On a Windows computer. But if you have a solution for Linux or Mac, I am happy to hear it.

I will pay money for it, as long as it works.

I need a solution to encrypt and then sync all my files to the cloud as offsite backup.

Here are my requirements:

  • Must have file versioning enabled in the cloud.

  • Must encrypt locally on my computer before being sent to the cloud.

  • Does not require me to create a virtual drive/folder on my hard drive and then drag and drop files to encrypt then back up. In other words, it encrypts current folders and files in my hard drive as I work on them. No drag and drop to a virtual drive/folder required.

  • Preferably strongest encryption algorithm used --- Perhaps Truecrypt ? EncFS? dm-crypt LUKS?

  • Preferably open source.

  • Preferably no Java.

To quote another person:

I'd love to see a fully open-source, zero knowledge, roll your own-solution, allowing it to be hosted on offsite VPS! I think this would pretty much solve the problem of cloud storage.

What would you recommend?

TL:DR: Please recommend a solution that can encrypt then sync to ANY cloud storage of my choosing, including Tencent or Kanbox (10 TB free).

Right now, for your information, I am aware of these back up clients and the cloud they can sync to. Unfortunately, none of them can sync to any cloud storage of my choosing:

SyncBackPro, Arq for Windows and Arq for Mac, Syncovery, Duplicati, BitTorrent, Sync, Strongsync, ExpanDrive, CloudBerry, CloudBacko, Filement, GoodSync, Boxcryptor.

I think it has something to do with the necessary use of the REST API from cloud storage. See this post.


  • both spideroak.com and mega.co.nz offer end to end encryption, but not versioning. DropBox offers versioning, but you would have to encrypt it yourself. I look forward to an answer to this question, as I would like one too.
    – Mawg
    Commented Aug 14, 2015 at 7:04
  • 1
    I like this question too, I usually end up .7z with password into dropbox Commented Aug 14, 2015 at 14:54

3 Answers 3


It could be well worth taking a look at git-annex - you mark the remote storage for one of several types of encryption and it will sync your files as and when.

Currently, August 2015, built in support for:

  • Amazon S3
  • Amazon Glacier
  • Internet Archive via S3
  • Box.com
  • Google drive
  • Google Cloud Storage
  • Mega.co.nz
  • SkyDrive
  • OwnCloud
  • Flickr
  • IMAP
  • Usenet
  • chef-vault
  • hubiC
  • pCloud
  • ipfs

Since it is Free and Open Source if you want to add support for something else you can write your own in Haskell or the language of your choice!

  • Free - gratis & open source
  • Windows, Mac OS-X, Linux & potentially anywhere that you have Haskell available.
  • Thanks a million. I will look into it. At last, some light at the end of the tunnel.
    – goughgough
    Commented Aug 16, 2015 at 10:45

As per Solutionhunter post at Reddit thread, you can try:

  • SyncBackPro

    Google Drive, Office 365 (OneDrive for Business and SharePoint), OneDrive, Box, Dropbox, SugarSync , Amazon Glacier S3 , Amazon Cloud , Google Storage and Microsoft Azure support.

  • Arq, for Windows and Mac

    Amazon Cloud Drive, Amazon Web Services, Dropbox, Google Drive, Google Cloud Storage, or OneDrive account.

  • Syncovery

    Features comparison Supports various Internet protocols, including FTP, FTPS, SFTP/SSH, WebDAV, SSL, HTTP, as well as these cloud services: Amazon S3 and compatible services, Microsoft Azure, Rackspace Cloud Files, Microsoft OneDrive (formerly SkyDrive), Google Drive and Google Docs, DropBox, Box.com, and more....Sugarsync

  • Duplicati (check wiki page

    Duplicati supports not only various online backup services like OneDrive,1 Amazon S3, Rackspace Cloud Files, Tahoe LAFS, Google Docs but also any servers that support SSH/SFTP, WebDAV, or FTP. Duplicati is a backup client that securely stores encrypted, incremental, compressed backups on cloud storage services and remote file servers. It works with Amazon S3, Windows Live SkyDrive, Google Drive (Google Docs), Rackspace Cloud Files or WebDAV, SSH, FTP (and many more). Duplicati is open source and free.

  • BitTorrent Sync

    Sync easily moves anything, anywhere - all the benefits of the cloud, none of the limitations. Available for Windows, Mac, Linux, iOS, and Android.

  • Strongsync/Strongysnc

    Control your data. Strongsync lets you connect to your own SFTP server or Amazon S3 account so you stay in complete control of your data. Strongsync is a Mac/Windows app providing Dropbox-like sync and backup to DreamObjects......

  • ExpanDrive

    ExpanDrive creates a virtual USB drive that connects to all major cloud storage providers such as Dropbox, Google Drive, Box, OneDrive, Openstack Swift, Amazon S3 or your own SFTP, FTP or WebDAV server.

  • CloudBerry

    Online cloud backup and storage management solutions powered by Amazon S3, Glacier, Microsoft Azure, Google Cloud and designed for SMBs and MSPs. --- Avoid Cloud Vendor Lock-In With Cloudberry you are free to choose optimal storage for your backups. Don't be locked in with a backup service and paying 2x times more for the backup storage. With over 20 supported cloud storage destinations, CloudBerry Backup give you freedom of choice, ensuring data accessibility and portability. Featured Cloud Providers Amazon S3 Amazon Glacier Microsoft Azure Google Cloud Storage Rackspace Cloud Files OpenStack HP Cloud IBM SoftLayer Google Drive Other Cloud Providers Google Nearline Storage Eucalyptus Clodo Scality Cloudian DreamObjects Cloud Storage Aruba Cloud Hitachi Content Platform ThinkOn IDC Frontier LeoNovus CloudWatt HavenCo Tiscali SFR Lunacloud CenturyLink Enter Cloud Suite QNAP Google Drive HP Helion

  • CloudBacko

    "Backup all servers, databases, virtual machines & workstations Need a cloud / online / offsite / remote / local backup solution for backing up Microsoft Exchange Server (EDB and mail level backups), Microsoft SQL Server, VMware vSphere ESXi (both Paid and Free versions), Hyper-V, Lotus Domino, Lotus Notes, Oracle Database, MySQL, Windows System, Windows System State, as well as Files in desktops and laptops? CloudBacko supports them all."

  • Filement

    Filement provides users with the ability to manage all their devices (PCs, Macs and Linux, Smartphones, Tablets, Smart Routers), cloud and remote services (Google Drive, Dropbox, OneDrive, Rackspace, FTP ect.).

  • GoodSync: File Sync & Backup Software

    Features: Backup and sync your files with ease using GoodSync. Our simple and secure software will ensure that you never lose your files. Download GoodSync Free ... --- Supports: Cloud Server Folders Amazon S3 Dropbox FTP Google Drive (Docs) OneDrive by MS OneDrive Pro (Sharepoint) by MS Office365 by MS SkyDrive by MS SFTP (SSH) WebDAV Windows Azure by MS (Source: January 2015 3rd party backup software options)

  • Boxcryptor

    With Boxcryptor you can encrypt your files on Dropbox, Google Drive, Microsoft OneDrive, SugarSync, Box and many other storage providers. It also supports all the clouds that use the WebDAV standard such as Cubby, Strato HiDrive, and ownCloud.

  • Storage Made Easy (wiki page)


Here are few Dropbox alternatives with end-to-end client-side encryption:

  • Seafile (GitHub)

    It’s sort of a DropBox clone, but both the server and the client are completely open source. As if that wasn’t enough, it supports, optionally, end-to-end client-side encryption.

  • SpiderOak (GitHub)

    This is probably the most well-known Dropbox alternative that supports end-to-end encryption. It’s even been name-dropped by Edward Snowden, which is high praise in these circles.

    Although SpiderOak as a company has a solid reputation, and has released a number of open source encryption-related software packages, the SpiderOak client itself is closed-source. This means we have nothing more than SpiderOak’s word that their client is indeed performing the end-to-end encryption in a secure way, and is not adding some backdoor key to every packet passing from your computer to their servers.

  • Mega (GitHub page, read also wiki page)

    Mega does end-to-end encryption, and its client is open source.

  • Syncany + Dropbox (GitHub)

    An open-source cloud storage and filesharing application. Securely synchronize your files to any kind of storage!

Some other (closed sourced):

  • Wuala

    End-to-end encrypted file syncing service, this one from Switzerland. It’s called Wuala, and it belongs to La Cie, which belongs to Seagate, a US company.

  • CrashPlan

    Data protection service for Small Business provides peace of mind through easy-to-use, unlimited automatic data backup and recovery.

  • Tresorit

    End-to-end encrypted file sync & sharing for teams who want to protect confidential data. Keep control of your files even after sharing by managing access and permissions.

  • pCloud

    Available for Windows, Mac, Linux & portable devices, based in Switzerland with optional encryption, can sync any folder and be used as a Virtual Drive.

  • Resilio

    Sync any folder to all your devices. Sync photos, videos, music, PDFs, docs or any other file types to/from your mobile phone, laptop, or NAS.

  • Pydio

    Modern file management platform built according to your business needs and regulations, Pydio is an open-source software deployed on your servers or wherever you decide. Securely connect all your files, teams and devices in one place.

  • Boxcryptor

    With Boxcryptor you can encrypt your files on Dropbox, Google Drive, Microsoft OneDrive, SugarSync, Box and many other storage providers. It also supports all the clouds that use the WebDAV standard such as Cubby, Strato HiDrive, and ownCloud.

  • AeroFS

    AeroFS does not store your data, we sync it. Get easy, secure file sync and share & collaboration for your enterprise today.

  • Tonido

    For Home: Tonido Server allows you to access all your files on your computer from a web browser, smartphone, tablet or even DLNA enabled devices. Simple setup. Start your own Personal Cloud in minutes.

    For Business: FileCloud allows you to run your own private cloud storage and sync solution for your employees, customers and clients.

  • SparkleShare

    SparkleShare creates a special folder on your computer. You can add remotely hosted folders (or "projects") to this folder. These projects will be automatically kept in sync with both the host and all of your peers when someone adds, removes or edits a file.

Source: Notes on full-time testing of 7 Dropbox alternatives.

For more solutions, check:

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