diff --git a/lib/philomena/images/query.ex b/lib/philomena/images/query.ex
index 71749b58..0233874b 100644
--- a/lib/philomena/images/query.ex
+++ b/lib/philomena/images/query.ex
@@ -51,7 +51,7 @@ defmodule Philomena.Images.Query do
         must_not
       end
 
-    %{bool: %{should: should, must_not: must_not}}
+    {:ok, %{bool: %{should: should, must_not: must_not}}}
   end
 
   def user_my_transform(_ctx, _value),
diff --git a/lib/philomena/users/password.ex b/lib/philomena/users/password.ex
index af31ed17..7a14739c 100644
--- a/lib/philomena/users/password.ex
+++ b/lib/philomena/users/password.ex
@@ -1,13 +1,13 @@
 defmodule Philomena.Users.Password do
   def hash_pwd_salt(password, opts \\ []) do
-    pepper = Application.get_env(:philomena, :password_pepper)
-
-    Bcrypt.hash_pwd_salt(<<password::binary, pepper::binary>>, opts)
+    Bcrypt.hash_pwd_salt(<<password::binary, password_pepper()::binary>>, opts)
   end
 
   def verify_pass(password, stored_hash) do
-    pepper = Application.get_env(:philomena, :password_pepper)
+    Bcrypt.verify_pass(<<password::binary, password_pepper()::binary>>, stored_hash)
+  end
 
-    Bcrypt.verify_pass(<<password::binary, pepper::binary>>, stored_hash)
+  defp password_pepper do
+    Application.get_env(:philomena, :password_pepper)
   end
 end
diff --git a/lib/philomena/users/user.ex b/lib/philomena/users/user.ex
index 2227d0ec..8b91316d 100644
--- a/lib/philomena/users/user.ex
+++ b/lib/philomena/users/user.ex
@@ -7,7 +7,7 @@ defmodule Philomena.Users.User do
     password_hash_methods: {&Password.hash_pwd_salt/1, &Password.verify_pass/2}
 
   use Pow.Extension.Ecto.Schema,
-    extensions: [PowResetPassword]
+    extensions: [PowResetPassword, PowPersistentSession]
 
   import Ecto.Changeset
 
@@ -17,7 +17,7 @@ defmodule Philomena.Users.User do
     has_many :links, Philomena.Users.Link
     has_many :verified_links, Philomena.Users.Link, where: [aasm_state: "verified"]
     has_many :public_links, Philomena.Users.Link, where: [public: true, aasm_state: "verified"]
-    has_many :galleries, Philomena.Galleries.Gallery
+    has_many :galleries, Philomena.Galleries.Gallery, foreign_key: :creator_id
     has_many :awards, Philomena.Badges.Award
 
     belongs_to :current_filter, Philomena.Filters.Filter
@@ -116,24 +116,97 @@ defmodule Philomena.Users.User do
     |> validate_required([])
   end
 
-  def otp_secret(%{encrypted_otp_secret: x} = user) when x not in [nil, ""] do
-    Philomena.Users.Encryptor.decrypt_model(
-      user.encrypted_otp_secret,
-      user.encrypted_otp_secret_iv,
-      user.encrypted_otp_secret_salt
-    )
-  end
-
-  def otp_secret(_user), do: nil
-
-  def put_otp_secret(user_or_changeset, secret) do
+  def create_totp_secret_changeset(user) do
+    secret = :crypto.strong_rand_bytes(15) |> Base.encode32()
     data = Philomena.Users.Encryptor.encrypt_model(secret)
 
-    user_or_changeset
+    user
     |> change(%{
       encrypted_otp_secret: data.secret,
       encrypted_otp_secret_iv: data.iv,
       encrypted_otp_secret_salt: data.salt
     })
   end
+
+  def consume_totp_token_changeset(user, token) do
+    cond do
+      totp_valid?(user, token) ->
+        user
+        |> change(%{consumed_timestep: token})
+
+      backup_code_valid?(user, token) ->
+        user
+        |> change(%{otp_backup_codes: remove_backup_code(user, token)})
+
+      true ->
+        user
+        |> add_error(:consumed_timestep, "invalid token")
+    end
+  end
+
+  def totp_changeset(user, params, backup_codes) do
+    token = to_string(params["twofactor_token"])
+
+    case user.otp_required_for_login do
+      true ->
+        # User wants to disable TOTP
+        user
+        |> pow_current_password_changeset(params)
+        |> consume_totp_token_changeset(token)
+        |> disable_totp_changeset()
+
+      false ->
+        # User wants to enable TOTP
+        user
+        |> pow_current_password_changeset(params)
+        |> consume_totp_token_changeset(token)
+        |> enable_totp_changeset(backup_codes)
+    end
+  end
+
+  def random_backup_codes do
+    (1..10)
+    |> Enum.map(fn _i ->
+      :crypto.strong_rand_bytes(6) |> Base.encode16(case: :lower)
+    end)
+  end
+
+
+  defp enable_totp_changeset(user, backup_codes) do
+    hashed_codes =
+      backup_codes
+      |> Enum.map(&Password.hash_pwd_salt/1)
+
+    user
+    |> change(%{
+      otp_required_for_login: true,
+      otp_backup_codes: hashed_codes
+    })
+  end
+
+  defp disable_totp_changeset(user) do
+    user
+    |> change(%{
+      otp_required_for_login: false,
+      otp_backup_codes: []
+    })
+  end
+
+  defp totp_valid?(user, token),
+    do: :pot.valid_totp(token, otp_secret(user), window: 60)
+
+  defp backup_code_valid?(user, token),
+    do: Enum.any?(user.otp_backup_codes, &Password.verify_pass(token, &1))
+
+  defp remove_backup_code(user, token),
+    do: user.otp_backup_codes |> Enum.reject(&Password.verify_pass(token, &1))
+
+
+  defp otp_secret(user) do
+    Philomena.Users.Encryptor.decrypt_model(
+      user.encrypted_otp_secret,
+      user.encrypted_otp_secret_iv,
+      user.encrypted_otp_secret_salt
+    )
+  end
 end
diff --git a/lib/philomena_web/controllers/comment_controller.ex b/lib/philomena_web/controllers/comment_controller.ex
index 147ee825..5a7a666e 100644
--- a/lib/philomena_web/controllers/comment_controller.ex
+++ b/lib/philomena_web/controllers/comment_controller.ex
@@ -1,8 +1,7 @@
 defmodule PhilomenaWeb.CommentController do
   use PhilomenaWeb, :controller
 
-  alias Philomena.{Images.Image, Comments.Comment, Textile.Renderer}
-  alias Philomena.Repo
+  alias Philomena.{Comments.Comment, Textile.Renderer}
   import Ecto.Query
 
   def index(conn, _params) do
diff --git a/lib/philomena_web/controllers/image_controller.ex b/lib/philomena_web/controllers/image_controller.ex
index 86f95a01..c63fd859 100644
--- a/lib/philomena_web/controllers/image_controller.ex
+++ b/lib/philomena_web/controllers/image_controller.ex
@@ -1,7 +1,7 @@
 defmodule PhilomenaWeb.ImageController do
   use PhilomenaWeb, :controller
 
-  alias Philomena.{Images.Image, Comments.Comment, Tags.Tag, Textile.Renderer}
+  alias Philomena.{Images.Image, Comments.Comment, Textile.Renderer}
   alias Philomena.Repo
   import Ecto.Query
 
diff --git a/lib/philomena_web/controllers/profile_controller.ex b/lib/philomena_web/controllers/profile_controller.ex
index 180227dc..e663e629 100644
--- a/lib/philomena_web/controllers/profile_controller.ex
+++ b/lib/philomena_web/controllers/profile_controller.ex
@@ -1,8 +1,7 @@
 defmodule PhilomenaWeb.ProfileController do
   use PhilomenaWeb, :controller
 
-  alias Philomena.{Images, Images.Image, Comments.Comment, Posts.Post, Users.User, Users.Link}
-  alias Philomena.Repo
+  alias Philomena.{Images, Images.Image, Users.User}
   import Ecto.Query
 
   plug :load_and_authorize_resource, model: User, only: :show, id_field: "slug", preload: [awards: :badge, public_links: :tag]
diff --git a/lib/philomena_web/controllers/registration/totp_controller.ex b/lib/philomena_web/controllers/registration/totp_controller.ex
new file mode 100644
index 00000000..34d5035a
--- /dev/null
+++ b/lib/philomena_web/controllers/registration/totp_controller.ex
@@ -0,0 +1,43 @@
+defmodule PhilomenaWeb.Registration.TotpController do
+  use PhilomenaWeb, :controller
+
+  alias Philomena.Users.User
+  alias Philomena.Repo
+
+  def edit(conn, _params) do
+    user = conn.assigns.current_user
+
+    case user.encrypted_otp_secret do
+      nil ->
+        user
+        |> User.create_totp_secret_changeset()
+        |> Repo.update()
+
+        # Redirect to have Pow pick up the changes
+        redirect(conn, to: Routes.registration_totp_path(conn, :edit))
+
+      _ ->
+        changeset = Pow.Plug.change_user(conn)
+        render(conn, "edit.html", changeset: changeset)
+    end
+  end
+
+  def update(conn, params) do
+    backup_codes = User.random_backup_codes()
+
+    conn
+    |> Pow.Plug.current_user()
+    |> User.totp_changeset(params, backup_codes)
+    |> Repo.update()
+    |> case do
+      {:error, changeset} ->
+        render(conn, "edit.html", changeset: changeset)
+      
+      {:ok, user} ->
+        conn
+        |> PhilomenaWeb.Plugs.TotpPlug.update_valid_totp_at_for_session(user)
+        |> put_flash(:totp_backup_codes, backup_codes)
+        |> redirect(to: Routes.registration_totp_path(conn, :edit))
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/philomena_web/controllers/session/totp_controller.ex b/lib/philomena_web/controllers/session/totp_controller.ex
new file mode 100644
index 00000000..ce304146
--- /dev/null
+++ b/lib/philomena_web/controllers/session/totp_controller.ex
@@ -0,0 +1,31 @@
+defmodule PhilomenaWeb.Session.TotpController do
+  use PhilomenaWeb, :controller
+
+  alias Philomena.Users.User
+  alias Philomena.Repo
+
+  def new(conn, _params) do
+    changeset = Pow.Plug.change_user(conn)
+
+    render(conn, "new.html", changeset: changeset)
+  end
+
+  def create(conn, params) do
+    conn
+    |> Pow.Plug.current_user()
+    |> User.consume_totp_token_changeset(params)
+    |> Repo.update()
+    |> case do
+      {:error, _changeset} ->
+        conn
+        |> Pow.Plug.clear_authenticated_user()
+        |> put_flash(:error, "Sorry, invalid TOTP token entered. Please sign in again.")
+        |> redirect(to: Routes.pow_session_path(conn, :new))
+
+      {:ok, user} ->
+        conn
+        |> PhilomenaWeb.Plugs.TotpPlug.update_valid_totp_at_for_session(user)
+        |> redirect(to: "/")
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/philomena_web/plugs/totp_plug.ex b/lib/philomena_web/plugs/totp_plug.ex
new file mode 100644
index 00000000..ae3a8fe8
--- /dev/null
+++ b/lib/philomena_web/plugs/totp_plug.ex
@@ -0,0 +1,58 @@
+defmodule PhilomenaWeb.Plugs.TotpPlug do
+  @moduledoc """
+  This plug ensures that a user session has a valid TOTP.
+
+  ## Example
+
+      plug PhilomenaWeb.TotpPlug
+  """
+
+  alias PhilomenaWeb.Router.Helpers, as: Routes
+
+  @doc false
+  @spec init(any()) :: any()
+  def init(opts), do: opts
+
+  @doc false
+  @spec call(Plug.Conn.t(), any()) :: Plug.Conn.t()
+  def call(conn, _opts) do
+    conn
+    |> Pow.Plug.current_user()
+    |> case do
+      nil  -> conn
+      user -> maybe_require_totp_phase(user, conn)
+    end
+  end
+  
+  defp maybe_require_totp_phase(%{otp_required_for_login: nil}, conn), do: conn
+  defp maybe_require_totp_phase(%{otp_required_for_login: false}, conn), do: conn
+  defp maybe_require_totp_phase(_user, conn) do
+    conn.private
+    |> Map.get(:pow_session_metadata, [])
+    |> Keyword.get(:valid_totp_at)
+    |> case do
+      nil ->
+        conn
+        |> Phoenix.Controller.redirect(to: Routes.session_totp_path(conn, :new))
+        |> Plug.Conn.halt()
+
+      _valid_at ->
+        conn
+    end
+  end
+
+  @doc false
+  @spec update_valid_totp_at_for_session(Plug.Conn.t(), map()) :: Plug.Conn.t()
+  def update_valid_totp_at_for_session(conn, user) do
+    metadata =
+      conn.private
+      |> Map.get(:pow_session_metadata, [])
+      |> Keyword.put(:valid_totp_at, DateTime.utc_now())
+
+    config = Pow.Plug.fetch_config(conn)
+    plug   = Pow.Plug.get_plug(config)
+    conn   = Plug.Conn.put_private(conn, :pow_session_metadata, metadata)
+
+    plug.do_create(conn, user, config)
+  end
+end
\ No newline at end of file
diff --git a/lib/philomena_web/router.ex b/lib/philomena_web/router.ex
index e5ff64ac..048a765b 100644
--- a/lib/philomena_web/router.ex
+++ b/lib/philomena_web/router.ex
@@ -1,6 +1,7 @@
 defmodule PhilomenaWeb.Router do
   use PhilomenaWeb, :router
   use Pow.Phoenix.Router
+  use Pow.Extension.Phoenix.Router, otp_app: :philomena
 
   pipeline :browser do
     plug :accepts, ["html"]
@@ -16,14 +17,28 @@ defmodule PhilomenaWeb.Router do
     plug :accepts, ["json"]
   end
 
+  pipeline :ensure_totp do
+    plug PhilomenaWeb.Plugs.TotpPlug
+  end
+
   scope "/" do
-    pipe_through :browser
+    pipe_through [:browser, :ensure_totp]
   
-    #pow_routes()
+    pow_routes()
+    pow_extension_routes()
   end
 
   scope "/", PhilomenaWeb do
-    pipe_through :browser
+    pipe_through [:browser, :ensure_totp]
+
+    # Additional routes for TOTP
+    scope "/registration", Registration, as: :registration do
+      resources "/totp", TotpController, only: [:edit, :update], singleton: true
+    end
+
+    scope "/session", Session, as: :session do
+      resources "/totp", TotpController, only: [:new, :create], singleton: true
+    end
 
     get "/", ActivityController, :index
 
@@ -39,7 +54,7 @@ defmodule PhilomenaWeb.Router do
     resources "/comments", CommentController, only: [:index]
 
     scope "/filters", Filter, as: :filter do
-      resources "/current", CurrentController, only: [:update], singular: true
+      resources "/current", CurrentController, only: [:update], singleton: true
     end
     resources "/filters", FilterController
     resources "/profiles", ProfileController, only: [:show]
diff --git a/lib/pow_multi_factor/phoenix/controller_callbacks.ex b/lib/pow_multi_factor/phoenix/controller_callbacks.ex
deleted file mode 100644
index 1307d17d..00000000
--- a/lib/pow_multi_factor/phoenix/controller_callbacks.ex
+++ /dev/null
@@ -1,69 +0,0 @@
-defmodule PowMultiFactor.Phoenix.ControllerCallbacks do
-  @moduledoc """
-  Controller callback logic for multi-factor authentication.
-
-  ### 2FA code not submitted
-
-  Triggers on `Pow.Phoenix.SessionController.create/2`.
-
-  When a user with 2FA enabled attempts to sign in without submitting their
-  TOTP token, the session will be cleared, and the user redirected back to
-  `Pow.Phoenix.Routes.session_path/1`.
-
-  ### User updates account
-
-  Triggers on `Pow.Phoenix.RegistrationController.update/2`
-
-  When a user changes their account settings, they are required to confirm a
-  current 2FA token.
-
-  See `PowMultiFactor.Ecto.Schema` for more.
-  """
-
-  use Pow.Extension.Phoenix.ControllerCallbacks.Base
-
-  alias Pow.Plug
-  alias PowMultiFactor.Plug, as: PowMultiFactorPlug
-
-  def before_respond(Pow.Phoenix.SessionController, :create, {:ok, conn}, config) do
-    return_path = routes(conn).session_path(conn, :new)
-
-    clear_unauthorized(conn, config, {:ok, conn}, return_path)
-  end
-
-  def before_respond(Pow.Phoenix.RegistrationController, :update, {:ok, user, conn}, config) do
-    return_path = routes(conn).registration_path(conn, :edit)
-
-    halt_unauthorized(conn, config, {:ok, user, conn}, return_path)
-  end
-
-  defp clear_unauthorized(conn, config, success_response, return_path) do
-    case PowMultiFactorPlug.mfa_authorized?(conn, config) do
-      false -> clear_auth(conn) |> go_back(return_path)
-      true  -> success_response
-    end
-  end
-
-  defp halt_unauthorized(conn, config, success_response, return_path) do
-    case PowMultiFactorPlug.mfa_authorized?(conn, config) do
-      false -> go_back(conn, return_path)
-      true  -> success_response
-    end
-  end
-
-  def clear_auth(conn) do
-    {:ok, conn} = Plug.clear_authenticated_user(conn)
-
-    conn
-  end
-
-  defp go_back(conn, return_path) do
-    error = extension_messages(conn).invalid_multi_factor(conn)
-    conn  =
-      conn
-      |> Phoenix.Controller.put_flash(:error, error)
-      |> Phoenix.Controller.redirect(to: return_path)
-
-    {:halt, conn}
-  end
-end
diff --git a/lib/pow_multi_factor/plug.ex b/lib/pow_multi_factor/plug.ex
deleted file mode 100644
index 33526153..00000000
--- a/lib/pow_multi_factor/plug.ex
+++ /dev/null
@@ -1,37 +0,0 @@
-defmodule PowMultiFactor.Plug do
-  @moduledoc """
-  Plug helper methods.
-  """
-
-  alias Plug.Crypto
-  alias Pow.Plug
-  alias Pow.Config
-
-  def mfa_authorized?(conn, config) do
-    user = Plug.current_user(conn)
-
-    if user.otp_required_for_login do
-      secret = user.__struct__.otp_secret(user)
-      totp = Elixir2fa.generate_totp(secret)
-
-      Crypto.secure_compare(totp, conn.params)
-    else
-      true
-    end
-  end
-
-  def assign_mfa(conn, config) do
-    user = Plug.current_user(conn)
-    repo = Config.repo!(config)
-
-    if user.encrypted_otp_secret in [nil, ""] do
-      {:ok, user} = 
-        user.__struct__.put_otp_secret(Elixir2fa.random_secret())
-        |> repo.update()
-
-      user
-    else
-      user
-    end
-  end
-end
diff --git a/lib/search/parser.ex b/lib/search/parser.ex
index e80466a1..5997a429 100644
--- a/lib/search/parser.ex
+++ b/lib/search/parser.ex
@@ -66,8 +66,9 @@ defmodule Search.Parser do
       {:error, msg} ->
         {:error, msg}
 
-      _ ->
-        {:error, "unknown parsing error"}
+      err ->
+        err
+        #{:error, "unknown parsing error"}
     end
   end
 
diff --git a/mix.exs b/mix.exs
index 090c0c67..5ce58eda 100644
--- a/mix.exs
+++ b/mix.exs
@@ -53,7 +53,6 @@ defmodule Philomena.MixProject do
       {:nimble_parsec, "~> 0.5.1"},
       {:canary, "~> 1.1.1"},
       {:scrivener_ecto, "~> 2.0"},
-      {:elixir2fa, "~> 0.1.0"},
       {:pbkdf2, "~> 2.0"}
     ]
   end