diff --git a/SignalServiceKit/src/Storage/OWSBackupStorage.h b/SignalServiceKit/src/Storage/OWSBackupStorage.h
new file mode 100644
index 000000000..85623096c
--- /dev/null
+++ b/SignalServiceKit/src/Storage/OWSBackupStorage.h
@@ -0,0 +1,37 @@
+//
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//
+
+//
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//
+#import "OWSPrimaryStorage.h"
+#import "OWSStorage.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+// void runSyncRegistrationsForStorage(OWSStorage *storage);
+// void runAsyncRegistrationsForStorage(OWSStorage *storage);
+
+@interface OWSBackupStorage : OWSStorage
+
+- (instancetype)init NS_UNAVAILABLE;
+
+//+ (instancetype)sharedManager NS_SWIFT_NAME(shared());
+//
+- (YapDatabaseConnection *)dbConnection;
+//
+//+ (nullable NSError *)migrateToSharedData;
+//
+//+ (NSString *)databaseFilePath;
+//
+//+ (NSString *)legacyDatabaseFilePath;
+//+ (NSString *)legacyDatabaseFilePath_SHM;
+//+ (NSString *)legacyDatabaseFilePath_WAL;
+//+ (NSString *)sharedDataDatabaseFilePath;
+//+ (NSString *)sharedDataDatabaseFilePath_SHM;
+//+ (NSString *)sharedDataDatabaseFilePath_WAL;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Storage/OWSBackupStorage.m b/SignalServiceKit/src/Storage/OWSBackupStorage.m
new file mode 100644
index 000000000..8e279baf7
--- /dev/null
+++ b/SignalServiceKit/src/Storage/OWSBackupStorage.m
@@ -0,0 +1,221 @@
+//
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//
+
+#import "OWSBackupStorage.h"
+
+//#import "AppContext.h"
+//#import "OWSAnalytics.h"
+//#import "OWSBatchMessageProcessor.h"
+//#import "OWSDisappearingMessagesFinder.h"
+//#import "OWSFailedAttachmentDownloadsJob.h"
+//#import "OWSFailedMessagesJob.h"
+//#import "OWSFileSystem.h"
+//#import "OWSIncomingMessageFinder.h"
+//#import "OWSMessageReceiver.h"
+#import "OWSStorage+Subclass.h"
+
+//#import "TSDatabaseSecondaryIndexes.h"
+//#import "TSDatabaseView.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+NSString *const OWSBackupStorageExceptionName_CouldNotCreateDatabaseDirectory
+    = @"OWSBackupStorageExceptionName_CouldNotCreateDatabaseDirectory";
+
+#pragma mark -
+
+@interface OWSBackupStorage ()
+
+@property (nonatomic, readonly, nullable) YapDatabaseConnection *dbConnection;
+
+@property (atomic) BOOL areAsyncRegistrationsComplete;
+@property (atomic) BOOL areSyncRegistrationsComplete;
+
+@end
+
+#pragma mark -
+
+@implementation OWSBackupStorage
+
+//+ (instancetype)sharedManager
+//{
+//    static OWSBackupStorage *sharedManager = nil;
+//    static dispatch_once_t onceToken;
+//    dispatch_once(&onceToken, ^{
+//        sharedManager = [[self alloc] initStorage];
+//
+//#if TARGET_OS_IPHONE
+//        [OWSBackupStorage protectFiles];
+//#endif
+//    });
+//    return sharedManager;
+//}
+
+- (instancetype)initStorage
+{
+    self = [super initStorage];
+
+    if (self) {
+        _dbConnection = self.newDatabaseConnection;
+
+        OWSSingletonAssert();
+    }
+
+    return self;
+}
+
+- (void)resetStorage
+{
+    _dbConnection = nil;
+    //    _dbReadWriteConnection = nil;
+
+    [super resetStorage];
+}
+
+- (void)runSyncRegistrations
+{
+    runSyncRegistrationsForStorage(self);
+
+    // See comments on OWSDatabaseConnection.
+    //
+    // In the absence of finding documentation that can shed light on the issue we've been
+    // seeing, this issue only seems to affect sync and not async registrations.  We've always
+    // been opening write transactions before the async registrations complete without negative
+    // consequences.
+    OWSAssert(!self.areSyncRegistrationsComplete);
+    self.areSyncRegistrationsComplete = YES;
+}
+
+- (void)runAsyncRegistrationsWithCompletion:(void (^_Nonnull)(void))completion
+{
+    OWSAssert(completion);
+
+    runAsyncRegistrationsForStorage(self);
+
+    DDLogVerbose(@"%@ async registrations enqueued.", self.logTag);
+
+    // Block until all async registrations are complete.
+    //
+    // NOTE: This has to happen on the "registration connection" for this
+    //       database.
+    YapDatabaseConnection *dbConnection = self.registrationConnection;
+    OWSAssert(self.registrationConnection);
+    [dbConnection flushTransactionsWithCompletionQueue:dispatch_get_main_queue()
+                                       completionBlock:^{
+                                           OWSAssert(!self.areAsyncRegistrationsComplete);
+
+                                           DDLogVerbose(@"%@ async registrations complete.", self.logTag);
+
+                                           self.areAsyncRegistrationsComplete = YES;
+
+                                           completion();
+                                       }];
+}
+
++ (void)protectFiles
+{
+    // TODO:
+
+    //    DDLogInfo(
+    //        @"%@ Database file size: %@", self.logTag, [OWSFileSystem
+    //        fileSizeOfPath:self.sharedDataDatabaseFilePath]);
+    //    DDLogInfo(
+    //        @"%@ \t SHM file size: %@", self.logTag, [OWSFileSystem
+    //        fileSizeOfPath:self.sharedDataDatabaseFilePath_SHM]);
+    //    DDLogInfo(
+    //        @"%@ \t WAL file size: %@", self.logTag, [OWSFileSystem
+    //        fileSizeOfPath:self.sharedDataDatabaseFilePath_WAL]);
+    //
+    //    // Protect the entire new database directory.
+    //    [OWSFileSystem protectFileOrFolderAtPath:self.sharedDataDatabaseDirPath];
+}
+
+//+ (NSString *)legacyDatabaseDirPath
+//{
+//    return [OWSFileSystem appDocumentDirectoryPath];
+//}
+//
+//+ (NSString *)sharedDataDatabaseDirPath
+//{
+//    NSString *databaseDirPath = [[OWSFileSystem appSharedDataDirectoryPath]
+//    stringByAppendingPathComponent:@"database"];
+//
+//    if (![OWSFileSystem ensureDirectoryExists:databaseDirPath]) {
+//        OWSRaiseException(
+//            OWSBackupStorageExceptionName_CouldNotCreateDatabaseDirectory, @"Could not create new database
+//            directory");
+//    }
+//    return databaseDirPath;
+//}
+
++ (NSString *)databaseFilename
+{
+    return @"SignalBackup.sqlite";
+}
+
+//+ (NSString *)databaseFilename_SHM
+//{
+//    return [self.databaseFilename stringByAppendingString:@"-shm"];
+//}
+//
+//+ (NSString *)databaseFilename_WAL
+//{
+//    return [self.databaseFilename stringByAppendingString:@"-wal"];
+//}
+//
+//+ (NSString *)legacyDatabaseFilePath
+//{
+//    return [self.legacyDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename];
+//}
+//
+//+ (NSString *)legacyDatabaseFilePath_SHM
+//{
+//    return [self.legacyDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename_SHM];
+//}
+//
+//+ (NSString *)legacyDatabaseFilePath_WAL
+//{
+//    return [self.legacyDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename_WAL];
+//}
+//
+//+ (NSString *)sharedDataDatabaseFilePath
+//{
+//    return [self.sharedDataDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename];
+//}
+//
+//+ (NSString *)sharedDataDatabaseFilePath_SHM
+//{
+//    return [self.sharedDataDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename_SHM];
+//}
+//
+//+ (NSString *)sharedDataDatabaseFilePath_WAL
+//{
+//    return [self.sharedDataDatabaseDirPath stringByAppendingPathComponent:self.databaseFilename_WAL];
+//}
+
+//+ (NSString *)databaseFilePath
+//{
+//    DDLogVerbose(@"%@ databasePath: %@", self.logTag, OWSBackupStorage.sharedDataDatabaseFilePath);
+//
+//    return self.sharedDataDatabaseFilePath;
+//}
+//
+//- (NSString *)databaseFilePath
+//{
+//    return OWSBackupStorage.databaseFilePath;
+//}
+
+//+ (YapDatabaseConnection *)dbReadConnection
+//{
+//    return OWSBackupStorage.sharedManager.dbReadConnection;
+//}
+//
+//+ (YapDatabaseConnection *)dbReadWriteConnection
+//{
+//    return OWSBackupStorage.sharedManager.dbReadWriteConnection;
+//}
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Storage/OWSPrimaryStorage.m b/SignalServiceKit/src/Storage/OWSPrimaryStorage.m
index d23b6fa37..d894aad84 100644
--- a/SignalServiceKit/src/Storage/OWSPrimaryStorage.m
+++ b/SignalServiceKit/src/Storage/OWSPrimaryStorage.m
@@ -58,6 +58,7 @@ void runAsyncRegistrationsForStorage(OWSStorage *storage)
 }
 
 #pragma mark -
+
 @interface OWSPrimaryStorage ()
 
 @property (nonatomic, readonly, nullable) YapDatabaseConnection *dbReadConnection;