forth.
+# Many of these configuration options can be set straight in your model.
+Devise.setup do |config|
+  # The secret key used by Devise. Devise uses this key to generate
+  # random tokens. Changing this key will render invalid all existing
+  # confirmation, reset password and unlock tokens in the database.
+  # Devise will use the `secret_key_base` as its `secret_key`
+  # by default. You can change it below and use your own secret key.
+  # config.secret_key = '343ab7c2b98754aaa5d65bd610cf08c3c7b05de6be1d6ce68192595bbfe041d62cd5202a3493221a806183bf31c709c9381b37b6c5372c1ff644391171ae0e4c'
+
+  # ==> Controller configuration
+  # Configure the parent class to the devise controllers.
+  # config.parent_controller = 'DeviseController'
+
+  # ==> Mailer Configuration
+  # Configure the e-mail address which will be shown in Devise::Mailer,
+  # note that it will be overwritten if you use your own mailer class
+  # with default "from" parameter.
+  config.mailer_sender = 'please-change-me-at-config-initializers-devise@example.com'
+
+  # Configure the class responsible to send e-mails.
+  # config.mailer = 'Devise::Mailer'
+
+  # Configure the parent class responsible to send e-mails.
+  # config.parent_mailer = 'ActionMailer::Base'
+
+  # ==> ORM configuration
+  # Load and configure the ORM. Supports :active_record (default) and
+  # :mongoid (bson_ext recommended) by default. Other ORMs may be
+  # available as additional gems.
+  require 'devise/orm/active_record'
+
+  # ==> Configuration for any authentication mechanism
+  # Configure which keys are used when authenticating a user. The default is
+  # just :email. You can configure it to use [:username, :subdomain], so for
+  # authenticating a user, both parameters are required. Remember that those
+  # parameters are used only when authenticating and not when retrieving from
+  # session. If you need permissions, you should implement that in a before filter.
+  # You can also supply a hash where the value is a boolean determining whether
+  # or not authentication should be aborted when the value is not present.
+  config.authentication_keys = [:name]
+
+  # Configure parameters from the request object used for authentication. Each entry
+  # given should be a request method and it will automatically be passed to the
+  # find_for_authentication method and considered in your model lookup. For instance,
+  # if you set :request_keys to [:subdomain], :subdomain will be used on authentication.
+  # The same considerations mentioned for authentication_keys also apply to request_keys.
+  # config.request_keys = []
+
+  # Configure which authentication keys should be case-insensitive.
+  # These keys will be downcased upon creating or modifying a user and when used
+  # to authenticate or find a user. Default is :email.
+  config.case_insensitive_keys = [:name]
+
+  # Configure which authentication keys should have whitespace stripped.
+  # These keys will have whitespace before and after removed upon creating or
+  # modifying a user and when used to authenticate or find a user. Default is :email.
+  config.strip_whitespace_keys = [:name]
+
+  # Tell if authentication through request.params is enabled. True by default.
+  # It can be set to an array that will enable params authentication only for the
+  # given strategies, for example, `config.params_authenticatable = [:database]` will
+  # enable it only for database (email + password) authentication.
+  # config.params_authenticatable = true
+
+  # Tell if authentication through HTTP Auth is enabled. False by default.
+  # It can be set to an array that will enable http authentication only for the
+  # given strategies, for example, `config.http_authenticatable = [:database]` will
+  # enable it only for database authentication.
+  # For API-only applications to support authentication "out-of-the-box", you will likely want to
+  # enable this with :database unless you are using a custom strategy.
+  # The supported strategies are:
+  # :database      = Support basic authentication with authentication key + password
+  # config.http_authenticatable = false
+
+  # If 401 status code should be returned for AJAX requests. True by default.
+  # config.http_authenticatable_on_xhr = true
+
+  # The realm used in Http Basic Authentication. 'Application' by default.
+  # config.http_authentication_realm = 'Application'
+
+  # It will change confirmation, password recovery and other workflows
+  # to behave the same regardless if the e-mail provided was right or wrong.
+  # Does not affect registerable.
+  # config.paranoid = true
+
+  # By default Devise will store the user in session. You can skip storage for
+  # particular strategies by setting this option.
+  # Notice that if you are skipping storage for all authentication paths, you
+  # may want to disable generating routes to Devise's sessions controller by
+  # passing skip: :sessions to `devise_for` in your config/routes.rb
+  config.skip_session_storage = [:http_auth]
+
+  # By default, Devise cleans up the CSRF token on authentication to
+  # avoid CSRF token fixation attacks. This means that, when using AJAX
+  # requests for sign in and sign up, you need to get a new CSRF token
+  # from the server. You can disable this option at your own risk.
+  # config.clean_up_csrf_token_on_authentication = true
+
+  # When false, Devise will not attempt to reload routes on eager load.
+  # This can reduce the time taken to boot the app but if your application
+  # requires the Devise mappings to be loaded during boot time the application
+  # won't boot properly.
+  # config.reload_routes = true
+
+  # ==> Configuration for :database_authenticatable
+  # For bcrypt, this is the cost for hashing the password and defaults to 12. If
+  # using other algorithms, it sets how many times you want the password to be hashed.
+  # The number of stretches used for generating the hashed password are stored
+  # with the hashed password. This allows you to change the stretches without
+  # invalidating existing passwords.
+  #
+  # Limiting the stretches to just one in testing will increase the performance of
+  # your test suite dramatically. However, it is STRONGLY RECOMMENDED to not use
+  # a value less than 10 in other environments. Note that, for bcrypt (the default
+  # algorithm), the cost increases exponentially with the number of stretches (e.g.
+  # a value of 20 is already extremely slow: approx. 60 seconds for 1 calculation).
+  config.stretches = Rails.env.test? ? 1 : 12
+
+  # Set up a pepper to generate the hashed password.
+  # config.pepper = '82470e74f427862d1b8cb8126ee0f9c074d0f8f1a2d4a9d99f0faec7ecdf4f9d2785da6ab609bf6929bec0e43e6469bdc18b5adb65e03d4a31a96879d3c1a414'
+
+  # Send a notification to the original email when the user's email is changed.
+  # config.send_email_changed_notification = false
+
+  # Send a notification email when the user's password is changed.
+  # config.send_password_change_notification = false
+
+  # ==> Configuration for :confirmable
+  # A period that the user is allowed to access the website even without
+  # confirming their account. For instance, if set to 2.days, the user will be
+  # able to access the website for two days without confirming their account,
+  # access will be blocked just in the third day.
+  # You can also set it to nil, which will allow the user to access the website
+  # without confirming their account.
+  # Default is 0.days, meaning the user cannot access the website without
+  # confirming their account.
+  # config.allow_unconfirmed_access_for = 2.days
+
+  # A period that the user is allowed to confirm their account before their
+  # token becomes invalid. For example, if set to 3.days, the user can confirm
+  # their account within 3 days after the mail was sent, but on the fourth day
+  # their account can't be confirmed with the token any more.
+  # Default is nil, meaning there is no restriction on how long a user can take
+  # before confirming their account.
+  # config.confirm_within = 3.days
+
+  # If true, requires any email changes to be confirmed (exactly the same way as
+  # initial account confirmation) to be applied. Requires additional unconfirmed_email
+  # db field (see migrations). Until confirmed, new email is stored in
+  # unconfirmed_email column, and copied to email column on successful confirmation.
+  config.reconfirmable = true
+
+  # Defines which key will be used when confirming an account
+  # config.confirmation_keys = [:email]
+
+  # ==> Configuration for :rememberable
+  # The time the user will be remembered without asking for credentials again.
+  config.remember_for = 2.weeks
+
+  # Invalidates all the remember me tokens when the user signs out.
+  config.expire_all_remember_me_on_sign_out = true
+
+  # If true, extends the user's remember period when remembered via cookie.
+  # config.extend_remember_period = false
+
+  # Options to be passed to the created cookie. For instance, you can set
+  # secure: true in order to force SSL only cookies.
+  # config.rememberable_options = {}
+
+  # ==> Configuration for :validatable
+  # Range for password length.
+  config.password_length = 6..128
+
+  # Email regex used to validate email formats. It simply asserts that
+  # one (and only one) @ exists in the given string. This is mainly
+  # to give user feedback and not to assert the e-mail validity.
+  config.email_regexp = /\A[^@\s]+@[^@\s]+\z/
+
+  # ==> Configuration for :timeoutable
+  # The time you want to timeout the user session without activity. After this
+  # time the user will be asked for credentials again. Default is 30 minutes.
+  # config.timeout_in = 30.minutes
+
+  # ==> Configuration for :lockable
+  # Defines which strategy will be used to lock an account.
+  # :failed_attempts = Locks an account after a number of failed attempts to sign in.
+  # :none            = No lock strategy. You should handle locking by yourself.
+  # config.lock_strategy = :failed_attempts
+
+  # Defines which key will be used when locking and unlocking an account
+  # config.unlock_keys = [:email]
+
+  # Defines which strategy will be used to unlock an account.
+  # :email = Sends an unlock link to the user email
+  # :time  = Re-enables login after a certain amount of time (see :unlock_in below)
+  # :both  = Enables both strategies
+  # :none  = No unlock strategy. You should handle unlocking by yourself.
+  # config.unlock_strategy = :both
+
+  # Number of authentication tries before locking an account if lock_strategy
+  # is failed attempts.
+  # config.maximum_attempts = 20
+
+  # Time interval to unlock the account if :time is enabled as unlock_strategy.
+  # config.unlock_in = 1.hour
+
+  # Warn on the last attempt before the account is locked.
+  # config.last_attempt_warning = true
+
+  # ==> Configuration for :recoverable
+  #
+  # Defines which key will be used when recovering the password for an account
+  # config.reset_password_keys = [:email]
+
+  # Time interval you can reset your password with a reset password key.
+  # Don't put a too small interval or your users won't have the time to
+  # change their passwords.
+  config.reset_password_within = 6.hours
+
+  # When set to false, does not sign a user in automatically after their password is
+  # reset. Defaults to true, so a user is signed in automatically after a reset.
+  # config.sign_in_after_reset_password = true
+
+  # ==> Configuration for :encryptable
+  # Allow you to use another hashing or encryption algorithm besides bcrypt (default).
+  # You can use :sha1, :sha512 or algorithms from others authentication tools as
+  # :clearance_sha1, :authlogic_sha512 (then you should set stretches above to 20
+  # for default behavior) and :restful_authentication_sha1 (then you should set
+  # stretches to 10, and copy REST_AUTH_SITE_KEY to pepper).
+  #
+  # Require the `devise-encryptable` gem when using anything other than bcrypt
+  # config.encryptor = :sha512
+
+  # ==> Scopes configuration
+  # Turn scoped views on. Before rendering "sessions/new", it will first check for
+  # "users/sessions/new". It's turned off by default because it's slower if you
+  # are using only default views.
+  # config.scoped_views = false
+
+  # Configure the default scope given to Warden. By default it's the first
+  # devise role declared in your routes (usually :user).
+  # config.default_scope = :user
+
+  # Set this configuration to false if you want /users/sign_out to sign out
+  # only the current scope. By default, Devise signs out all scopes.
+  # config.sign_out_all_scopes = true
+
+  # ==> Navigation configuration
+  # Lists the formats that should be treated as navigational. Formats like
+  # :html should redirect to the sign in page when the user does not have
+  # access, but formats like :xml or :json, should return 401.
+  #
+  # If you have any extra navigational formats, like :iphone or :mobile, you
+  # should add them to the navigational formats lists.
+  #
+  # The "*/*" below is required to match Internet Explorer requests.
+  # config.navigational_formats = ['*/*', :html, :turbo_stream]
+
+  # The default HTTP method used to sign out a resource. Default is :delete.
+  config.sign_out_via = :delete
+
+  # ==> OmniAuth
+  # Add a new OmniAuth provider. Check the wiki for more information on setting
+  # up on your models and hooks.
+  # config.omniauth :github, 'APP_ID', 'APP_SECRET', scope: 'user,public_repo'
+
+  # ==> Warden configuration
+  # If you want to use other strategies, that are not supported by Devise, or
+  # change the failure app, you can configure them inside the config.warden block.
+  #
+  # config.warden do |manager|
+  #   manager.intercept_401 = false
+  #   manager.default_strategies(scope: :user).unshift :some_external_strategy
+  # end
+
+  # ==> Mountable engine configurations
+  # When using Devise inside an engine, let's call it `MyEngine`, and this engine
+  # is mountable, there are some extra configurations to be taken into account.
+  # The following options are available, assuming the engine is mounted as:
+  #
+  #     mount MyEngine, at: '/my_engine'
+  #
+  # The router that invoked `devise_for`, in the example above, would be:
+  # config.router_name = :my_engine
+  #
+  # When using OmniAuth, Devise cannot automatically set OmniAuth path,
+  # so you need to do it manually. For the users scope, it would be:
+  # config.omniauth_path_prefix = '/my_engine/users/auth'
+
+  # ==> Hotwire/Turbo configuration
+  # When using Devise with Hotwire/Turbo, the http status for error responses
+  # and some redirects must match the following. The default in Devise for existing
+  # apps is `200 OK` and `302 Found` respectively, but new apps are generated with
+  # these new defaults that match Hotwire/Turbo behavior.
+  # Note: These might become the new default in future versions of Devise.
+  config.responder.error_status = :unprocessable_entity
+  config.responder.redirect_status = :see_other
+
+  # ==> Configuration for :registerable
+
+  # When set to false, does not sign a user in automatically after their password is
+  # changed. Defaults to true, so a user is signed in automatically after changing a password.
+  # config.sign_in_after_change_password = true
+end
diff --git a/config/locales/devise.en.yml b/config/locales/devise.en.yml
new file mode 100644
index 0000000000000000000000000000000000000000..260e1c4ba6039a255c7858d049efd734a6200e4b
--- /dev/null
+++ b/config/locales/devise.en.yml
@@ -0,0 +1,65 @@
+# Additional translations at https://github.com/heartcombo/devise/wiki/I18n
+
+en:
+  devise:
+    confirmations:
+      confirmed: "Your email address has been successfully confirmed."
+      send_instructions: "You will receive an email with instructions for how to confirm your email address in a few minutes."
+      send_paranoid_instructions: "If your email address exists in our database, you will receive an email with instructions for how to confirm your email address in a few minutes."
+    failure:
+      already_authenticated: "You are already signed in."
+      inactive: "Your account is not activated yet."
+      invalid: "Invalid %{authentication_keys} or password."
+      locked: "Your account is locked."
+      last_attempt: "You have one more attempt before your account is locked."
+      not_found_in_database: "Invalid %{authentication_keys} or password."
+      timeout: "Your session expired. Please sign in again to continue."
+      unauthenticated: "You need to sign in or sign up before continuing."
+      unconfirmed: "You have to confirm your email address before continuing."
+    mailer:
+      confirmation_instructions:
+        subject: "Confirmation instructions"
+      reset_password_instructions:
+        subject: "Reset password instructions"
+      unlock_instructions:
+        subject: "Unlock instructions"
+      email_changed:
+        subject: "Email Changed"
+      password_change:
+        subject: "Password Changed"
+    omniauth_callbacks:
+      failure: "Could not authenticate you from %{kind} because \"%{reason}\"."
+      success: "Successfully authenticated from %{kind} account."
+    passwords:
+      no_token: "You can't access this page without coming from a password reset email. If you do come from a password reset email, please make sure you used the full URL provided."
+      send_instructions: "You will receive an email with instructions on how to reset your password in a few minutes."
+      send_paranoid_instructions: "If your email address exists in our database, you will receive a password recovery link at your email address in a few minutes."
+      updated: "Your password has been changed successfully. You are now signed in."
+      updated_not_active: "Your password has been changed successfully."
+    registrations:
+      destroyed: "Bye! Your account has been successfully cancelled. We hope to see you again soon."
+      signed_up: "Welcome! You have signed up successfully."
+      signed_up_but_inactive: "You have signed up successfully. However, we could not sign you in because your account is not yet activated."
+      signed_up_but_locked: "You have signed up successfully. However, we could not sign you in because your account is locked."
+      signed_up_but_unconfirmed: "A message with a confirmation link has been sent to your email address. Please follow the link to activate your account."
+      update_needs_confirmation: "You updated your account successfully, but we need to verify your new email address. Please check your email and follow the confirmation link to confirm your new email address."
+      updated: "Your account has been updated successfully."
+      updated_but_not_signed_in: "Your account has been updated successfully, but since your password was changed, you need to sign in again."
+    sessions:
+      signed_in: "Signed in successfully."
+      signed_out: "Signed out successfully."
+      already_signed_out: "Signed out successfully."
+    unlocks:
+      send_instructions: "You will receive an email with instructions for how to unlock your account in a few minutes."
+      send_paranoid_instructions: "If your account exists, you will receive an email with instructions for how to unlock it in a few minutes."
+      unlocked: "Your account has been unlocked successfully. Please sign in to continue."
+  errors:
+    messages:
+      already_confirmed: "was already confirmed, please try signing in"
+      confirmation_period_expired: "needs to be confirmed within %{period}, please request a new one"
+      expired: "has expired, please request a new one"
+      not_found: "not found"
+      not_locked: "was not locked"
+      not_saved:
+        one: "1 error prohibited this %{resource} from being saved:"
+        other: "%{count} errors prohibited this %{resource} from being saved:"
diff --git a/config/routes.rb b/config/routes.rb
index 9f10884a9afee88b726c47286df61229a9a79744..cd2292ffbe757144f65571d54343cee92a56683c 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,17 +1,10 @@
 Rails.application.routes.draw do
+  devise_for :users
   mount Crono::Engine, at: '/crono'
   mount ActionCable.server => '/cable'
 
   get 'speakers/show'
 
-  get 'login', to: 'users#login', as: :login
-  post 'login', to: 'users#login'
-  post 'logout', to: 'users#logout', as: :logout
-  get 'profile', to: 'users#profile', as: :profile
-  patch 'profile', to: 'users#update_profile', as: :update_profile
-  resources :users, only: [:show]
-  # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html
-
   # Reveal health status on /up that returns 200 if the app boots with no exceptions, otherwise 500.
   # Can be used by load balancers and uptime monitors to verify that the app is live.
   get "up" => "rails/health#show", as: :rails_health_check
diff --git a/db/migrate/20241220161958_add_devise_to_users.rb b/db/migrate/20241220161958_add_devise_to_users.rb
new file mode 100644
index 0000000000000000000000000000000000000000..d232e1e0e7397882bf3d107c0d0cec94bbcc194a
--- /dev/null
+++ b/db/migrate/20241220161958_add_devise_to_users.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+class AddDeviseToUsers < ActiveRecord::Migration[7.1]
+  def self.up
+    change_table :users do |t|
+      ## Database authenticatable
+      # t.string :email,              null: false, default: ""
+      t.string :encrypted_password, null: false, default: ""
+
+      ## Recoverable
+      # t.string   :reset_password_token
+      # t.datetime :reset_password_sent_at
+
+      ## Rememberable
+      t.datetime :remember_created_at
+
+      ## Trackable
+      # t.integer  :sign_in_count, default: 0, null: false
+      # t.datetime :current_sign_in_at
+      # t.datetime :last_sign_in_at
+      # t.string   :current_sign_in_ip
+      # t.string   :last_sign_in_ip
+
+      ## Confirmable
+      # t.string   :confirmation_token
+      # t.datetime :confirmed_at
+      # t.datetime :confirmation_sent_at
+      # t.string   :unconfirmed_email # Only if using reconfirmable
+
+      ## Lockable
+      # t.integer  :failed_attempts, default: 0, null: false # Only if lock strategy is :failed_attempts
+      # t.string   :unlock_token # Only if unlock strategy is :email or :both
+      # t.datetime :locked_at
+
+      # Uncomment below if timestamps were not included in your original model.
+      # t.timestamps null: false
+    end
+
+    # add_index :users, :email,                unique: true
+    # add_index :users, :reset_password_token, unique: true
+    # add_index :users, :confirmation_token,   unique: true
+    # add_index :users, :unlock_token,         unique: true
+  end
+
+  def self.down
+    # By default, we don't want to make any assumption about how to roll back a migration when your
+    # model already existed. Please edit below which fields you would like to remove in this migration.
+    raise ActiveRecord::IrreversibleMigration
+  end
+end
diff --git a/db/migrate/20241220203936_remove_password_digest_from_user.rb b/db/migrate/20241220203936_remove_password_digest_from_user.rb
new file mode 100644
index 0000000000000000000000000000000000000000..3c809824513e1dc878d1cedd6014a258940130ee
--- /dev/null
+++ b/db/migrate/20241220203936_remove_password_digest_from_user.rb
@@ -0,0 +1,5 @@
+class RemovePasswordDigestFromUser < ActiveRecord::Migration[7.1]
+  def change
+    remove_column :users, :password_digest
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index bcd53dd3b0425adb96a3c101aa24aed72370f16f..d37ec25374513331a99c1d86d95b59d1acbf3a5a 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_11_18_161733) do
+ActiveRecord::Schema[7.1].define(version: 2024_12_20_161958) do
   create_table "assignments", force: :cascade do |t|
     t.integer "user_id", null: false
     t.integer "session_id", null: false
@@ -270,12 +270,15 @@ ActiveRecord::Schema[7.1].define(version: 2024_11_18_161733) do
 
   create_table "users", force: :cascade do |t|
     t.string "name"
-    t.string "email"
+    t.string "email", default: "", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.string "avatar_color"
     t.string "telegram_username"
     t.string "password_digest"
+    t.string "encrypted_password", default: "", null: false
+    t.datetime "remember_created_at"
+    t.index ["email"], name: "index_users_on_email", unique: true
   end
 
   add_foreign_key "assignments", "sessions"