Add E2EE API (#13820)

72 files changed, 1453 insertions, 223 deletions

diff --git a/Gemfile b/Gemfile
index 5dc070f4d..00033545f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -50,6 +50,7 @@ gem 'omniauth', '~> 1.9'
 
 gem 'discard', '~> 1.2'
 gem 'doorkeeper', '~> 5.4'
+gem 'ed25519', '~> 1.2'
 gem 'fast_blank', '~> 1.0'
 gem 'fastimage'
 gem 'goldfinger', '~> 2.1'
diff --git a/Gemfile.lock b/Gemfile.lock
index 9348c6516..fe44c85ff 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -201,6 +201,7 @@ GEM
       dotenv (= 2.7.5)
       railties (>= 3.2, < 6.1)
     e2mmap (0.1.0)
+    ed25519 (1.2.4)
     elasticsearch (7.7.0)
       elasticsearch-api (= 7.7.0)
       elasticsearch-transport (= 7.7.0)
@@ -701,6 +702,7 @@ DEPENDENCIES
   doorkeeper (~> 5.4)
   dotenv-rails (~> 2.7)
   e2mmap (~> 0.1.0)
+  ed25519 (~> 1.2)
   fabrication (~> 2.21)
   faker (~> 2.12)
   fast_blank (~> 1.0)
diff --git a/app/controllers/activitypub/claims_controller.rb b/app/controllers/activitypub/claims_controller.rb
new file mode 100644
index 000000000..08ad952df
--- /dev/null
+++ b/app/controllers/activitypub/claims_controller.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class ActivityPub::ClaimsController < ActivityPub::BaseController
+  include SignatureVerification
+  include AccountOwnedConcern
+
+  skip_before_action :authenticate_user!
+
+  before_action :require_signature!
+  before_action :set_claim_result
+
+  def create
+    render json: @claim_result, serializer: ActivityPub::OneTimeKeySerializer
+  end
+
+  private
+
+  def set_claim_result
+    @claim_result = ::Keys::ClaimService.new.call(@account.id, params[:id])
+  end
+end
diff --git a/app/controllers/activitypub/collections_controller.rb b/app/controllers/activitypub/collections_controller.rb
index c1e7aa550..380de54f5 100644
--- a/app/controllers/activitypub/collections_controller.rb
+++ b/app/controllers/activitypub/collections_controller.rb
@@ -5,8 +5,9 @@ class ActivityPub::CollectionsController < ActivityPub::BaseController
   include AccountOwnedConcern
 
   before_action :require_signature!, if: :authorized_fetch_mode?
+  before_action :set_items
   before_action :set_size
-  before_action :set_statuses
+  before_action :set_type
   before_action :set_cache_headers
 
   def show
@@ -16,40 +17,53 @@ class ActivityPub::CollectionsController < ActivityPub::BaseController
 
   private
 
-  def set_statuses
-    @statuses = scope_for_collection
-    @statuses = cache_collection(@statuses, Status)
+  def set_items
+    case params[:id]
+    when 'featured'
+      @items = begin
+        # Because in public fetch mode we cache the response, there would be no
+        # benefit from performing the check below, since a blocked account or domain
+        # would likely be served the cache from the reverse proxy anyway
+
+        if authorized_fetch_mode? && !signed_request_account.nil? && (@account.blocking?(signed_request_account) || (!signed_request_account.domain.nil? && @account.domain_blocking?(signed_request_account.domain)))
+          []
+        else
+          cache_collection(@account.pinned_statuses, Status)
+        end
+      end
+    when 'devices'
+      @items = @account.devices
+    else
+      not_found
+    end
   end
 
   def set_size
     case params[:id]
-    when 'featured'
-      @size = @account.pinned_statuses.count
+    when 'featured', 'devices'
+      @size = @items.size
     else
       not_found
     end
   end
 
-  def scope_for_collection
+  def set_type
     case params[:id]
     when 'featured'
-      # Because in public fetch mode we cache the response, there would be no
-      # benefit from performing the check below, since a blocked account or domain
-      # would likely be served the cache from the reverse proxy anyway
-      if authorized_fetch_mode? && !signed_request_account.nil? && (@account.blocking?(signed_request_account) || (!signed_request_account.domain.nil? && @account.domain_blocking?(signed_request_account.domain)))
-        Status.none
-      else
-        @account.pinned_statuses
-      end
+      @type = :ordered
+    when 'devices'
+      @type = :unordered
+    else
+      not_found
     end
   end
 
   def collection_presenter
     ActivityPub::CollectionPresenter.new(
       id: account_collection_url(@account, params[:id]),
-      type: :ordered,
+      type: @type,
       size: @size,
-      items: @statuses
+      items: @items
     )
   end
 end
diff --git a/app/controllers/api/v1/crypto/deliveries_controller.rb b/app/controllers/api/v1/crypto/deliveries_controller.rb
new file mode 100644
index 000000000..aa9df6e03
--- /dev/null
+++ b/app/controllers/api/v1/crypto/deliveries_controller.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+class Api::V1::Crypto::DeliveriesController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_current_device
+
+  def create
+    devices.each do |device_params|
+      DeliverToDeviceService.new.call(current_account, @current_device, device_params)
+    end
+
+    render_empty
+  end
+
+  private
+
+  def set_current_device
+    @current_device = Device.find_by!(access_token: doorkeeper_token)
+  end
+
+  def resource_params
+    params.require(:device)
+    params.permit(device: [:account_id, :device_id, :type, :body, :hmac])
+  end
+
+  def devices
+    Array(resource_params[:device])
+  end
+end
diff --git a/app/controllers/api/v1/crypto/encrypted_messages_controller.rb b/app/controllers/api/v1/crypto/encrypted_messages_controller.rb
new file mode 100644
index 000000000..a67b03eb4
--- /dev/null
+++ b/app/controllers/api/v1/crypto/encrypted_messages_controller.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+class Api::V1::Crypto::EncryptedMessagesController < Api::BaseController
+  LIMIT = 80
+
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_current_device
+
+  before_action :set_encrypted_messages,    only: :index
+  after_action  :insert_pagination_headers, only: :index
+
+  def index
+    render json: @encrypted_messages, each_serializer: REST::EncryptedMessageSerializer
+  end
+
+  def clear
+    @current_device.encrypted_messages.up_to(params[:up_to_id]).delete_all
+    render_empty
+  end
+
+  private
+
+  def set_current_device
+    @current_device = Device.find_by!(access_token: doorkeeper_token)
+  end
+
+  def set_encrypted_messages
+    @encrypted_messages = @current_device.encrypted_messages.paginate_by_id(limit_param(LIMIT), params_slice(:max_id, :since_id, :min_id))
+  end
+
+  def insert_pagination_headers
+    set_pagination_headers(next_path, prev_path)
+  end
+
+  def next_path
+    api_v1_encrypted_messages_url pagination_params(max_id: pagination_max_id) if records_continue?
+  end
+
+  def prev_path
+    api_v1_encrypted_messages_url pagination_params(min_id: pagination_since_id) unless @encrypted_messages.empty?
+  end
+
+  def pagination_max_id
+    @encrypted_messages.last.id
+  end
+
+  def pagination_since_id
+    @encrypted_messages.first.id
+  end
+
+  def records_continue?
+    @encrypted_messages.size == limit_param(LIMIT)
+  end
+
+  def pagination_params(core_params)
+    params.slice(:limit).permit(:limit).merge(core_params)
+  end
+end
diff --git a/app/controllers/api/v1/crypto/keys/claims_controller.rb b/app/controllers/api/v1/crypto/keys/claims_controller.rb
new file mode 100644
index 000000000..34b21a380
--- /dev/null
+++ b/app/controllers/api/v1/crypto/keys/claims_controller.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+class Api::V1::Crypto::Keys::ClaimsController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_claim_results
+
+  def create
+    render json: @claim_results, each_serializer: REST::Keys::ClaimResultSerializer
+  end
+
+  private
+
+  def set_claim_results
+    @claim_results = devices.map { |device_params| ::Keys::ClaimService.new.call(current_account, device_params[:account_id], device_params[:device_id]) }.compact
+  end
+
+  def resource_params
+    params.permit(device: [:account_id, :device_id])
+  end
+
+  def devices
+    Array(resource_params[:device])
+  end
+end
diff --git a/app/controllers/api/v1/crypto/keys/counts_controller.rb b/app/controllers/api/v1/crypto/keys/counts_controller.rb
new file mode 100644
index 000000000..ffd7151b7
--- /dev/null
+++ b/app/controllers/api/v1/crypto/keys/counts_controller.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class Api::V1::Crypto::Keys::CountsController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_current_device
+
+  def show
+    render json: { one_time_keys: @current_device.one_time_keys.count }
+  end
+
+  private
+
+  def set_current_device
+    @current_device = Device.find_by!(access_token: doorkeeper_token)
+  end
+end
diff --git a/app/controllers/api/v1/crypto/keys/queries_controller.rb b/app/controllers/api/v1/crypto/keys/queries_controller.rb
new file mode 100644
index 000000000..0851d797d
--- /dev/null
+++ b/app/controllers/api/v1/crypto/keys/queries_controller.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+class Api::V1::Crypto::Keys::QueriesController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_accounts
+  before_action :set_query_results
+
+  def create
+    render json: @query_results, each_serializer: REST::Keys::QueryResultSerializer
+  end
+
+  private
+
+  def set_accounts
+    @accounts = Account.where(id: account_ids).includes(:devices)
+  end
+
+  def set_query_results
+    @query_results = @accounts.map { |account| ::Keys::QueryService.new.call(account) }.compact
+  end
+
+  def account_ids
+    Array(params[:id]).map(&:to_i)
+  end
+end
diff --git a/app/controllers/api/v1/crypto/keys/uploads_controller.rb b/app/controllers/api/v1/crypto/keys/uploads_controller.rb
new file mode 100644
index 000000000..fc4abf63b
--- /dev/null
+++ b/app/controllers/api/v1/crypto/keys/uploads_controller.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class Api::V1::Crypto::Keys::UploadsController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+
+  def create
+    device = Device.find_or_initialize_by(access_token: doorkeeper_token)
+
+    device.transaction do
+      device.account = current_account
+      device.update!(resource_params[:device])
+
+      if resource_params[:one_time_keys].present? && resource_params[:one_time_keys].is_a?(Enumerable)
+        resource_params[:one_time_keys].each do |one_time_key_params|
+          device.one_time_keys.create!(one_time_key_params)
+        end
+      end
+    end
+
+    render json: device, serializer: REST::Keys::DeviceSerializer
+  end
+
+  private
+
+  def resource_params
+    params.permit(device: [:device_id, :name, :fingerprint_key, :identity_key], one_time_keys: [:key_id, :key, :signature])
+  end
+end
diff --git a/app/controllers/statuses_controller.rb b/app/controllers/statuses_controller.rb
index d362b97dc..67a6cc2ec 100644
--- a/app/controllers/statuses_controller.rb
+++ b/app/controllers/statuses_controller.rb
@@ -42,7 +42,7 @@ class StatusesController < ApplicationController
 
   def activity
     expires_in 3.minutes, public: @status.distributable? && public_fetch_mode?
-    render_with_cache json: @status, content_type: 'application/activity+json', serializer: ActivityPub::ActivitySerializer, adapter: ActivityPub::Adapter
+    render_with_cache json: ActivityPub::ActivityPresenter.from_status(@status), content_type: 'application/activity+json', serializer: ActivityPub::ActivitySerializer, adapter: ActivityPub::Adapter
   end
 
   def embed
diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index 572b8087e..3509a6c40 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -2,6 +2,45 @@
 
 class ActivityPub::Activity::Create < ActivityPub::Activity
   def perform
+    case @object['type']
+    when 'EncryptedMessage'
+      create_encrypted_message
+    else
+      create_status
+    end
+  end
+
+  private
+
+  def create_encrypted_message
+    return reject_payload! if invalid_origin?(@object['id']) || @options[:delivered_to_account_id].blank?
+
+    target_account = Account.find(@options[:delivered_to_account_id])
+    target_device  = target_account.devices.find_by(device_id: @object.dig('to', 'deviceId'))
+
+    return if target_device.nil?
+
+    target_device.encrypted_messages.create!(
+      from_account: @account,
+      from_device_id: @object.dig('attributedTo', 'deviceId'),
+      type: @object['messageType'],
+      body: @object['cipherText'],
+      digest: @object.dig('digest', 'digestValue'),
+      message_franking: message_franking.to_token
+    )
+  end
+
+  def message_franking
+    MessageFranking.new(
+      hmac: @object.dig('digest', 'digestValue'),
+      original_franking: @object['messageFranking'],
+      source_account_id: @account.id,
+      target_account_id: @options[:delivered_to_account_id],
+      timestamp: Time.now.utc
+    )
+  end
+
+  def create_status
     return reject_payload! if unsupported_object_type? || invalid_origin?(@object['id']) || Tombstone.exists?(uri: @object['id']) || !related_to_local_activity?
 
     RedisLock.acquire(lock_options) do |lock|
@@ -23,8 +62,6 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     @status
   end
 
-  private
-
   def audience_to
     @object['to'] || @json['to']
   end
@@ -262,6 +299,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   def poll_vote!
     poll = replied_to_status.preloadable_poll
     already_voted = true
+
     RedisLock.acquire(poll_lock_options) do |lock|
       if lock.acquired?
         already_voted = poll.votes.where(account: @account).exists?
@@ -270,20 +308,24 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
         raise Mastodon::RaceConditionError
       end
     end
+
     increment_voters_count! unless already_voted
     ActivityPub::DistributePollUpdateWorker.perform_in(3.minutes, replied_to_status.id) unless replied_to_status.preloadable_poll.hide_totals?
   end
 
   def resolve_thread(status)
     return unless status.reply? && status.thread.nil? && Request.valid_url?(in_reply_to_uri)
+
     ThreadResolveWorker.perform_async(status.id, in_reply_to_uri)
   end
 
   def fetch_replies(status)
     collection = @object['replies']
     return if collection.nil?
+
     replies = ActivityPub::FetchRepliesService.new.call(status, collection, false)
     return unless replies.nil?
+
     uri = value_or_id(collection)
     ActivityPub::FetchRepliesWorker.perform_async(status.id, uri) unless uri.nil?
   end
@@ -291,6 +333,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   def conversation_from_uri(uri)
     return nil if uri.nil?
     return Conversation.find_by(id: OStatus::TagManager.instance.unique_tag_to_local_id(uri, 'Conversation')) if OStatus::TagManager.instance.local_id?(uri)
+
     begin
       Conversation.find_or_create_by!(uri: uri)
     rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique
@@ -404,6 +447,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
   def skip_download?
     return @skip_download if defined?(@skip_download)
+
     @skip_download ||= DomainBlock.reject_media?(@account.domain)
   end
 
@@ -436,11 +480,13 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
   def forward_for_reply
     return unless @json['signature'].present? && reply_to_local?
+
     ActivityPub::RawDistributionWorker.perform_async(Oj.dump(@json), replied_to_status.account_id, [@account.preferred_inbox_url])
   end
 
   def increment_voters_count!
     poll = replied_to_status.preloadable_poll
+
     unless poll.voters_count.nil?
       poll.voters_count = poll.voters_count + 1
       poll.save
diff --git a/app/lib/activitypub/adapter.rb b/app/lib/activitypub/adapter.rb
index 78138fb73..634ed29fa 100644
--- a/app/lib/activitypub/adapter.rb
+++ b/app/lib/activitypub/adapter.rb
@@ -22,6 +22,7 @@ class ActivityPub::Adapter < ActiveModelSerializers::Adapter::Base
     blurhash: { 'toot' => 'http://joinmastodon.org/ns#', 'blurhash' => 'toot:blurhash' },
     discoverable: { 'toot' => 'http://joinmastodon.org/ns#', 'discoverable' => 'toot:discoverable' },
     voters_count: { 'toot' => 'http://joinmastodon.org/ns#', 'votersCount' => 'toot:votersCount' },
+    olm: { 'toot' => 'http://joinmastodon.org/ns#', 'Device' => 'toot:Device', 'Ed25519Signature' => 'toot:Ed25519Signature', 'Ed25519Key' => 'toot:Ed25519Key', 'Curve25519Key' => 'toot:Curve25519Key', 'EncryptedMessage' => 'toot:EncryptedMessage', 'publicKeyBase64' => 'toot:publicKeyBase64', 'deviceId' => 'toot:deviceId', 'claim' => { '@type' => '@id', '@id' => 'toot:claim' }, 'fingerprintKey' => { '@type' => '@id', '@id' => 'toot:fingerprintKey' }, 'identityKey' => { '@type' => '@id', '@id' => 'toot:identityKey' }, 'devices' => { '@type' => '@id', '@id' => 'toot:devices' }, 'messageFranking' => 'toot:messageFranking', 'messageType' => 'toot:messageType', 'cipherText' => 'toot:cipherText' },
   }.freeze
 
   def self.default_key_transform
diff --git a/app/lib/inline_renderer.rb b/app/lib/inline_renderer.rb
index 27e334a4d..b70814748 100644
--- a/app/lib/inline_renderer.rb
+++ b/app/lib/inline_renderer.rb
@@ -19,6 +19,8 @@ class InlineRenderer
       serializer = REST::AnnouncementSerializer
     when :reaction
       serializer = REST::ReactionSerializer
+    when :encrypted_message
+      serializer = REST::EncryptedMessageSerializer
     else
       return
     end
diff --git a/app/models/account.rb b/app/models/account.rb
index ff7386aaf..6b7ebda9e 100644
--- a/app/models/account.rb
+++ b/app/models/account.rb
@@ -49,6 +49,7 @@
 #  hide_collections              :boolean
 #  avatar_storage_schema_version :integer
 #  header_storage_schema_version :integer
+#  devices_url                   :string
 #
 
 class Account < ApplicationRecord
diff --git a/app/models/concerns/account_associations.rb b/app/models/concerns/account_associations.rb
index 499edbf4e..cca3a17fa 100644
--- a/app/models/concerns/account_associations.rb
+++ b/app/models/concerns/account_associations.rb
@@ -9,6 +9,7 @@ module AccountAssociations
 
     # Identity proofs
     has_many :identity_proofs, class_name: 'AccountIdentityProof', dependent: :destroy, inverse_of: :account
+    has_many :devices, dependent: :destroy, inverse_of: :account
 
     # Timelines
     has_many :statuses, inverse_of: :account, dependent: :destroy
diff --git a/app/models/device.rb b/app/models/device.rb
new file mode 100644
index 000000000..97d0d2774
--- /dev/null
+++ b/app/models/device.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: devices
+#
+#  id              :bigint(8)        not null, primary key
+#  access_token_id :bigint(8)
+#  account_id      :bigint(8)
+#  device_id       :string           default(""), not null
+#  name            :string           default(""), not null
+#  fingerprint_key :text             default(""), not null
+#  identity_key    :text             default(""), not null
+#  created_at      :datetime         not null
+#  updated_at      :datetime         not null
+#
+
+class Device < ApplicationRecord
+  belongs_to :access_token, class_name: 'Doorkeeper::AccessToken'
+  belongs_to :account
+
+  has_many :one_time_keys, dependent: :destroy, inverse_of: :device
+  has_many :encrypted_messages, dependent: :destroy, inverse_of: :device
+
+  validates :name, :fingerprint_key, :identity_key, presence: true
+  validates :fingerprint_key, :identity_key, ed25519_key: true
+
+  before_save :invalidate_associations, if: -> { device_id_changed? || fingerprint_key_changed? || identity_key_changed? }
+
+  private
+
+  def invalidate_associations
+    one_time_keys.destroy_all
+    encrypted_messages.destroy_all
+  end
+end
diff --git a/app/models/encrypted_message.rb b/app/models/encrypted_message.rb
new file mode 100644
index 000000000..5e0aba434
--- /dev/null
+++ b/app/models/encrypted_message.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: encrypted_messages
+#
+#  id               :bigint(8)        not null, primary key
+#  device_id        :bigint(8)
+#  from_account_id  :bigint(8)
+#  from_device_id   :string           default(""), not null
+#  type             :integer          default(0), not null
+#  body             :text             default(""), not null
+#  digest           :text             default(""), not null
+#  message_franking :text             default(""), not null
+#  created_at       :datetime         not null
+#  updated_at       :datetime         not null
+#
+
+class EncryptedMessage < ApplicationRecord
+  self.inheritance_column = nil
+
+  include Paginable
+
+  scope :up_to, ->(id) { where(arel_table[:id].lteq(id)) }
+
+  belongs_to :device
+  belongs_to :from_account, class_name: 'Account'
+
+  around_create Mastodon::Snowflake::Callbacks
+
+  after_commit :push_to_streaming_api
+
+  private
+
+  def push_to_streaming_api
+    Rails.logger.info(streaming_channel)
+    Rails.logger.info(subscribed_to_timeline?)
+
+    return if destroyed? || !subscribed_to_timeline?
+
+    PushEncryptedMessageWorker.perform_async(id)
+  end
+
+  def subscribed_to_timeline?
+    Redis.current.exists("subscribed:#{streaming_channel}")
+  end
+
+  def streaming_channel
+    "timeline:#{device.account_id}:#{device.device_id}"
+  end
+end
diff --git a/app/models/message_franking.rb b/app/models/message_franking.rb
new file mode 100644
index 000000000..c72bd1cca
--- /dev/null
+++ b/app/models/message_franking.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class MessageFranking
+  attr_reader :hmac, :source_account_id, :target_account_id,
+              :timestamp, :original_franking
+
+  def initialize(attributes = {})
+    @hmac              = attributes[:hmac]
+    @source_account_id = attributes[:source_account_id]
+    @target_account_id = attributes[:target_account_id]
+    @timestamp         = attributes[:timestamp]
+    @original_franking = attributes[:original_franking]
+  end
+
+  def to_token
+    crypt = ActiveSupport::MessageEncryptor.new(SystemKey.current_key, serializer: Oj)
+    crypt.encrypt_and_sign(self)
+  end
+end
diff --git a/app/models/one_time_key.rb b/app/models/one_time_key.rb
new file mode 100644
index 000000000..8ada34824
--- /dev/null
+++ b/app/models/one_time_key.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: one_time_keys
+#
+#  id         :bigint(8)        not null, primary key
+#  device_id  :bigint(8)
+#  key_id     :string           default(""), not null
+#  key        :text             default(""), not null
+#  signature  :text             default(""), not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+
+class OneTimeKey < ApplicationRecord
+  belongs_to :device
+
+  validates :key_id, :key, :signature, presence: true
+  validates :key, ed25519_key: true
+  validates :signature, ed25519_signature: { message: :key, verify_key: ->(one_time_key) { one_time_key.device.fingerprint_key } }
+end
diff --git a/app/models/system_key.rb b/app/models/system_key.rb
new file mode 100644
index 000000000..f17db7c2d
--- /dev/null
+++ b/app/models/system_key.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: system_keys
+#
+#  id         :bigint(8)        not null, primary key
+#  key        :binary
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+class SystemKey < ApplicationRecord
+  ROTATION_PERIOD = 1.week.freeze
+
+  before_validation :set_key
+
+  scope :expired, ->(now = Time.now.utc) { where(arel_table[:created_at].lt(now - ROTATION_PERIOD * 3)) }
+
+  class << self
+    def current_key
+      previous_key = order(id: :asc).last
+
+      if previous_key && previous_key.created_at >= ROTATION_PERIOD.ago
+        previous_key.key
+      else
+        create.key
+      end
+    end
+  end
+
+  private
+
+  def set_key
+    return if key.present?
+
+    cipher = OpenSSL::Cipher.new('AES-256-GCM')
+    cipher.encrypt
+
+    self.key = cipher.random_key
+  end
+end
diff --git a/app/presenters/activitypub/activity_presenter.rb b/app/presenters/activitypub/activity_presenter.rb
new file mode 100644
index 000000000..5d174767f
--- /dev/null
+++ b/app/presenters/activitypub/activity_presenter.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+class ActivityPub::ActivityPresenter < ActiveModelSerializers::Model
+  attributes :id, :type, :actor, :published, :to, :cc, :virtual_object
+
+  class << self
+    def from_status(status)
+      new.tap do |presenter|
+        presenter.id        = ActivityPub::TagManager.instance.activity_uri_for(status)
+        presenter.type      = status.reblog? ? 'Announce' : 'Create'
+        presenter.actor     = ActivityPub::TagManager.instance.uri_for(status.account)
+        presenter.published = status.created_at
+        presenter.to        = ActivityPub::TagManager.instance.to(status)
+        presenter.cc        = ActivityPub::TagManager.instance.cc(status)
+
+        presenter.virtual_object = begin
+          if status.reblog?
+            if status.account == status.proper.account && status.proper.private_visibility? && status.local?
+              status.proper
+            else
+              ActivityPub::TagManager.instance.uri_for(status.proper)
+            end
+          else
+            status.proper
+          end
+        end
+      end
+    end
+
+    def from_encrypted_message(encrypted_message)
+      new.tap do |presenter|
+        presenter.id = ActivityPub::TagManager.instance.generate_uri_for(nil)
+        presenter.type = 'Create'
+        presenter.actor = ActivityPub::TagManager.instance.uri_for(encrypted_message.source_account)
+        presenter.published = Time.now.utc
+        presenter.to = ActivityPub::TagManager.instance.uri_for(encrypted_message.target_account)
+        presenter.virtual_object = encrypted_message
+      end
+    end
+  end
+end
diff --git a/app/serializers/activitypub/activity_serializer.rb b/app/serializers/activitypub/activity_serializer.rb
index d0edad786..5bdf53f03 100644
--- a/app/serializers/activitypub/activity_serializer.rb
+++ b/app/serializers/activitypub/activity_serializer.rb
@@ -1,52 +1,22 @@
 # frozen_string_literal: true
 
 class ActivityPub::ActivitySerializer < ActivityPub::Serializer
-  attributes :id, :type, :actor, :published, :to, :cc
-
-  has_one :proper, key: :object, serializer: ActivityPub::NoteSerializer, if: :serialize_object?
-
-  attribute :proper_uri, key: :object, unless: :serialize_object?
-  attribute :atom_uri, if: :announce?
-
-  def id
-    ActivityPub::TagManager.instance.activity_uri_for(object)
+  def self.serializer_for(model, options)
+    case model.class.name
+    when 'Status'
+      ActivityPub::NoteSerializer
+    when 'DeliverToDeviceService::EncryptedMessage'
+      ActivityPub::EncryptedMessageSerializer
+    else
+      super
+    end
   end
 
-  def type
-    announce? ? 'Announce' : 'Create'
-  end
+  attributes :id, :type, :actor, :published, :to, :cc
 
-  def actor
-    ActivityPub::TagManager.instance.uri_for(object.account)
-  end
+  has_one :virtual_object, key: :object
 
   def published
-    object.created_at.iso8601
-  end
-
-  def to
-    ActivityPub::TagManager.instance.to(object)
-  end
-
-  def cc
-    ActivityPub::TagManager.instance.cc(object)
-  end
-
-  def proper_uri
-    ActivityPub::TagManager.instance.uri_for(object.proper)
-  end
-
-  def atom_uri
-    OStatus::TagManager.instance.uri_for(object)
-  end
-
-  def announce?
-    object.reblog?
-  end
-
-  def serialize_object?
-    return true unless announce?
-    # Serialize private self-boosts of local toots
-    object.account == object.proper.account && object.proper.private_visibility? && object.local?
+    object.published.iso8601
   end
 end
diff --git a/app/serializers/activitypub/actor_serializer.rb b/app/serializers/activitypub/actor_serializer.rb
index aa64936a7..627d4446b 100644
--- a/app/serializers/activitypub/actor_serializer.rb
+++ b/app/serializers/activitypub/actor_serializer.rb
@@ -7,7 +7,7 @@ class ActivityPub::ActorSerializer < ActivityPub::Serializer
 
   context_extensions :manually_approves_followers, :featured, :also_known_as,
                      :moved_to, :property_value, :identity_proof,
-                     :discoverable
+                     :discoverable, :olm
 
   attributes :id, :type, :following, :followers,
              :inbox, :outbox, :featured,
@@ -20,6 +20,7 @@ class ActivityPub::ActorSerializer < ActivityPub::Serializer
   has_many :virtual_tags, key: :tag
   has_many :virtual_attachments, key: :attachment
 
+  attribute :devices, unless: :instance_actor?
   attribute :moved_to, if: :moved?
   attribute :also_known_as, if: :also_known_as?
 
@@ -38,7 +39,7 @@ class ActivityPub::ActorSerializer < ActivityPub::Serializer
   has_one :icon,  serializer: ActivityPub::ImageSerializer, if: :avatar_exists?
   has_one :image, serializer: ActivityPub::ImageSerializer, if: :header_exists?
 
-  delegate :moved?, to: :object
+  delegate :moved?, :instance_actor?, to: :object
 
   def id
     object.instance_actor? ? instance_actor_url : account_url(object)
@@ -68,6 +69,10 @@ class ActivityPub::ActorSerializer < ActivityPub::Serializer
     object.instance_actor? ? instance_actor_inbox_url : account_inbox_url(object)
   end
 
+  def devices
+    account_collection_url(object, :devices)
+  end
+
   def outbox
     account_outbox_url(object)
   end
diff --git a/app/serializers/activitypub/collection_serializer.rb b/app/serializers/activitypub/collection_serializer.rb
index da1ba735f..00c7b786a 100644
--- a/app/serializers/activitypub/collection_serializer.rb
+++ b/app/serializers/activitypub/collection_serializer.rb
@@ -2,9 +2,16 @@
 
 class ActivityPub::CollectionSerializer < ActivityPub::Serializer
   def self.serializer_for(model, options)
-    return ActivityPub::NoteSerializer if model.class.name == 'Status'
-    return ActivityPub::CollectionSerializer if model.class.name == 'ActivityPub::CollectionPresenter'
-    super
+    case model.class.name
+    when 'Status'
+      ActivityPub::NoteSerializer
+    when 'Device'
+      ActivityPub::DeviceSerializer
+    when 'ActivityPub::CollectionPresenter'
+      ActivityPub::CollectionSerializer
+    else
+      super
+    end
   end
 
   attribute :id, if: -> { object.id.present? }
diff --git a/app/serializers/activitypub/device_serializer.rb b/app/serializers/activitypub/device_serializer.rb
new file mode 100644
index 000000000..5f0fdc8af
--- /dev/null
+++ b/app/serializers/activitypub/device_serializer.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+class ActivityPub::DeviceSerializer < ActivityPub::Serializer
+  context_extensions :olm
+
+  include RoutingHelper
+
+  class FingerprintKeySerializer < ActivityPub::Serializer
+    attributes :type, :public_key_base64
+
+    def type
+      'Ed25519Key'
+    end
+
+    def public_key_base64
+      object.fingerprint_key
+    end
+  end
+
+  class IdentityKeySerializer < ActivityPub::Serializer
+    attributes :type, :public_key_base64
+
+    def type
+      'Curve25519Key'
+    end
+
+    def public_key_base64
+      object.identity_key
+    end
+  end
+
+  attributes :device_id, :type, :name, :claim
+
+  has_one :fingerprint_key, serializer: FingerprintKeySerializer
+  has_one :identity_key, serializer: IdentityKeySerializer
+
+  def type
+    'Device'
+  end
+
+  def claim
+    account_claim_url(object.account, id: object.device_id)
+  end
+
+  def fingerprint_key
+    object
+  end
+
+  def identity_key
+    object
+  end
+end
diff --git a/app/serializers/activitypub/encrypted_message_serializer.rb b/app/serializers/activitypub/encrypted_message_serializer.rb
new file mode 100644
index 000000000..3c525d23e
--- /dev/null
+++ b/app/serializers/activitypub/encrypted_message_serializer.rb
@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+class ActivityPub::EncryptedMessageSerializer < ActivityPub::Serializer
+  context :security
+
+  context_extensions :olm
+
+  class DeviceSerializer < ActivityPub::Serializer
+    attributes :type, :device_id
+
+    def type
+      'Device'
+    end
+
+    def device_id
+      object
+    end
+  end
+
+  class DigestSerializer < ActivityPub::Serializer
+    attributes :type, :digest_algorithm, :digest_value
+
+    def type
+      'Digest'
+    end
+
+    def digest_algorithm
+      'http://www.w3.org/2000/09/xmldsig#hmac-sha256'
+    end
+
+    def digest_value
+      object
+    end
+  end
+
+  attributes :type, :message_type, :cipher_text, :message_franking
+
+  has_one :attributed_to, serializer: DeviceSerializer
+  has_one :to, serializer: DeviceSerializer
+  has_one :digest, serializer: DigestSerializer
+
+  def type
+    'EncryptedMessage'
+  end
+
+  def attributed_to
+    object.source_device.device_id
+  end
+
+  def to
+    object.target_device_id
+  end
+
+  def message_type
+    object.type
+  end
+
+  def cipher_text
+    object.body
+  end
+end
diff --git a/app/serializers/activitypub/one_time_key_serializer.rb b/app/serializers/activitypub/one_time_key_serializer.rb
new file mode 100644
index 000000000..5932eb5b5
--- /dev/null
+++ b/app/serializers/activitypub/one_time_key_serializer.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+class ActivityPub::OneTimeKeySerializer < ActivityPub::Serializer
+  context :security
+
+  context_extensions :olm
+
+  class SignatureSerializer < ActivityPub::Serializer
+    attributes :type, :signature_value
+
+    def type
+      'Ed25519Signature'
+    end
+
+    def signature_value
+      object.signature
+    end
+  end
+
+  attributes :key_id, :type, :public_key_base64
+
+  has_one :signature, serializer: SignatureSerializer
+
+  def type
+    'Curve25519Key'
+  end
+
+  def public_key_base64
+    object.key
+  end
+
+  def signature
+    object
+  end
+end
diff --git a/app/serializers/activitypub/outbox_serializer.rb b/app/serializers/activitypub/outbox_serializer.rb
index 48fbad0fd..4f4f950a5 100644
--- a/app/serializers/activitypub/outbox_serializer.rb
+++ b/app/serializers/activitypub/outbox_serializer.rb
@@ -2,7 +2,14 @@
 
 class ActivityPub::OutboxSerializer < ActivityPub::CollectionSerializer
   def self.serializer_for(model, options)
-    return ActivityPub::ActivitySerializer if model.is_a?(Status)
-    super
+    if model.class.name == 'ActivityPub::ActivityPresenter'
+      ActivityPub::ActivitySerializer
+    else
+      super
+    end
+  end
+
+  def items
+    object.items.map { |status| ActivityPub::ActivityPresenter.from_status(status) }
   end
 end
diff --git a/app/serializers/activitypub/undo_announce_serializer.rb b/app/serializers/activitypub/undo_announce_serializer.rb
index 6758af679..a925efc18 100644
--- a/app/serializers/activitypub/undo_announce_serializer.rb
+++ b/app/serializers/activitypub/undo_announce_serializer.rb
@@ -3,7 +3,7 @@
 class ActivityPub::UndoAnnounceSerializer < ActivityPub::Serializer
   attributes :id, :type, :actor, :to
 
-  has_one :object, serializer: ActivityPub::ActivitySerializer
+  has_one :virtual_object, key: :object, serializer: ActivityPub::ActivitySerializer
 
   def id
     [ActivityPub::TagManager.instance.uri_for(object.account), '#announces/', object.id, '/undo'].join
@@ -20,4 +20,8 @@ class ActivityPub::UndoAnnounceSerializer < ActivityPub::Serializer
   def to
     [ActivityPub::TagManager::COLLECTIONS[:public]]
   end
+
+  def virtual_object
+    ActivityPub::ActivityPresenter.from_status(object)
+  end
 end
diff --git a/app/serializers/rest/encrypted_message_serializer.rb b/app/serializers/rest/encrypted_message_serializer.rb
new file mode 100644
index 000000000..61ebc74fa
--- /dev/null
+++ b/app/serializers/rest/encrypted_message_serializer.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class REST::EncryptedMessageSerializer < ActiveModel::Serializer
+  attributes :id, :account_id, :device_id,
+             :type, :body, :digest, :message_franking
+
+  def id
+    object.id.to_s
+  end
+
+  def account_id
+    object.from_account_id.to_s
+  end
+
+  def device_id
+    object.from_device_id
+  end
+end
diff --git a/app/serializers/rest/keys/claim_result_serializer.rb b/app/serializers/rest/keys/claim_result_serializer.rb
new file mode 100644
index 000000000..145044f55
--- /dev/null
+++ b/app/serializers/rest/keys/claim_result_serializer.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class REST::Keys::ClaimResultSerializer < ActiveModel::Serializer
+  attributes :account_id, :device_id, :key_id, :key, :signature
+
+  def account_id
+    object.account.id.to_s
+  end
+end
diff --git a/app/serializers/rest/keys/device_serializer.rb b/app/serializers/rest/keys/device_serializer.rb
new file mode 100644
index 000000000..f9b821b79
--- /dev/null
+++ b/app/serializers/rest/keys/device_serializer.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+class REST::Keys::DeviceSerializer < ActiveModel::Serializer
+  attributes :device_id, :name, :identity_key,
+             :fingerprint_key
+end
diff --git a/app/serializers/rest/keys/query_result_serializer.rb b/app/serializers/rest/keys/query_result_serializer.rb
new file mode 100644
index 000000000..8f8bdde28
--- /dev/null
+++ b/app/serializers/rest/keys/query_result_serializer.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class REST::Keys::QueryResultSerializer < ActiveModel::Serializer
+  attributes :account_id
+
+  has_many :devices, serializer: REST::Keys::DeviceSerializer
+
+  def account_id
+    object.account.id.to_s
+  end
+end
diff --git a/app/services/activitypub/process_account_service.rb b/app/services/activitypub/process_account_service.rb
index 7b4c53d50..f4276cece 100644
--- a/app/services/activitypub/process_account_service.rb
+++ b/app/services/activitypub/process_account_service.rb
@@ -76,6 +76,7 @@ class ActivityPub::ProcessAccountService < BaseService
     @account.shared_inbox_url        = (@json['endpoints'].is_a?(Hash) ? @json['endpoints']['sharedInbox'] : @json['sharedInbox']) || ''
     @account.followers_url           = @json['followers'] || ''
     @account.featured_collection_url = @json['featured'] || ''
+    @account.devices_url             = @json['devices'] || ''
     @account.url                     = url || @uri
     @account.uri                     = @uri
     @account.display_name            = @json['name'] || ''
diff --git a/app/services/backup_service.rb b/app/services/backup_service.rb
index 896699324..6a1575616 100644
--- a/app/services/backup_service.rb
+++ b/app/services/backup_service.rb
@@ -22,7 +22,7 @@ class BackupService < BaseService
 
     account.statuses.with_includes.reorder(nil).find_in_batches do |statuses|
       statuses.each do |status|
-        item = serialize_payload(status, ActivityPub::ActivitySerializer, signer: @account)
+        item = serialize_payload(ActivityPub::ActivityPresenter.from_status(status), ActivityPub::ActivitySerializer, signer: @account)
         item.delete(:'@context')
 
         unless item[:type] == 'Announce' || item[:object][:attachment].blank?
diff --git a/app/services/deliver_to_device_service.rb b/app/services/deliver_to_device_service.rb
new file mode 100644
index 000000000..71711945c
--- /dev/null
+++ b/app/services/deliver_to_device_service.rb
@@ -0,0 +1,78 @@
+# frozen_string_literal: true
+
+class DeliverToDeviceService < BaseService
+  include Payloadable
+
+  class EncryptedMessage < ActiveModelSerializers::Model
+    attributes :source_account, :target_account, :source_device,
+               :target_device_id, :type, :body, :digest,
+               :message_franking
+  end
+
+  def call(source_account, source_device, options = {})
+    @source_account   = source_account
+    @source_device    = source_device
+    @target_account   = Account.find(options[:account_id])
+    @target_device_id = options[:device_id]
+    @body             = options[:body]
+    @type             = options[:type]
+    @hmac             = options[:hmac]
+
+    set_message_franking!
+
+    if @target_account.local?
+      deliver_to_local!
+    else
+      deliver_to_remote!
+    end
+  end
+
+  private
+
+  def set_message_franking!
+    @message_franking = message_franking.to_token
+  end
+
+  def deliver_to_local!
+    target_device = @target_account.devices.find_by!(device_id: @target_device_id)
+
+    target_device.encrypted_messages.create!(
+      from_account: @source_account,
+      from_device_id: @source_device.device_id,
+      type: @type,
+      body: @body,
+      digest: @hmac,
+      message_franking: @message_franking
+    )
+  end
+
+  def deliver_to_remote!
+    ActivityPub::DeliveryWorker.perform_async(
+      Oj.dump(serialize_payload(ActivityPub::ActivityPresenter.from_encrypted_message(encrypted_message), ActivityPub::ActivitySerializer)),
+      @source_account.id,
+      @target_account.inbox_url
+    )
+  end
+
+  def message_franking
+    MessageFranking.new(
+      source_account_id: @source_account.id,
+      target_account_id: @target_account.id,
+      hmac: @hmac,
+      timestamp: Time.now.utc
+    )
+  end
+
+  def encrypted_message
+    EncryptedMessage.new(
+      source_account: @source_account,
+      target_account: @target_account,
+      source_device: @source_device,
+      target_device_id: @target_device_id,
+      type: @type,
+      body: @body,
+      digest: @hmac,
+      message_franking: @message_franking
+    )
+  end
+end
diff --git a/app/services/keys/claim_service.rb b/app/services/keys/claim_service.rb
new file mode 100644
index 000000000..672119130
--- /dev/null
+++ b/app/services/keys/claim_service.rb
@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+class Keys::ClaimService < BaseService
+  HEADERS = { 'Content-Type' => 'application/activity+json' }.freeze
+
+  class Result < ActiveModelSerializers::Model
+    attributes :account, :device_id, :key_id,
+               :key, :signature
+
+    def initialize(account, device_id, key_attributes = {})
+      @account   = account
+      @device_id = device_id
+      @key_id    = key_attributes[:key_id]
+      @key       = key_attributes[:key]
+      @signature = key_attributes[:signature]
+    end
+  end
+
+  def call(source_account, target_account_id, device_id)
+    @source_account = source_account
+    @target_account = Account.find(target_account_id)
+    @device_id      = device_id
+
+    if @target_account.local?
+      claim_local_key!
+    else
+      claim_remote_key!
+    end
+  rescue ActiveRecord::RecordNotFound
+    nil
+  end
+
+  private
+
+  def claim_local_key!
+    device = @target_account.devices.find_by(device_id: @device_id)
+    key    = nil
+
+    ApplicationRecord.transaction do
+      key = device.one_time_keys.order(Arel.sql('random()')).first!
+      key.destroy!
+    end
+
+    @result = Result.new(@target_account, @device_id, key)
+  end
+
+  def claim_remote_key!
+    query_result = QueryService.new.call(@target_account)
+    device       = query_result.find(@device_id)
+
+    return unless device.present? && device.valid_claim_url?
+
+    json = fetch_resource_with_post(device.claim_url)
+
+    return unless json.present? && json['publicKeyBase64'].present?
+
+    @result = Result.new(@target_account, @device_id, key_id: json['id'], key: json['publicKeyBase64'], signature: json.dig('signature', 'signatureValue'))
+  rescue HTTP::Error, OpenSSL::SSL::SSLError, Mastodon::Error => e
+    Rails.logger.debug "Claiming one-time key for #{@target_account.acct}:#{@device_id} failed: #{e}"
+    nil
+  end
+
+  def fetch_resource_with_post(uri)
+    build_post_request(uri).perform do |response|
+      raise Mastodon::UnexpectedResponseError, response unless response_successful?(response) || response_error_unsalvageable?(response)
+
+      body_to_json(response.body_with_limit) if response.code == 200
+    end
+  end
+
+  def build_post_request(uri)
+    Request.new(:post, uri).tap do |request|
+      request.on_behalf_of(@source_account, :uri)
+      request.add_headers(HEADERS)
+    end
+  end
+end
diff --git a/app/services/keys/query_service.rb b/app/services/keys/query_service.rb
new file mode 100644
index 000000000..286fbd834
--- /dev/null
+++ b/app/services/keys/query_service.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+class Keys::QueryService < BaseService
+  include JsonLdHelper
+
+  class Result < ActiveModelSerializers::Model
+    attributes :account, :devices
+
+    def initialize(account, devices)
+      @account = account
+      @devices = devices || []
+    end
+
+    def find(device_id)
+      @devices.find { |device| device.device_id == device_id }
+    end
+  end
+
+  class Device < ActiveModelSerializers::Model
+    attributes :device_id, :name, :identity_key, :fingerprint_key
+
+    def initialize(attributes = {})
+      @device_id       = attributes[:device_id]
+      @name            = attributes[:name]
+      @identity_key    = attributes[:identity_key]
+      @fingerprint_key = attributes[:fingerprint_key]
+      @claim_url       = attributes[:claim_url]
+    end
+
+    def valid_claim_url?
+      return false if @claim_url.blank?
+
+      begin
+        parsed_url = Addressable::URI.parse(@claim_url).normalize
+      rescue Addressable::URI::InvalidURIError
+        return false
+      end
+
+      %w(http https).include?(parsed_url.scheme) && parsed_url.host.present?
+    end
+  end
+
+  def call(account)
+    @account = account
+
+    if @account.local?
+      query_local_devices!
+    else
+      query_remote_devices!
+    end
+
+    Result.new(@account, @devices)
+  end
+
+  private
+
+  def query_local_devices!
+    @devices = @account.devices.map { |device| Device.new(device) }
+  end
+
+  def query_remote_devices!
+    return if @account.devices_url.blank?
+
+    json = fetch_resource(@account.devices_url)
+
+    return if json['items'].blank?
+
+    @devices = json['items'].map do |device|
+      Device.new(device_id: device['id'], name: device['name'], identity_key: device.dig('identityKey', 'publicKeyBase64'), fingerprint_key: device.dig('fingerprintKey', 'publicKeyBase64'), claim_url: device['claim'])
+    end
+  rescue HTTP::Error, OpenSSL::SSL::SSLError, Mastodon::Error => e
+    Rails.logger.debug "Querying devices for #{@account.acct} failed: #{e}"
+    nil
+  end
+end
diff --git a/app/services/process_mentions_service.rb b/app/services/process_mentions_service.rb
index b2d868165..3822b7dc5 100644
--- a/app/services/process_mentions_service.rb
+++ b/app/services/process_mentions_service.rb
@@ -65,7 +65,7 @@ class ProcessMentionsService < BaseService
 
   def activitypub_json
     return @activitypub_json if defined?(@activitypub_json)
-    @activitypub_json = Oj.dump(serialize_payload(@status, ActivityPub::ActivitySerializer, signer: @status.account))
+    @activitypub_json = Oj.dump(serialize_payload(ActivityPub::ActivityPresenter.from_status(@status), ActivityPub::ActivitySerializer, signer: @status.account))
   end
 
   def resolve_account_service
diff --git a/app/services/reblog_service.rb b/app/services/reblog_service.rb
index 4b5ae9492..6866d2fac 100644
--- a/app/services/reblog_service.rb
+++ b/app/services/reblog_service.rb
@@ -60,6 +60,6 @@ class ReblogService < BaseService
   end
 
   def build_json(reblog)
-    Oj.dump(serialize_payload(reblog, ActivityPub::ActivitySerializer, signer: reblog.account))
+    Oj.dump(serialize_payload(ActivityPub::ActivityPresenter.from_status(reblog), ActivityPub::ActivitySerializer, signer: reblog.account))
   end
 end
diff --git a/app/validators/ed25519_key_validator.rb b/app/validators/ed25519_key_validator.rb
new file mode 100644
index 000000000..00a448d5a
--- /dev/null
+++ b/app/validators/ed25519_key_validator.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class Ed25519KeyValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    return if value.blank?
+
+    key = Base64.decode64(value)
+
+    record.errors[attribute] << I18n.t('crypto.errors.invalid_key') unless verified?(key)
+  end
+
+  private
+
+  def verified?(key)
+    Ed25519.validate_key_bytes(key)
+  rescue ArgumentError
+    false
+  end
+end
diff --git a/app/validators/ed25519_signature_validator.rb b/app/validators/ed25519_signature_validator.rb
new file mode 100644
index 000000000..77a21b837
--- /dev/null
+++ b/app/validators/ed25519_signature_validator.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class Ed25519SignatureValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    return if value.blank?
+
+    verify_key = Ed25519::VerifyKey.new(Base64.decode64(option_to_value(record, :verify_key)))
+    signature  = Base64.decode64(value)
+    message    = option_to_value(record, :message)
+
+    record.errors[attribute] << I18n.t('crypto.errors.invalid_signature') unless verified?(verify_key, signature, message)
+  end
+
+  private
+
+  def verified?(verify_key, signature, message)
+    verify_key.verify(signature, message)
+  rescue Ed25519::VerifyError, ArgumentError
+    false
+  end
+
+  def option_to_value(record, key)
+    if options[key].is_a?(Proc)
+      options[key].call(record)
+    else
+      record.public_send(options[key])
+    end
+  end
+end
diff --git a/app/workers/activitypub/distribution_worker.rb b/app/workers/activitypub/distribution_worker.rb
index 11b6a6111..e4997ba0e 100644
--- a/app/workers/activitypub/distribution_worker.rb
+++ b/app/workers/activitypub/distribution_worker.rb
@@ -43,7 +43,7 @@ class ActivityPub::DistributionWorker
   end
 
   def payload
-    @payload ||= Oj.dump(serialize_payload(@status, ActivityPub::ActivitySerializer, signer: @account))
+    @payload ||= Oj.dump(serialize_payload(ActivityPub::ActivityPresenter.from_status(@status), ActivityPub::ActivitySerializer, signer: @account))
   end
 
   def relay!
diff --git a/app/workers/activitypub/reply_distribution_worker.rb b/app/workers/activitypub/reply_distribution_worker.rb
index 1ff8a657e..d4d0148ac 100644
--- a/app/workers/activitypub/reply_distribution_worker.rb
+++ b/app/workers/activitypub/reply_distribution_worker.rb
@@ -29,6 +29,6 @@ class ActivityPub::ReplyDistributionWorker
   end
 
   def payload
-    @payload ||= Oj.dump(serialize_payload(@status, ActivityPub::ActivitySerializer, signer: @status.account))
+    @payload ||= Oj.dump(serialize_payload(ActivityPub::ActivityPresenter.from_status(@status), ActivityPub::ActivitySerializer, signer: @status.account))
   end
 end
diff --git a/app/workers/push_conversation_worker.rb b/app/workers/push_conversation_worker.rb
index 16f538215..aa858f715 100644
--- a/app/workers/push_conversation_worker.rb
+++ b/app/workers/push_conversation_worker.rb
@@ -2,13 +2,14 @@
 
 class PushConversationWorker
   include Sidekiq::Worker
+  include Redisable
 
   def perform(conversation_account_id)
     conversation = AccountConversation.find(conversation_account_id)
     message      = InlineRenderer.render(conversation, conversation.account, :conversation)
     timeline_id  = "timeline:direct:#{conversation.account_id}"
 
-    Redis.current.publish(timeline_id, Oj.dump(event: :conversation, payload: message, queued_at: (Time.now.to_f * 1000.0).to_i))
+    redis.publish(timeline_id, Oj.dump(event: :conversation, payload: message, queued_at: (Time.now.to_f * 1000.0).to_i))
   rescue ActiveRecord::RecordNotFound
     true
   end
diff --git a/app/workers/push_encrypted_message_worker.rb b/app/workers/push_encrypted_message_worker.rb
new file mode 100644
index 000000000..031230172
--- /dev/null
+++ b/app/workers/push_encrypted_message_worker.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+class PushEncryptedMessageWorker
+  include Sidekiq::Worker
+  include Redisable
+
+  def perform(encrypted_message_id)
+    encrypted_message = EncryptedMessage.find(encrypted_message_id)
+    message           = InlineRenderer.render(encrypted_message, nil, :encrypted_message)
+    timeline_id       = "timeline:#{encrypted_message.device.account_id}:#{encrypted_message.device.device_id}"
+
+    redis.publish(timeline_id, Oj.dump(event: :encrypted_message, payload: message, queued_at: (Time.now.to_f * 1000.0).to_i))
+  rescue ActiveRecord::RecordNotFound
+    true
+  end
+end
diff --git a/app/workers/scheduler/doorkeeper_cleanup_scheduler.rb b/app/workers/scheduler/doorkeeper_cleanup_scheduler.rb
index 94788a85b..bb9dd49ca 100644
--- a/app/workers/scheduler/doorkeeper_cleanup_scheduler.rb
+++ b/app/workers/scheduler/doorkeeper_cleanup_scheduler.rb
@@ -8,5 +8,6 @@ class Scheduler::DoorkeeperCleanupScheduler
   def perform
     Doorkeeper::AccessToken.where('revoked_at IS NOT NULL').where('revoked_at < NOW()').delete_all
     Doorkeeper::AccessGrant.where('revoked_at IS NOT NULL').where('revoked_at < NOW()').delete_all
+    SystemKey.expired.delete_all
   end
 end
diff --git a/config/brakeman.ignore b/config/brakeman.ignore
index 7e3828f7e..baa993c78 100644
--- a/config/brakeman.ignore
+++ b/config/brakeman.ignore
@@ -1,33 +1,13 @@
 {
   "ignored_warnings": [
     {
-      "warning_type": "Mass Assignment",
-      "warning_code": 105,
-      "fingerprint": "0117d2be5947ea4e4fbed9c15f23c6615b12c6892973411820c83d079808819d",
-      "check_name": "PermitAttributes",
-      "message": "Potentially dangerous key allowed for mass assignment",
-      "file": "app/controllers/api/v1/search_controller.rb",
-      "line": 30,
-      "link": "https://brakemanscanner.org/docs/warning_types/mass_assignment/",
-      "code": "params.permit(:type, :offset, :min_id, :max_id, :account_id)",
-      "render_path": null,
-      "location": {
-        "type": "method",
-        "class": "Api::V1::SearchController",
-        "method": "search_params"
-      },
-      "user_input": ":account_id",
-      "confidence": "High",
-      "note": ""
-    },
-    {
       "warning_type": "SQL Injection",
       "warning_code": 0,
       "fingerprint": "04dbbc249b989db2e0119bbb0f59c9818e12889d2b97c529cdc0b1526002ba4b",
       "check_name": "SQL",
       "message": "Possible SQL injection",
       "file": "app/models/report.rb",
-      "line": 90,
+      "line": 112,
       "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
       "code": "Admin::ActionLog.from(\"(#{[Admin::ActionLog.where(:target_type => \"Report\", :target_id => id, :created_at => ((created_at..updated_at))).unscope(:order), Admin::ActionLog.where(:target_type => \"Account\", :target_id => target_account_id, :created_at => ((created_at..updated_at))).unscope(:order), Admin::ActionLog.where(:target_type => \"Status\", :target_id => status_ids, :created_at => ((created_at..updated_at))).unscope(:order)].map do\n \"(#{query.to_sql})\"\n end.join(\" UNION ALL \")}) AS admin_action_logs\")",
       "render_path": null,
@@ -47,7 +27,7 @@
       "check_name": "SQL",
       "message": "Possible SQL injection",
       "file": "app/models/status.rb",
-      "line": 87,
+      "line": 100,
       "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
       "code": "result.joins(\"INNER JOIN statuses_tags t#{id} ON t#{id}.status_id = statuses.id AND t#{id}.tag_id = #{id}\")",
       "render_path": null,
@@ -61,39 +41,62 @@
       "note": ""
     },
     {
-      "warning_type": "Mass Assignment",
-      "warning_code": 105,
-      "fingerprint": "28d81cc22580ef76e912b077b245f353499aa27b3826476667224c00227af2a9",
-      "check_name": "PermitAttributes",
-      "message": "Potentially dangerous key allowed for mass assignment",
-      "file": "app/controllers/admin/reports_controller.rb",
-      "line": 56,
-      "link": "https://brakemanscanner.org/docs/warning_types/mass_assignment/",
-      "code": "params.permit(:account_id, :resolved, :target_account_id)",
-      "render_path": null,
+      "warning_type": "Dynamic Render Path",
+      "warning_code": 15,
+      "fingerprint": "20a660939f2bbf8c665e69f2844031c0564524689a9570a0091ed94846212020",
+      "check_name": "Render",
+      "message": "Render path contains parameter value",
+      "file": "app/views/admin/action_logs/index.html.haml",
+      "line": 26,
+      "link": "https://brakemanscanner.org/docs/warning_types/dynamic_render_path/",
+      "code": "render(action => Admin::ActionLogFilter.new(filter_params).results.page(params[:page]), {})",
+      "render_path": [
+        {
+          "type": "controller",
+          "class": "Admin::ActionLogsController",
+          "method": "index",
+          "line": 8,
+          "file": "app/controllers/admin/action_logs_controller.rb",
+          "rendered": {
+            "name": "admin/action_logs/index",
+            "file": "app/views/admin/action_logs/index.html.haml"
+          }
+        }
+      ],
       "location": {
-        "type": "method",
-        "class": "Admin::ReportsController",
-        "method": "filter_params"
+        "type": "template",
+        "template": "admin/action_logs/index"
       },
-      "user_input": ":account_id",
-      "confidence": "High",
+      "user_input": "params[:page]",
+      "confidence": "Weak",
       "note": ""
     },
     {
       "warning_type": "Dynamic Render Path",
       "warning_code": 15,
-      "fingerprint": "4b6a895e2805578d03ceedbe1d469cc75a0c759eba093722523edb4b8683c873",
+      "fingerprint": "371fe16dc4c9d6ab08a20437d65be4825776107a67c38f6d4780a9c703cd44a5",
       "check_name": "Render",
       "message": "Render path contains parameter value",
-      "file": "app/views/admin/action_logs/index.html.haml",
-      "line": 4,
+      "file": "app/views/admin/email_domain_blocks/index.html.haml",
+      "line": 17,
       "link": "https://brakemanscanner.org/docs/warning_types/dynamic_render_path/",
-      "code": "render(action => Admin::ActionLog.page(params[:page]), {})",
-      "render_path": [{"type":"controller","class":"Admin::ActionLogsController","method":"index","line":7,"file":"app/controllers/admin/action_logs_controller.rb","rendered":{"name":"admin/action_logs/index","file":"/home/eugr/Projects/mastodon/app/views/admin/action_logs/index.html.haml"}}],
+      "code": "render(action => EmailDomainBlock.where(:parent_id => nil).includes(:children).order(:id => :desc).page(params[:page]), {})",
+      "render_path": [
+        {
+          "type": "controller",
+          "class": "Admin::EmailDomainBlocksController",
+          "method": "index",
+          "line": 10,
+          "file": "app/controllers/admin/email_domain_blocks_controller.rb",
+          "rendered": {
+            "name": "admin/email_domain_blocks/index",
+            "file": "app/views/admin/email_domain_blocks/index.html.haml"
+          }
+        }
+      ],
       "location": {
         "type": "template",
-        "template": "admin/action_logs/index"
+        "template": "admin/email_domain_blocks/index"
       },
       "user_input": "params[:page]",
       "confidence": "Weak",
@@ -106,7 +109,7 @@
       "check_name": "Redirect",
       "message": "Possible unprotected redirect",
       "file": "app/controllers/remote_interaction_controller.rb",
-      "line": 21,
+      "line": 24,
       "link": "https://brakemanscanner.org/docs/warning_types/redirect/",
       "code": "redirect_to(RemoteFollow.new(resource_params).interact_address_for(Status.find(params[:id])))",
       "render_path": null,
@@ -120,32 +123,13 @@
       "note": ""
     },
     {
-      "warning_type": "Dynamic Render Path",
-      "warning_code": 15,
-      "fingerprint": "67afc0d5f7775fa5bd91d1912e1b5505aeedef61876347546fa20f92fd6915e6",
-      "check_name": "Render",
-      "message": "Render path contains parameter value",
-      "file": "app/views/stream_entries/embed.html.haml",
-      "line": 3,
-      "link": "https://brakemanscanner.org/docs/warning_types/dynamic_render_path/",
-      "code": "render(action => \"stream_entries/#{Account.find_local!(params[:account_username]).statuses.find(params[:id]).stream_entry.activity_type.downcase}\", { Account.find_local!(params[:account_username]).statuses.find(params[:id]).stream_entry.activity_type.downcase.to_sym => Account.find_local!(params[:account_username]).statuses.find(params[:id]).stream_entry.activity, :centered => true, :autoplay => ActiveModel::Type::Boolean.new.cast(params[:autoplay]) })",
-      "render_path": [{"type":"controller","class":"StatusesController","method":"embed","line":63,"file":"app/controllers/statuses_controller.rb","rendered":{"name":"stream_entries/embed","file":"/home/eugr/Projects/mastodon/app/views/stream_entries/embed.html.haml"}}],
-      "location": {
-        "type": "template",
-        "template": "stream_entries/embed"
-      },
-      "user_input": "params[:id]",
-      "confidence": "Weak",
-      "note": ""
-    },
-    {
       "warning_type": "SQL Injection",
       "warning_code": 0,
       "fingerprint": "6f075c1484908e3ec9bed21ab7cf3c7866be8da3881485d1c82e13093aefcbd7",
       "check_name": "SQL",
       "message": "Possible SQL injection",
       "file": "app/models/status.rb",
-      "line": 92,
+      "line": 105,
       "link": "https://brakemanscanner.org/docs/warning_types/sql_injection/",
       "code": "result.joins(\"LEFT OUTER JOIN statuses_tags t#{id} ON t#{id}.status_id = statuses.id AND t#{id}.tag_id = #{id}\")",
       "render_path": null,
@@ -159,22 +143,43 @@
       "note": ""
     },
     {
-      "warning_type": "Dynamic Render Path",
-      "warning_code": 15,
-      "fingerprint": "8d843713d99e8403f7992f3e72251b633817cf9076ffcbbad5613859d2bbc127",
-      "check_name": "Render",
-      "message": "Render path contains parameter value",
-      "file": "app/views/admin/custom_emojis/index.html.haml",
-      "line": 45,
-      "link": "https://brakemanscanner.org/docs/warning_types/dynamic_render_path/",
-      "code": "render(action => filtered_custom_emojis.eager_load(:local_counterpart).page(params[:page]), {})",
-      "render_path": [{"type":"controller","class":"Admin::CustomEmojisController","method":"index","line":11,"file":"app/controllers/admin/custom_emojis_controller.rb","rendered":{"name":"admin/custom_emojis/index","file":"/home/eugr/Projects/mastodon/app/views/admin/custom_emojis/index.html.haml"}}],
+      "warning_type": "Mass Assignment",
+      "warning_code": 105,
+      "fingerprint": "7631e93d0099506e7c3e5c91ba8d88523b00a41a0834ae30031a5a4e8bb3020a",
+      "check_name": "PermitAttributes",
+      "message": "Potentially dangerous key allowed for mass assignment",
+      "file": "app/controllers/api/v2/search_controller.rb",
+      "line": 28,
+      "link": "https://brakemanscanner.org/docs/warning_types/mass_assignment/",
+      "code": "params.permit(:type, :offset, :min_id, :max_id, :account_id)",
+      "render_path": null,
       "location": {
-        "type": "template",
-        "template": "admin/custom_emojis/index"
+        "type": "method",
+        "class": "Api::V2::SearchController",
+        "method": "search_params"
       },
-      "user_input": "params[:page]",
-      "confidence": "Weak",
+      "user_input": ":account_id",
+      "confidence": "High",
+      "note": ""
+    },
+    {
+      "warning_type": "Mass Assignment",
+      "warning_code": 105,
+      "fingerprint": "8f63dec68951d9bcf7eddb15af9392b2e1333003089c41fb76688dfd3579f394",
+      "check_name": "PermitAttributes",
+      "message": "Potentially dangerous key allowed for mass assignment",
+      "file": "app/controllers/api/v1/crypto/deliveries_controller.rb",
+      "line": 23,
+      "link": "https://brakemanscanner.org/docs/warning_types/mass_assignment/",
+      "code": "params.require(:device).permit(:account_id, :device_id, :type, :body, :hmac)",
+      "render_path": null,
+      "location": {
+        "type": "method",
+        "class": "Api::V1::Crypto::DeliveriesController",
+        "method": "resource_params"
+      },
+      "user_input": ":account_id",
+      "confidence": "High",
       "note": ""
     },
     {
@@ -204,10 +209,22 @@
       "check_name": "Render",
       "message": "Render path contains parameter value",
       "file": "app/views/admin/accounts/index.html.haml",
-      "line": 47,
+      "line": 54,
       "link": "https://brakemanscanner.org/docs/warning_types/dynamic_render_path/",
       "code": "render(action => filtered_accounts.page(params[:page]), {})",
-      "render_path": [{"type":"controller","class":"Admin::AccountsController","method":"index","line":12,"file":"app/controllers/admin/accounts_controller.rb","rendered":{"name":"admin/accounts/index","file":"/home/eugr/Projects/mastodon/app/views/admin/accounts/index.html.haml"}}],
+      "render_path": [
+        {
+          "type": "controller",
+          "class": "Admin::AccountsController",
+          "method": "index",
+          "line": 12,
+          "file": "app/controllers/admin/accounts_controller.rb",
+          "rendered": {
+            "name": "admin/accounts/index",
+            "file": "app/views/admin/accounts/index.html.haml"
+          }
+        }
+      ],
       "location": {
         "type": "template",
         "template": "admin/accounts/index"
@@ -219,40 +236,40 @@
     {
       "warning_type": "Redirect",
       "warning_code": 18,
-      "fingerprint": "ba699ddcc6552c422c4ecd50d2cd217f616a2446659e185a50b05a0f2dad8d33",
+      "fingerprint": "ba568ac09683f98740f663f3d850c31785900215992e8c090497d359a2563d50",
       "check_name": "Redirect",
       "message": "Possible unprotected redirect",
-      "file": "app/controllers/media_controller.rb",
-      "line": 14,
+      "file": "app/controllers/remote_follow_controller.rb",
+      "line": 21,
       "link": "https://brakemanscanner.org/docs/warning_types/redirect/",
-      "code": "redirect_to(MediaAttachment.attached.find_by!(:shortcode => ((params[:id] or params[:medium_id]))).file.url(:original))",
+      "code": "redirect_to(RemoteFollow.new(resource_params).subscribe_address_for(@account))",
       "render_path": null,
       "location": {
         "type": "method",
-        "class": "MediaController",
-        "method": "show"
+        "class": "RemoteFollowController",
+        "method": "create"
       },
-      "user_input": "MediaAttachment.attached.find_by!(:shortcode => ((params[:id] or params[:medium_id]))).file.url(:original)",
+      "user_input": "RemoteFollow.new(resource_params).subscribe_address_for(@account)",
       "confidence": "High",
       "note": ""
     },
     {
       "warning_type": "Redirect",
       "warning_code": 18,
-      "fingerprint": "bb7e94e60af41decb811bb32171f1b27e9bf3f4d01e9e511127362e22510eb11",
+      "fingerprint": "ba699ddcc6552c422c4ecd50d2cd217f616a2446659e185a50b05a0f2dad8d33",
       "check_name": "Redirect",
       "message": "Possible unprotected redirect",
-      "file": "app/controllers/remote_follow_controller.rb",
-      "line": 19,
+      "file": "app/controllers/media_controller.rb",
+      "line": 20,
       "link": "https://brakemanscanner.org/docs/warning_types/redirect/",
-      "code": "redirect_to(RemoteFollow.new(resource_params).subscribe_address_for(Account.find_local!(params[:account_username])))",
+      "code": "redirect_to(MediaAttachment.attached.find_by!(:shortcode => ((params[:id] or params[:medium_id]))).file.url(:original))",
       "render_path": null,
       "location": {
         "type": "method",
-        "class": "RemoteFollowController",
-        "method": "create"
+        "class": "MediaController",
+        "method": "show"
       },
-      "user_input": "RemoteFollow.new(resource_params).subscribe_address_for(Account.find_local!(params[:account_username]))",
+      "user_input": "MediaAttachment.attached.find_by!(:shortcode => ((params[:id] or params[:medium_id]))).file.url(:original)",
       "confidence": "High",
       "note": ""
     },
@@ -275,27 +292,8 @@
       "user_input": ":account_id",
       "confidence": "High",
       "note": ""
-    },
-    {
-      "warning_type": "Dynamic Render Path",
-      "warning_code": 15,
-      "fingerprint": "fbd0fc59adb5c6d44b60e02debb31d3af11719f534c9881e21435bbff87404d6",
-      "check_name": "Render",
-      "message": "Render path contains parameter value",
-      "file": "app/views/stream_entries/show.html.haml",
-      "line": 23,
-      "link": "https://brakemanscanner.org/docs/warning_types/dynamic_render_path/",
-      "code": "render(partial => \"stream_entries/#{Account.find_local!(params[:account_username]).statuses.find(params[:id]).stream_entry.activity_type.downcase}\", { :locals => ({ Account.find_local!(params[:account_username]).statuses.find(params[:id]).stream_entry.activity_type.downcase.to_sym => Account.find_local!(params[:account_username]).statuses.find(params[:id]).stream_entry.activity, :include_threads => true }) })",
-      "render_path": [{"type":"controller","class":"StatusesController","method":"show","line":34,"file":"app/controllers/statuses_controller.rb","rendered":{"name":"stream_entries/show","file":"/home/eugr/Projects/mastodon/app/views/stream_entries/show.html.haml"}}],
-      "location": {
-        "type": "template",
-        "template": "stream_entries/show"
-      },
-      "user_input": "params[:id]",
-      "confidence": "Weak",
-      "note": ""
     }
   ],
-  "updated": "2019-02-21 02:30:29 +0100",
-  "brakeman_version": "4.4.0"
+  "updated": "2020-06-01 18:18:02 +0200",
+  "brakeman_version": "4.8.0"
 }
diff --git a/config/initializers/doorkeeper.rb b/config/initializers/doorkeeper.rb
index e03380cec..63cff7c59 100644
--- a/config/initializers/doorkeeper.rb
+++ b/config/initializers/doorkeeper.rb
@@ -95,7 +95,8 @@ Doorkeeper.configure do
                   :'admin:read:reports',
                   :'admin:write',
                   :'admin:write:accounts',
-                  :'admin:write:reports'
+                  :'admin:write:reports',
+                  :crypto
 
   # Change the way client credentials are retrieved from the request object.
   # By default it retrieves first from the `HTTP_AUTHORIZATION` header, then
diff --git a/config/initializers/inflections.rb b/config/initializers/inflections.rb
index 0667a542c..ebb7541eb 100644
--- a/config/initializers/inflections.rb
+++ b/config/initializers/inflections.rb
@@ -19,6 +19,7 @@ ActiveSupport::Inflector.inflections(:en) do |inflect|
   inflect.acronym 'ActivityStreams'
   inflect.acronym 'JsonLd'
   inflect.acronym 'NodeInfo'
+  inflect.acronym 'Ed25519'
 
   inflect.singular 'data', 'data'
 end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 116db4498..5943dd4f6 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -721,6 +721,10 @@ en:
     hint_html: "<strong>Tip:</strong> We won't ask you for your password again for the next hour."
     invalid_password: Invalid password
     prompt: Confirm password to continue
+  crypto:
+    errors:
+      invalid_key: is not a valid Ed25519 or Curve25519 key
+      invalid_signature: is not a valid Ed25519 signature
   date:
     formats:
       default: "%b %d, %Y"
diff --git a/config/routes.rb b/config/routes.rb
index 920a48fe7..31333999e 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -79,6 +79,7 @@ Rails.application.routes.draw do
 
     resource :outbox, only: [:show], module: :activitypub
     resource :inbox, only: [:create], module: :activitypub
+    resource :claim, only: [:create], module: :activitypub
     resources :collections, only: [:show], module: :activitypub
   end
 
@@ -339,6 +340,23 @@ Rails.application.routes.draw do
         end
       end
 
+      namespace :crypto do
+        resources :deliveries, only: :create
+
+        namespace :keys do
+          resource :upload, only: [:create]
+          resource :query,  only: [:create]
+          resource :claim,  only: [:create]
+          resource :count,  only: [:show]
+        end
+
+        resources :encrypted_messages, only: [:index] do
+          collection do
+            post :clear
+          end
+        end
+      end
+
       resources :conversations, only: [:index, :destroy] do
         member do
           post :read
diff --git a/db/migrate/20170129000348_create_devices.rb b/db/migrate/20170129000348_create_devices.rb
deleted file mode 100644
index bf8f5fc6e..000000000
--- a/db/migrate/20170129000348_create_devices.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-class CreateDevices < ActiveRecord::Migration[5.0]
-  def change
-    create_table :devices do |t|
-      t.integer :account_id, null: false
-      t.string :registration_id, null: false, default: ''
-
-      t.timestamps
-    end
-
-    add_index :devices, :registration_id
-    add_index :devices, :account_id
-  end
-end
diff --git a/db/migrate/20170205175257_remove_devices.rb b/db/migrate/20170205175257_remove_devices.rb
index e96ffed4d..9ef5c440e 100644
--- a/db/migrate/20170205175257_remove_devices.rb
+++ b/db/migrate/20170205175257_remove_devices.rb
@@ -1,5 +1,5 @@
 class RemoveDevices < ActiveRecord::Migration[5.0]
   def change
-    drop_table :devices
+    drop_table :devices if table_exists?(:devices)
   end
 end
diff --git a/db/migrate/20200516180352_create_devices.rb b/db/migrate/20200516180352_create_devices.rb
new file mode 100644
index 000000000..04a628a89
--- /dev/null
+++ b/db/migrate/20200516180352_create_devices.rb
@@ -0,0 +1,14 @@
+class CreateDevices < ActiveRecord::Migration[5.2]
+  def change
+    create_table :devices do |t|
+      t.references :access_token, foreign_key: { to_table: :oauth_access_tokens, on_delete: :cascade, index: :unique }
+      t.references :account, foreign_key: { on_delete: :cascade }
+      t.string :device_id, default: '', null: false
+      t.string :name, default: '', null: false
+      t.text :fingerprint_key, default: '', null: false
+      t.text :identity_key, default: '', null: false
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/migrate/20200516183822_create_one_time_keys.rb b/db/migrate/20200516183822_create_one_time_keys.rb
new file mode 100644
index 000000000..642b9e632
--- /dev/null
+++ b/db/migrate/20200516183822_create_one_time_keys.rb
@@ -0,0 +1,12 @@
+class CreateOneTimeKeys < ActiveRecord::Migration[5.2]
+  def change
+    create_table :one_time_keys do |t|
+      t.references :device, foreign_key: { on_delete: :cascade }
+      t.string :key_id, default: '', null: false, index: :unique
+      t.text :key, default: '', null: false
+      t.text :signature, default: '', null: false
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/migrate/20200518083523_create_encrypted_messages.rb b/db/migrate/20200518083523_create_encrypted_messages.rb
new file mode 100644
index 000000000..486726303
--- /dev/null
+++ b/db/migrate/20200518083523_create_encrypted_messages.rb
@@ -0,0 +1,15 @@
+class CreateEncryptedMessages < ActiveRecord::Migration[5.2]
+  def change
+    create_table :encrypted_messages do |t|
+      t.references :device, foreign_key: { on_delete: :cascade }
+      t.references :from_account, foreign_key: { to_table: :accounts, on_delete: :cascade }
+      t.string :from_device_id, default: '', null: false
+      t.integer :type, default: 0, null: false
+      t.text :body, default: '', null: false
+      t.text :digest, default: '', null: false
+      t.text :message_franking, default: '', null: false
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/migrate/20200521180606_encrypted_message_ids_to_timestamp_ids.rb b/db/migrate/20200521180606_encrypted_message_ids_to_timestamp_ids.rb
new file mode 100644
index 000000000..24d43a0bf
--- /dev/null
+++ b/db/migrate/20200521180606_encrypted_message_ids_to_timestamp_ids.rb
@@ -0,0 +1,13 @@
+class EncryptedMessageIdsToTimestampIds < ActiveRecord::Migration[5.2]
+  def up
+    safety_assured do
+      execute("ALTER TABLE encrypted_messages ALTER COLUMN id SET DEFAULT timestamp_id('encrypted_messages')")
+    end
+  end
+
+  def down
+    execute("LOCK encrypted_messages")
+    execute("SELECT setval('encrypted_messages_id_seq', (SELECT MAX(id) FROM encrypted_messages))")
+    execute("ALTER TABLE encrypted_messages ALTER COLUMN id SET DEFAULT nextval('encrypted_messages_id_seq')")
+  end
+end
diff --git a/db/migrate/20200529214050_add_devices_url_to_accounts.rb b/db/migrate/20200529214050_add_devices_url_to_accounts.rb
new file mode 100644
index 000000000..564877e5d
--- /dev/null
+++ b/db/migrate/20200529214050_add_devices_url_to_accounts.rb
@@ -0,0 +1,5 @@
+class AddDevicesUrlToAccounts < ActiveRecord::Migration[5.2]
+  def change
+    add_column :accounts, :devices_url, :string
+  end
+end
diff --git a/db/migrate/20200601222558_create_system_keys.rb b/db/migrate/20200601222558_create_system_keys.rb
new file mode 100644
index 000000000..fd9d221aa
--- /dev/null
+++ b/db/migrate/20200601222558_create_system_keys.rb
@@ -0,0 +1,9 @@
+class CreateSystemKeys < ActiveRecord::Migration[5.2]
+  def change
+    create_table :system_keys do |t|
+      t.binary :key
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 31f0c96bc..e220e13fe 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.define(version: 2020_05_10_110808) do
+ActiveRecord::Schema.define(version: 2020_06_01_222558) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -174,6 +174,7 @@ ActiveRecord::Schema.define(version: 2020_05_10_110808) do
     t.boolean "hide_collections"
     t.integer "avatar_storage_schema_version"
     t.integer "header_storage_schema_version"
+    t.string "devices_url"
     t.index "(((setweight(to_tsvector('simple'::regconfig, (display_name)::text), 'A'::\"char\") || setweight(to_tsvector('simple'::regconfig, (username)::text), 'B'::\"char\")) || setweight(to_tsvector('simple'::regconfig, (COALESCE(domain, ''::character varying))::text), 'C'::\"char\")))", name: "search_index", using: :gin
     t.index "lower((username)::text), lower((domain)::text)", name: "index_accounts_on_username_and_domain_lower", unique: true
     t.index ["moved_to_account_id"], name: "index_accounts_on_moved_to_account_id"
@@ -317,6 +318,19 @@ ActiveRecord::Schema.define(version: 2020_05_10_110808) do
     t.index ["account_id"], name: "index_custom_filters_on_account_id"
   end
 
+  create_table "devices", force: :cascade do |t|
+    t.bigint "access_token_id"
+    t.bigint "account_id"
+    t.string "device_id", default: "", null: false
+    t.string "name", default: "", null: false
+    t.text "fingerprint_key", default: "", null: false
+    t.text "identity_key", default: "", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["access_token_id"], name: "index_devices_on_access_token_id"
+    t.index ["account_id"], name: "index_devices_on_account_id"
+  end
+
   create_table "domain_allows", force: :cascade do |t|
     t.string "domain", default: "", null: false
     t.datetime "created_at", null: false
@@ -344,6 +358,20 @@ ActiveRecord::Schema.define(version: 2020_05_10_110808) do
     t.index ["domain"], name: "index_email_domain_blocks_on_domain", unique: true
   end
 
+  create_table "encrypted_messages", id: :bigint, default: -> { "timestamp_id('encrypted_messages'::text)" }, force: :cascade do |t|
+    t.bigint "device_id"
+    t.bigint "from_account_id"
+    t.string "from_device_id", default: "", null: false
+    t.integer "type", default: 0, null: false
+    t.text "body", default: "", null: false
+    t.text "digest", default: "", null: false
+    t.text "message_franking", default: "", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["device_id"], name: "index_encrypted_messages_on_device_id"
+    t.index ["from_account_id"], name: "index_encrypted_messages_on_from_account_id"
+  end
+
   create_table "favourites", force: :cascade do |t|
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
@@ -551,6 +579,17 @@ ActiveRecord::Schema.define(version: 2020_05_10_110808) do
     t.index ["uid"], name: "index_oauth_applications_on_uid", unique: true
   end
 
+  create_table "one_time_keys", force: :cascade do |t|
+    t.bigint "device_id"
+    t.string "key_id", default: "", null: false
+    t.text "key", default: "", null: false
+    t.text "signature", default: "", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["device_id"], name: "index_one_time_keys_on_device_id"
+    t.index ["key_id"], name: "index_one_time_keys_on_key_id"
+  end
+
   create_table "pghero_space_stats", force: :cascade do |t|
     t.text "database"
     t.text "schema"
@@ -749,6 +788,12 @@ ActiveRecord::Schema.define(version: 2020_05_10_110808) do
     t.index ["tag_id", "status_id"], name: "index_statuses_tags_on_tag_id_and_status_id", unique: true
   end
 
+  create_table "system_keys", force: :cascade do |t|
+    t.binary "key"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
   create_table "tags", force: :cascade do |t|
     t.string "name", default: "", null: false
     t.datetime "created_at", null: false
@@ -883,7 +928,11 @@ ActiveRecord::Schema.define(version: 2020_05_10_110808) do
   add_foreign_key "conversation_mutes", "accounts", name: "fk_225b4212bb", on_delete: :cascade
   add_foreign_key "conversation_mutes", "conversations", on_delete: :cascade
   add_foreign_key "custom_filters", "accounts", on_delete: :cascade
+  add_foreign_key "devices", "accounts", on_delete: :cascade
+  add_foreign_key "devices", "oauth_access_tokens", column: "access_token_id", on_delete: :cascade
   add_foreign_key "email_domain_blocks", "email_domain_blocks", column: "parent_id", on_delete: :cascade
+  add_foreign_key "encrypted_messages", "accounts", column: "from_account_id", on_delete: :cascade
+  add_foreign_key "encrypted_messages", "devices", on_delete: :cascade
   add_foreign_key "favourites", "accounts", name: "fk_5eb6c2b873", on_delete: :cascade
   add_foreign_key "favourites", "statuses", name: "fk_b0e856845e", on_delete: :cascade
   add_foreign_key "featured_tags", "accounts", on_delete: :cascade
@@ -914,6 +963,7 @@ ActiveRecord::Schema.define(version: 2020_05_10_110808) do
   add_foreign_key "oauth_access_tokens", "oauth_applications", column: "application_id", name: "fk_f5fc4c1ee3", on_delete: :cascade
   add_foreign_key "oauth_access_tokens", "users", column: "resource_owner_id", name: "fk_e84df68546", on_delete: :cascade
   add_foreign_key "oauth_applications", "users", column: "owner_id", name: "fk_b0988c7c0a", on_delete: :cascade
+  add_foreign_key "one_time_keys", "devices", on_delete: :cascade
   add_foreign_key "poll_votes", "accounts", on_delete: :cascade
   add_foreign_key "poll_votes", "polls", on_delete: :cascade
   add_foreign_key "polls", "accounts", on_delete: :cascade
diff --git a/spec/fabricators/device_fabricator.rb b/spec/fabricators/device_fabricator.rb
new file mode 100644
index 000000000..b15d8248f
--- /dev/null
+++ b/spec/fabricators/device_fabricator.rb
@@ -0,0 +1,8 @@
+Fabricator(:device) do
+  access_token
+  account
+  device_id        { Faker::Number.number(digits: 5) }
+  name             { Faker::App.name }
+  fingerprint_key  { Base64.strict_encode64(Ed25519::SigningKey.generate.verify_key.to_bytes) }
+  identity_key     { Base64.strict_encode64(Ed25519::SigningKey.generate.verify_key.to_bytes) }
+end
diff --git a/spec/fabricators/encrypted_message_fabricator.rb b/spec/fabricators/encrypted_message_fabricator.rb
new file mode 100644
index 000000000..e65f66302
--- /dev/null
+++ b/spec/fabricators/encrypted_message_fabricator.rb
@@ -0,0 +1,8 @@
+Fabricator(:encrypted_message) do
+  device
+  from_account
+  from_device_id   { Faker::Number.number(digits: 5) }
+  type             0
+  body             ""
+  message_franking ""
+end
diff --git a/spec/fabricators/one_time_key_fabricator.rb b/spec/fabricators/one_time_key_fabricator.rb
new file mode 100644
index 000000000..8794baeb5
--- /dev/null
+++ b/spec/fabricators/one_time_key_fabricator.rb
@@ -0,0 +1,11 @@
+Fabricator(:one_time_key) do
+  device
+  key_id { Faker::Alphanumeric.alphanumeric(number: 10) }
+  key    { Base64.strict_encode64(Ed25519::SigningKey.generate.verify_key.to_bytes) }
+
+  signature do |attrs|
+    signing_key = Ed25519::SigningKey.generate
+    attrs[:device].update(fingerprint_key: Base64.strict_encode64(signing_key.verify_key.to_bytes))
+    Base64.strict_encode64(signing_key.sign(attrs[:key]))
+  end
+end
diff --git a/spec/fabricators/system_key_fabricator.rb b/spec/fabricators/system_key_fabricator.rb
new file mode 100644
index 000000000..f808495e0
--- /dev/null
+++ b/spec/fabricators/system_key_fabricator.rb
@@ -0,0 +1,3 @@
+Fabricator(:system_key) do
+
+end
diff --git a/spec/lib/activitypub/activity/create_spec.rb b/spec/lib/activitypub/activity/create_spec.rb
index 5220deabb..2ac4acc12 100644
--- a/spec/lib/activitypub/activity/create_spec.rb
+++ b/spec/lib/activitypub/activity/create_spec.rb
@@ -579,6 +579,62 @@ RSpec.describe ActivityPub::Activity::Create do
       end
     end
 
+    context 'with an encrypted message' do
+      let(:recipient) { Fabricate(:account) }
+      let(:target_device) { Fabricate(:device, account: recipient) }
+
+      subject { described_class.new(json, sender, delivery: true, delivered_to_account_id: recipient.id) }
+
+      let(:object_json) do
+        {
+          id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
+          type: 'EncryptedMessage',
+          attributedTo: {
+            type: 'Device',
+            deviceId: '1234',
+          },
+          to: {
+            type: 'Device',
+            deviceId: target_device.device_id,
+          },
+          messageType: 1,
+          cipherText: 'Foo',
+          messageFranking: 'Baz678',
+          digest: {
+            digestAlgorithm: 'Bar456',
+            digestValue: 'Foo123',
+          },
+        }
+      end
+
+      before do
+        subject.perform
+      end
+
+      it 'creates an encrypted message' do
+        encrypted_message = target_device.encrypted_messages.reload.first
+
+        expect(encrypted_message).to_not be_nil
+        expect(encrypted_message.from_device_id).to eq '1234'
+        expect(encrypted_message.from_account).to eq sender
+        expect(encrypted_message.type).to eq 1
+        expect(encrypted_message.body).to eq 'Foo'
+        expect(encrypted_message.digest).to eq 'Foo123'
+      end
+
+      it 'creates a message franking' do
+        encrypted_message = target_device.encrypted_messages.reload.first
+        message_franking  = encrypted_message.message_franking
+
+        crypt = ActiveSupport::MessageEncryptor.new(SystemKey.current_key, serializer: Oj)
+        json  = crypt.decrypt_and_verify(message_franking)
+
+        expect(json['source_account_id']).to eq sender.id
+        expect(json['target_account_id']).to eq recipient.id
+        expect(json['original_franking']).to eq 'Baz678'
+      end
+    end
+
     context 'when sender is followed by local users' do
       subject { described_class.new(json, sender, delivery: true) }
 
diff --git a/spec/models/device_spec.rb b/spec/models/device_spec.rb
new file mode 100644
index 000000000..f56fbf978
--- /dev/null
+++ b/spec/models/device_spec.rb
@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe Device, type: :model do
+
+end
diff --git a/spec/models/encrypted_message_spec.rb b/spec/models/encrypted_message_spec.rb
new file mode 100644
index 000000000..1238d57b6
--- /dev/null
+++ b/spec/models/encrypted_message_spec.rb
@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe EncryptedMessage, type: :model do
+
+end
diff --git a/spec/models/one_time_key_spec.rb b/spec/models/one_time_key_spec.rb
new file mode 100644
index 000000000..34598334c
--- /dev/null
+++ b/spec/models/one_time_key_spec.rb
@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe OneTimeKey, type: :model do
+
+end
diff --git a/spec/models/system_key_spec.rb b/spec/models/system_key_spec.rb
new file mode 100644
index 000000000..a138bc131
--- /dev/null
+++ b/spec/models/system_key_spec.rb
@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe SystemKey, type: :model do
+
+end
diff --git a/streaming/index.js b/streaming/index.js
index 500d577ce..d7b1df81f 100644
--- a/streaming/index.js
+++ b/streaming/index.js
@@ -144,13 +144,21 @@ const startWorker = (workerId) => {
     callbacks.forEach(callback => callback(message));
   });
 
-  const subscriptionHeartbeat = (channel) => {
-    const interval = 6*60;
+  const subscriptionHeartbeat = channels => {
+    if (!Array.isArray(channels)) {
+      channels = [channels];
+    }
+
+    const interval = 6 * 60;
+
     const tellSubscribed = () => {
-      redisClient.set(`${redisPrefix}subscribed:${channel}`, '1', 'EX', interval*3);
+      channels.forEach(channel => redisClient.set(`${redisPrefix}subscribed:${channel}`, '1', 'EX', interval * 3));
     };
+
     tellSubscribed();
-    const heartbeat = setInterval(tellSubscribed, interval*1000);
+
+    const heartbeat = setInterval(tellSubscribed, interval * 1000);
+
     return () => {
       clearInterval(heartbeat);
     };
@@ -203,7 +211,7 @@ const startWorker = (workerId) => {
         return;
       }
 
-      client.query('SELECT oauth_access_tokens.resource_owner_id, users.account_id, users.chosen_languages, oauth_access_tokens.scopes FROM oauth_access_tokens INNER JOIN users ON oauth_access_tokens.resource_owner_id = users.id WHERE oauth_access_tokens.token = $1 AND oauth_access_tokens.revoked_at IS NULL LIMIT 1', [token], (err, result) => {
+      client.query('SELECT oauth_access_tokens.resource_owner_id, users.account_id, users.chosen_languages, oauth_access_tokens.scopes, devices.device_id FROM oauth_access_tokens INNER JOIN users ON oauth_access_tokens.resource_owner_id = users.id LEFT OUTER JOIN devices ON oauth_access_tokens.id = devices.access_token_id WHERE oauth_access_tokens.token = $1 AND oauth_access_tokens.revoked_at IS NULL LIMIT 1', [token], (err, result) => {
         done();
 
         if (err) {
@@ -232,6 +240,7 @@ const startWorker = (workerId) => {
         req.accountId = result.rows[0].account_id;
         req.chosenLanguages = result.rows[0].chosen_languages;
         req.allowNotifications = scopes.some(scope => ['read', 'read:notifications'].includes(scope));
+        req.deviceId = result.rows[0].device_id;
 
         next();
       });
@@ -353,11 +362,15 @@ const startWorker = (workerId) => {
     });
   };
 
-  const streamFrom = (id, req, output, attachCloseHandler, needsFiltering = false, notificationOnly = false) => {
-    const accountId = req.accountId || req.remoteAddress;
-
+  const streamFrom = (ids, req, output, attachCloseHandler, needsFiltering = false, notificationOnly = false) => {
+    const accountId  = req.accountId || req.remoteAddress;
     const streamType = notificationOnly ? ' (notification)' : '';
-    log.verbose(req.requestId, `Starting stream from ${id} for ${accountId}${streamType}`);
+
+    if (!Array.isArray(ids)) {
+      ids = [ids];
+    }
+
+    log.verbose(req.requestId, `Starting stream from ${ids.join(', ')} for ${accountId}${streamType}`);
 
     const listener = message => {
       const { event, payload, queued_at } = JSON.parse(message);
@@ -430,8 +443,11 @@ const startWorker = (workerId) => {
       });
     };
 
-    subscribe(`${redisPrefix}${id}`, listener);
-    attachCloseHandler(`${redisPrefix}${id}`, listener);
+    ids.forEach(id => {
+      subscribe(`${redisPrefix}${id}`, listener);
+    });
+
+    attachCloseHandler(ids.map(id => `${redisPrefix}${id}`), listener);
   };
 
   // Setup stream output to HTTP
@@ -458,9 +474,16 @@ const startWorker = (workerId) => {
   };
 
   // Setup stream end for HTTP
-  const streamHttpEnd = (req, closeHandler = false) => (id, listener) => {
+  const streamHttpEnd = (req, closeHandler = false) => (ids, listener) => {
+    if (!Array.isArray(ids)) {
+      ids = [ids];
+    }
+
     req.on('close', () => {
-      unsubscribe(id, listener);
+      ids.forEach(id => {
+        unsubscribe(id, listener);
+      });
+
       if (closeHandler) {
         closeHandler();
       }
@@ -516,8 +539,13 @@ const startWorker = (workerId) => {
   app.use(errorMiddleware);
 
   app.get('/api/v1/streaming/user', (req, res) => {
-    const channel = `timeline:${req.accountId}`;
-    streamFrom(channel, req, streamToHttp(req, res), streamHttpEnd(req, subscriptionHeartbeat(channel)));
+    const channels = [`timeline:${req.accountId}`];
+
+    if (req.deviceId) {
+      channels.push(`timeline:${req.accountId}:${req.deviceId}`);
+    }
+
+    streamFrom(channels, req, streamToHttp(req, res), streamHttpEnd(req, subscriptionHeartbeat(channels)));
   });
 
   app.get('/api/v1/streaming/user/notification', (req, res) => {
@@ -597,7 +625,12 @@ const startWorker = (workerId) => {
 
     switch(location.query.stream) {
     case 'user':
-      channel = `timeline:${req.accountId}`;
+      channel = [`timeline:${req.accountId}`];
+
+      if (req.deviceId) {
+        channel.push(`timeline:${req.accountId}:${req.deviceId}`);
+      }
+
       streamFrom(channel, req, streamToWs(req, ws), streamWsEnd(req, ws, subscriptionHeartbeat(channel)));
       break;
     case 'user:notification':