Sync files between devices with Syncthing

Many tools and services are available for synchronizing data among various devices. Users who want to trust their data to the cloud can use services such as Google Drive, Dropbox, and Copy.com. An alternative here is BitTorrent Sync [1], which is a distributed peer-to-peer system based on the BitTorrent Sync protocol. This software, however, is not open source, just freeware. Thus, it is never clear what the program does. Syncthing, on the other hand, offers a secure alternative; it is open source and comes with a Mozilla Public license.

Syncthing uses the open source Block Exchange Protocol (BEP) [3] for synchronization. The data exchange among the individual nodes is typically TLS encrypted including Perfect Forward Secrecy (PFS). The nodes identify themselves to each other with cryptographic certificates, which Syncthing creates when it is installed on a platform. Encryption can be turned off for synchronization on a local network. This option speeds up the data throughput. In the basic setting, the program restricts encryption to metadata only. Written in the Go programming language, Syncthing has all of the required features for keeping your data secure.

Preparations

This relatively new software runs on Linux, Mac OS X, Windows, Solaris, various BSD versions, and also on the Raspberry Pi. A Sync app is available for Android, and the developers are working on a version for iOS. Listing 1 contains commands for adding the repository to Ubuntu and installing Syncthing. For testing, we also installed Syncthing on an openSUSE box to have something to sync with. For the curious, Syncthing is a default package in openSUSE Tumbleweed, and all you need to do is:

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