diff --git a/app/sql.js b/app/sql.js
index 7e958462e4..9dfb2bcb8d 100644
--- a/app/sql.js
+++ b/app/sql.js
@@ -94,7 +94,6 @@ module.exports = {
   getOutgoingWithoutExpiresAt,
   getNextExpiringMessage,
   getMessagesByConversation,
-  getNextTapToViewMessageToExpire,
   getNextTapToViewMessageToAgeOut,
   getTapToViewMessagesNeedingErase,
 
@@ -952,6 +951,68 @@ async function updateToSchemaVersion16(currentVersion, instance) {
   }
 }
 
+async function updateToSchemaVersion17(currentVersion, instance) {
+  if (currentVersion >= 17) {
+    return;
+  }
+
+  console.log('updateToSchemaVersion17: starting...');
+  await instance.run('BEGIN TRANSACTION;');
+
+  try {
+    await instance.run(
+      `ALTER TABLE messages
+      ADD COLUMN isViewOnce INTEGER;`
+    );
+
+    await instance.run('DROP INDEX messages_message_timer;');
+
+    await instance.run(`CREATE INDEX messages_view_once ON messages (
+      isErased
+    ) WHERE isViewOnce = 1;`);
+
+    // Updating full-text triggers to avoid anything with isViewOnce = 1
+
+    await instance.run('DROP TRIGGER messages_on_insert;');
+    await instance.run('DROP TRIGGER messages_on_update;');
+
+    await instance.run(`
+      CREATE TRIGGER messages_on_insert AFTER INSERT ON messages
+      WHEN new.isViewOnce != 1
+      BEGIN
+        INSERT INTO messages_fts (
+          id,
+          body
+        ) VALUES (
+          new.id,
+          new.body
+        );
+      END;
+    `);
+    await instance.run(`
+      CREATE TRIGGER messages_on_update AFTER UPDATE ON messages
+      WHEN new.isViewOnce != 1
+      BEGIN
+        DELETE FROM messages_fts WHERE id = old.id;
+        INSERT INTO messages_fts(
+          id,
+          body
+        ) VALUES (
+          new.id,
+          new.body
+        );
+      END;
+    `);
+
+    await instance.run('PRAGMA schema_version = 17;');
+    await instance.run('COMMIT TRANSACTION;');
+    console.log('updateToSchemaVersion17: success!');
+  } catch (error) {
+    await instance.run('ROLLBACK;');
+    throw error;
+  }
+}
+
 const SCHEMA_VERSIONS = [
   updateToSchemaVersion1,
   updateToSchemaVersion2,
@@ -969,6 +1030,7 @@ const SCHEMA_VERSIONS = [
   updateToSchemaVersion14,
   updateToSchemaVersion15,
   updateToSchemaVersion16,
+  updateToSchemaVersion17,
 ];
 
 async function updateSchema(instance) {
@@ -1566,9 +1628,7 @@ async function saveMessage(data, { forceSave } = {}) {
     hasVisualMediaAttachments,
     id,
     isErased,
-    messageTimer,
-    messageTimerStart,
-    messageTimerExpiresAt,
+    isViewOnce,
     // eslint-disable-next-line camelcase
     received_at,
     schemaVersion,
@@ -1595,9 +1655,7 @@ async function saveMessage(data, { forceSave } = {}) {
     $hasFileAttachments: hasFileAttachments,
     $hasVisualMediaAttachments: hasVisualMediaAttachments,
     $isErased: isErased,
-    $messageTimer: messageTimer,
-    $messageTimerStart: messageTimerStart,
-    $messageTimerExpiresAt: messageTimerExpiresAt,
+    $isViewOnce: isViewOnce,
     $received_at: received_at,
     $schemaVersion: schemaVersion,
     $sent_at: sent_at,
@@ -1622,9 +1680,7 @@ async function saveMessage(data, { forceSave } = {}) {
         hasFileAttachments = $hasFileAttachments,
         hasVisualMediaAttachments = $hasVisualMediaAttachments,
         isErased = $isErased,
-        messageTimer = $messageTimer,
-        messageTimerStart = $messageTimerStart,
-        messageTimerExpiresAt = $messageTimerExpiresAt,
+        isViewOnce = $isViewOnce,
         received_at = $received_at,
         schemaVersion = $schemaVersion,
         sent_at = $sent_at,
@@ -1658,9 +1714,7 @@ async function saveMessage(data, { forceSave } = {}) {
     hasFileAttachments,
     hasVisualMediaAttachments,
     isErased,
-    messageTimer,
-    messageTimerStart,
-    messageTimerExpiresAt,
+    isViewOnce,
     received_at,
     schemaVersion,
     sent_at,
@@ -1681,9 +1735,7 @@ async function saveMessage(data, { forceSave } = {}) {
     $hasFileAttachments,
     $hasVisualMediaAttachments,
     $isErased,
-    $messageTimer,
-    $messageTimerStart,
-    $messageTimerExpiresAt,
+    $isViewOnce,
     $received_at,
     $schemaVersion,
     $sent_at,
@@ -1862,31 +1914,11 @@ async function getNextExpiringMessage() {
   return map(rows, row => jsonToObject(row.json));
 }
 
-async function getNextTapToViewMessageToExpire() {
-  // Note: we avoid 'IS NOT NULL' here because it does seem to bypass our index
-  const rows = await db.all(`
-    SELECT json FROM messages
-    WHERE
-      messageTimer > 0
-      AND messageTimerExpiresAt > 0
-      AND (isErased IS NULL OR isErased != 1)
-    ORDER BY messageTimerExpiresAt ASC
-    LIMIT 1;
-  `);
-
-  if (!rows || rows.length < 1) {
-    return null;
-  }
-
-  return jsonToObject(rows[0].json);
-}
-
 async function getNextTapToViewMessageToAgeOut() {
-  // Note: we avoid 'IS NOT NULL' here because it does seem to bypass our index
   const rows = await db.all(`
     SELECT json FROM messages
     WHERE
-      messageTimer > 0
+      isViewOnce = 1
       AND (isErased IS NULL OR isErased != 1)
     ORDER BY received_at ASC
     LIMIT 1;
@@ -1903,18 +1935,12 @@ async function getTapToViewMessagesNeedingErase() {
   const THIRTY_DAYS_AGO = Date.now() - 30 * 24 * 60 * 60 * 1000;
   const NOW = Date.now();
 
-  // Note: we avoid 'IS NOT NULL' here because it does seem to bypass our index
   const rows = await db.all(
     `SELECT json FROM messages
     WHERE
-      messageTimer > 0
+      isViewOnce = 1
       AND (isErased IS NULL OR isErased != 1)
-      AND (
-        (messageTimerExpiresAt > 0
-        AND messageTimerExpiresAt <= $NOW)
-        OR
-        received_at <= $THIRTY_DAYS_AGO
-      )
+      AND received_at <= $THIRTY_DAYS_AGO
     ORDER BY received_at ASC;`,
     {
       $NOW: NOW,
diff --git a/js/background.js b/js/background.js
index 347a1dca90..e2fe47861b 100644
--- a/js/background.js
+++ b/js/background.js
@@ -1698,13 +1698,12 @@
   }
 
   async function onViewSync(ev) {
-    const { viewedAt, source, timestamp } = ev;
-    window.log.info(`view sync ${source} ${timestamp}, viewed at ${viewedAt}`);
+    const { source, timestamp } = ev;
+    window.log.info(`view sync ${source} ${timestamp}`);
 
     const sync = Whisper.ViewSyncs.add({
       source,
       timestamp,
-      viewedAt,
     });
 
     sync.on('remove', ev.confirm);
diff --git a/js/expiring_tap_to_view_messages.js b/js/expiring_tap_to_view_messages.js
index f8364781c0..16522b51e0 100644
--- a/js/expiring_tap_to_view_messages.js
+++ b/js/expiring_tap_to_view_messages.js
@@ -52,22 +52,12 @@
     const toAgeOut = await window.Signal.Data.getNextTapToViewMessageToAgeOut({
       Message: Whisper.Message,
     });
-    const toExpire = await window.Signal.Data.getNextTapToViewMessageToExpire({
-      Message: Whisper.Message,
-    });
 
-    if (!toAgeOut && !toExpire) {
+    if (!toAgeOut) {
       return;
     }
 
-    const ageOutAt = toAgeOut
-      ? toAgeOut.get('received_at') + THIRTY_DAYS
-      : Number.MAX_VALUE;
-    const expireAt = toExpire
-      ? toExpire.get('messageTimerExpiresAt')
-      : Number.MAX_VALUE;
-
-    const nextCheck = Math.min(ageOutAt, expireAt);
+    const nextCheck = toAgeOut.get('received_at') + THIRTY_DAYS;
 
     Whisper.TapToViewMessagesListener.nextCheck = nextCheck;
     window.log.info(
diff --git a/js/models/messages.js b/js/models/messages.js
index 32f3c84b82..404fd2e4ab 100644
--- a/js/models/messages.js
+++ b/js/models/messages.js
@@ -495,8 +495,7 @@
         expirationTimestamp,
 
         isTapToView,
-        isTapToViewExpired:
-          isTapToView && (this.get('isErased') || this.isTapToViewExpired()),
+        isTapToViewExpired: isTapToView && this.get('isErased'),
         isTapToViewError:
           isTapToView && this.isIncoming() && this.get('isTapToViewInvalid'),
 
@@ -870,7 +869,7 @@
       }
     },
     isTapToView() {
-      return Boolean(this.get('messageTimer'));
+      return Boolean(this.get('isViewOnce') || this.get('messageTimer'));
     },
     isValidTapToView() {
       const body = this.get('body');
@@ -908,66 +907,27 @@
 
       return true;
     },
-    isTapToViewExpired() {
-      const THIRTY_DAYS = 30 * 24 * 60 * 60 * 1000;
-      const now = Date.now();
-
-      const receivedAt = this.get('received_at');
-      if (now >= receivedAt + THIRTY_DAYS) {
-        return true;
-      }
-
-      const messageTimer = this.get('messageTimer');
-      const messageTimerStart = this.get('messageTimerStart');
-      if (!messageTimerStart) {
-        return false;
-      }
-
-      const expiresAt = messageTimerStart + messageTimer * 1000;
-      if (now >= expiresAt) {
-        return true;
-      }
-
-      return false;
-    },
-    async startTapToViewTimer(viewedAt, options) {
+    async markViewed(options) {
       const { fromSync } = options || {};
 
+      if (!this.isValidTapToView()) {
+        window.log.warn(
+          `markViewed: Message ${this.idForLogging()} is not a valid tap to view message!`
+        );
+        return;
+      }
+      if (this.isErased()) {
+        window.log.warn(
+          `markViewed: Message ${this.idForLogging()} is already erased!`
+        );
+        return;
+      }
+
       if (this.get('unread')) {
         await this.markRead();
       }
 
-      const messageTimer = this.get('messageTimer');
-      if (!messageTimer) {
-        window.log.warn(
-          `startTapToViewTimer: Message ${this.idForLogging()} has no messageTimer!`
-        );
-        return;
-      }
-
-      const existingTimerStart = this.get('messageTimerStart');
-      const messageTimerStart = Math.min(
-        Date.now(),
-        viewedAt || Date.now(),
-        existingTimerStart || Date.now()
-      );
-      const messageTimerExpiresAt = messageTimerStart + messageTimer * 1000;
-
-      // Because we're not using Backbone-integrated saves, we need to manually
-      //   clear the changed fields here so our hasChanged() check below is useful.
-      this.changed = {};
-      this.set({
-        messageTimerStart,
-        messageTimerExpiresAt,
-      });
-
-      if (!this.hasChanged()) {
-        return;
-      }
-
-      await window.Signal.Data.saveMessage(this.attributes, {
-        Message: Whisper.Message,
-      });
+      await this.eraseContents();
 
       if (!fromSync) {
         const sender = this.getSource();
@@ -979,14 +939,13 @@
         );
 
         await wrap(
-          textsecure.messaging.syncMessageTimerRead(
-            sender,
-            timestamp,
-            sendOptions
-          )
+          textsecure.messaging.syncViewOnceOpen(sender, timestamp, sendOptions)
         );
       }
     },
+    isErased() {
+      return Boolean(this.get('isErased'));
+    },
     async eraseContents() {
       if (this.get('isErased')) {
         return;
@@ -1940,7 +1899,7 @@
             hasAttachments: dataMessage.hasAttachments,
             hasFileAttachments: dataMessage.hasFileAttachments,
             hasVisualMediaAttachments: dataMessage.hasVisualMediaAttachments,
-            messageTimer: dataMessage.messageTimer,
+            isViewOnce: Boolean(dataMessage.isViewOnce),
             preview,
             requiredProtocolVersion:
               dataMessage.requiredProtocolVersion ||
diff --git a/js/modules/backup.js b/js/modules/backup.js
index edfe5af544..c9b659e091 100644
--- a/js/modules/backup.js
+++ b/js/modules/backup.js
@@ -715,7 +715,7 @@ async function exportConversation(conversation, options = {}) {
       count += 1;
 
       // skip message if it is disappearing, no matter the amount of time left
-      if (message.expireTimer || message.messageTimer) {
+      if (message.expireTimer || message.messageTimer || message.isViewOnce) {
         // eslint-disable-next-line no-continue
         continue;
       }
diff --git a/js/modules/data.js b/js/modules/data.js
index 1c63f73676..2d3dd93dc6 100644
--- a/js/modules/data.js
+++ b/js/modules/data.js
@@ -122,7 +122,6 @@ module.exports = {
   getOutgoingWithoutExpiresAt,
   getNextExpiringMessage,
   getMessagesByConversation,
-  getNextTapToViewMessageToExpire,
   getNextTapToViewMessageToAgeOut,
   getTapToViewMessagesNeedingErase,
 
@@ -842,14 +841,6 @@ async function getNextExpiringMessage({ MessageCollection }) {
   return new MessageCollection(messages);
 }
 
-async function getNextTapToViewMessageToExpire({ Message }) {
-  const message = await channels.getNextTapToViewMessageToExpire();
-  if (!message) {
-    return null;
-  }
-
-  return new Message(message);
-}
 async function getNextTapToViewMessageToAgeOut({ Message }) {
   const message = await channels.getNextTapToViewMessageToAgeOut();
   if (!message) {
diff --git a/js/modules/signal.js b/js/modules/signal.js
index 3aed32062e..fd0a618815 100644
--- a/js/modules/signal.js
+++ b/js/modules/signal.js
@@ -169,10 +169,14 @@ function initializeMigrations({
   const writeNewTempData = createWriterForNew(tempPath);
   const deleteTempFile = Attachments.createDeleter(tempPath);
   const readTempData = createReader(tempPath);
+  const copyIntoTempDirectory = Attachments.copyIntoAttachmentsDirectory(
+    tempPath
+  );
 
   return {
     attachmentsPath,
     copyIntoAttachmentsDirectory,
+    copyIntoTempDirectory,
     deleteAttachmentData: deleteOnDisk,
     deleteExternalMessageFiles: MessageType.deleteAllExternalFiles({
       deleteAttachmentData: Type.deleteData(deleteOnDisk),
@@ -182,6 +186,7 @@ function initializeMigrations({
     deleteTempFile,
     getAbsoluteAttachmentPath,
     getAbsoluteStickerPath,
+    getAbsoluteTempPath,
     getPlaceholderMigrations,
     getCurrentVersion,
     loadAttachmentData,
diff --git a/js/view_syncs.js b/js/view_syncs.js
index fa0fc2fe3f..5eea0d0717 100644
--- a/js/view_syncs.js
+++ b/js/view_syncs.js
@@ -51,9 +51,7 @@
         }
 
         const message = MessageController.register(found.id, found);
-
-        const viewedAt = sync.get('viewedAt');
-        await message.startTapToViewTimer(viewedAt, { fromSync: true });
+        await message.markViewed({ fromSync: true });
 
         this.remove(sync);
       } catch (error) {
diff --git a/js/views/conversation_view.js b/js/views/conversation_view.js
index 37a706ecde..2ef9992551 100644
--- a/js/views/conversation_view.js
+++ b/js/views/conversation_view.js
@@ -19,6 +19,9 @@
   const {
     upgradeMessageSchema,
     getAbsoluteAttachmentPath,
+    copyIntoTempDirectory,
+    getAbsoluteTempPath,
+    deleteTempFile,
   } = window.Signal.Migrations;
 
   Whisper.ExpiredToast = Whisper.ToastView.extend({
@@ -1324,17 +1327,33 @@
 
       if (!message.isTapToView()) {
         throw new Error(
-          `displayTapToViewMessage: Message ${message.idForLogging()} is not tap to view`
+          `displayTapToViewMessage: Message ${message.idForLogging()} is not a tap to view message`
         );
       }
 
-      if (message.isTapToViewExpired()) {
-        return;
+      if (message.isErased()) {
+        throw new Error(
+          `displayTapToViewMessage: Message ${message.idForLogging()} is already erased`
+        );
       }
 
-      await message.startTapToViewTimer();
+      const firstAttachment = message.get('attachments')[0];
+      if (!firstAttachment || !firstAttachment.path) {
+        throw new Error(
+          `displayTapToViewMessage: Message ${message.idForLogging()} had no first attachment with path`
+        );
+      }
 
-      const closeLightbox = () => {
+      const absolutePath = getAbsoluteAttachmentPath(firstAttachment.path);
+      const tempPath = await copyIntoTempDirectory(absolutePath);
+      const tempAttachment = {
+        ...firstAttachment,
+        path: tempPath,
+      };
+
+      await message.markViewed();
+
+      const closeLightbox = async () => {
         if (!this.lightboxView) {
           return;
         }
@@ -1345,6 +1364,8 @@
         this.stopListening(message);
         Signal.Backbone.Views.Lightbox.hide();
         lightboxView.remove();
+
+        await deleteTempFile(tempPath);
       };
       this.listenTo(message, 'expired', closeLightbox);
       this.listenTo(message, 'change', () => {
@@ -1354,14 +1375,11 @@
       });
 
       const getProps = () => {
-        const firstAttachment = message.get('attachments')[0];
-        const { path, contentType } = firstAttachment;
+        const { path, contentType } = tempAttachment;
 
         return {
-          objectURL: getAbsoluteAttachmentPath(path),
+          objectURL: getAbsoluteTempPath(path),
           contentType,
-          timerExpiresAt: message.get('messageTimerExpiresAt'),
-          timerDuration: message.get('messageTimer') * 1000,
         };
       };
       this.lightboxView = new Whisper.ReactWrapperView({
diff --git a/libtextsecure/message_receiver.js b/libtextsecure/message_receiver.js
index 6ab621d05f..f00c97e5fc 100644
--- a/libtextsecure/message_receiver.js
+++ b/libtextsecure/message_receiver.js
@@ -1090,11 +1090,8 @@ MessageReceiver.prototype.extend({
         envelope,
         syncMessage.stickerPackOperation
       );
-    } else if (syncMessage.messageTimerRead) {
-      return this.handleMessageTimerRead(
-        envelope,
-        syncMessage.messageTimerRead
-      );
+    } else if (syncMessage.viewOnceOpen) {
+      return this.handleViewOnceOpen(envelope, syncMessage.viewOnceOpen);
     }
     throw new Error('Got empty SyncMessage');
   },
@@ -1105,14 +1102,13 @@ MessageReceiver.prototype.extend({
     ev.configuration = configuration;
     return this.dispatchAndWait(ev);
   },
-  handleMessageTimerRead(envelope, sync) {
-    window.log.info('got message timer read sync message');
+  handleViewOnceOpen(envelope, sync) {
+    window.log.info('got view once open sync message');
 
     const ev = new Event('viewSync');
     ev.confirm = this.removeFromCache.bind(this, envelope);
     ev.source = sync.sender;
     ev.timestamp = sync.timestamp ? sync.timestamp.toNumber() : null;
-    ev.viewedAt = envelope.timestamp;
 
     return this.dispatchAndWait(ev);
   },
diff --git a/libtextsecure/sendmessage.js b/libtextsecure/sendmessage.js
index 761588d790..5716b7dede 100644
--- a/libtextsecure/sendmessage.js
+++ b/libtextsecure/sendmessage.js
@@ -745,7 +745,7 @@ MessageSender.prototype = {
     return Promise.resolve();
   },
 
-  async syncMessageTimerRead(sender, timestamp, options) {
+  async syncViewOnceOpen(sender, timestamp, options) {
     const myNumber = textsecure.storage.user.getNumber();
     const myDevice = textsecure.storage.user.getDeviceId();
     if (myDevice === 1 || myDevice === '1') {
@@ -754,10 +754,10 @@ MessageSender.prototype = {
 
     const syncMessage = this.createSyncMessage();
 
-    const messageTimerRead = new textsecure.protobuf.SyncMessage.MessageTimerRead();
-    messageTimerRead.sender = sender;
-    messageTimerRead.timestamp = timestamp;
-    syncMessage.messageTimerRead = messageTimerRead;
+    const viewOnceOpen = new textsecure.protobuf.SyncMessage.ViewOnceOpen();
+    viewOnceOpen.sender = sender;
+    viewOnceOpen.timestamp = timestamp;
+    syncMessage.viewOnceOpen = viewOnceOpen;
 
     const contentMessage = new textsecure.protobuf.Content();
     contentMessage.syncMessage = syncMessage;
@@ -1260,7 +1260,7 @@ textsecure.MessageSender = function MessageSenderWrapper(username, password) {
   this.getSticker = sender.getSticker.bind(sender);
   this.getStickerPackManifest = sender.getStickerPackManifest.bind(sender);
   this.sendStickerPackSync = sender.sendStickerPackSync.bind(sender);
-  this.syncMessageTimerRead = sender.syncMessageTimerRead.bind(sender);
+  this.syncViewOnceOpen = sender.syncViewOnceOpen.bind(sender);
 };
 
 textsecure.MessageSender.prototype = {
diff --git a/protos/SignalService.proto b/protos/SignalService.proto
index cd51db361a..582f2da4da 100644
--- a/protos/SignalService.proto
+++ b/protos/SignalService.proto
@@ -174,7 +174,8 @@ message DataMessage {
 
     INITIAL = 0;
     MESSAGE_TIMERS = 1;
-    CURRENT = 1;
+    VIEW_ONCE = 2;
+    CURRENT = 2;
   }
 
   optional string             body                    = 1;
@@ -189,7 +190,7 @@ message DataMessage {
   repeated Preview            preview                 = 10;
   optional Sticker            sticker                 = 11;
   optional uint32             requiredProtocolVersion = 12;
-  optional uint32             messageTimer            = 13;
+  optional bool               isViewOnce              = 14;
 }
 
 message NullMessage {
@@ -293,7 +294,7 @@ message SyncMessage {
     optional Type  type    = 3;
   }
 
-  message MessageTimerRead {
+  message ViewOnceOpen {
     optional string sender    = 1;
     optional uint64 timestamp = 2;
   }
@@ -308,7 +309,7 @@ message SyncMessage {
   optional Configuration        configuration        = 9;
   optional bytes                padding              = 8;
   repeated StickerPackOperation stickerPackOperation = 10;
-  optional MessageTimerRead     messageTimerRead     = 11;
+  optional ViewOnceOpen         viewOnceOpen         = 11;
 }
 
 message AttachmentPointer {
diff --git a/ts/types/Message.ts b/ts/types/Message.ts
index 32fe2e3daa..4fb2bbdf1a 100644
--- a/ts/types/Message.ts
+++ b/ts/types/Message.ts
@@ -18,7 +18,8 @@ export type IncomingMessage = Readonly<
     decrypted_at?: number;
     errors?: Array<any>;
     expireTimer?: number;
-    messageTimer?: number;
+    messageTimer?: number; // deprecated
+    isViewOnce?: number;
     flags?: number;
     source?: string;
     sourceDevice?: number;
@@ -47,7 +48,8 @@ export type OutgoingMessage = Readonly<
     body?: string;
     expires_at?: number;
     expireTimer?: number;
-    messageTimer?: number;
+    messageTimer?: number; // deprecated
+    isViewOnce?: number;
     recipients?: Array<string>; // Array<PhoneNumber>
     synced: boolean;
   } & SharedMessageProperties &
diff --git a/ts/types/message/initializeAttachmentMetadata.ts b/ts/types/message/initializeAttachmentMetadata.ts
index 42365dcb11..56d19d45e8 100644
--- a/ts/types/message/initializeAttachmentMetadata.ts
+++ b/ts/types/message/initializeAttachmentMetadata.ts
@@ -16,7 +16,7 @@ export const initializeAttachmentMetadata = async (
   if (message.type === 'verified-change') {
     return message;
   }
-  if (message.messageTimer) {
+  if (message.messageTimer || message.isViewOnce) {
     return message;
   }