Dropbox, SkyDrive, Google Drive and so on all make it easy for one to sync a folder of files between multiple computers and devices. They all have one thing in common in that they store your files on their servers. Despite all the advantages they provide such as regular backups and previous versions, they all have a small storage limit (typically 2GB to 5GB) and charge a hefty premium for annual subscriptions. For example a 100GB Dropbox account is $99/year per user, which quickly adds up, such as for a team of users working on a project.
BitTorrent Inc. has developed a new free application, BitTorrent Sync, that securely syncs folders between multiple devices, but works totally independent of third party servers. The application uses the powerful BitTorrent protocol to efficiently sync files between devices. Like a file shared on BitTorrent, the more devices you have online to sync with, the faster and more efficiently it works, but like Dropbox, new and changed files are synced automatically.
To set up the BitTorrent Sync, the user just needs to install the application, pick a folder to share, generate a Shared secret and repeat this process on each device using the same shared secret. Like a Zip file password or Wi-Fi passphrase, the application uses the shared secret to generate the encryption key so that files are securely synced.
This application also offers several advantages over the commercial cloud-storage providers. No third party can snoop at the files the user is syncing between its devices, unless the user reveals its shared secret key. There is no storage limit on the size of the folder that can be synced, which is a big plus for those who need to sync a huge amount of data, such as video footage. As there is no user account involved, there is no risk of the user losing access to its account, let alone any other service tied with that account, such as this earlier incident.
As BitTorrent Sync is decentralised, there are a few drawbacks that the user will need to watch out for. At least two devices need to be online for files to sync. For example, if the user syncs files between a home PC and laptop, the PC must remain on for the files to sync to the laptop and vice versa. To get an "Earlier versions" like feature, the user needs to have at least one regularly online device that keeps a history of files, such as a Windows 7 PC with "Previous Versions" enabled on the drive letter with the shared folder.
One workaround to ensuring there is always one device online to sync with is by setting up a PC dedicated to running BitTorrent Sync. If the OS keeps a file history (e.g. “Previous Versions” feature in Windows 7), the user just needs to ensure this is enabled to keep previous versions of files and also schedule a regular backup to an external drive, such as with Windows' own Backup utility. For a workplace, this could easily be done using an existing server or giving life to an old PC to run the BitTorrent Sync application. Adding redundancy is as simple as repeating this process with another PC, preferably at least one PC in every office if the business has multiple offices.
The BitTorrent Sync application is currently in the Alpha stage of development and is available to invites for Windows, OS X, Linux and can be run on certain NAS devices.
