Installing Sync

At the time of writing this book, there were a few repositories that kept this package
with the startup scripts. A word of warning: do not to trust sources other than the
ones that are enabled by default. People can easily alter code and place their own
version of the binary with some nasty backdoors. Go to the official website, or use
the links provided by the official website.

We will create a new directory, download the ARM version of Sync, and extract it,
as shown in the following command line snippet:

mkdir ~/.btsync && cd ~/.btsync
wget http://btsync.s3-website-us-east-1.amazonaws.com/btsync_arm.tar.gz
tar -zxvf btsync_arm.tar.gz
./btsync

You should see a message saying that Sync forked to the background. This means
that everything is running well. You can now navigate a browser on the same
network to your Pi's address: http://raspberrypi:8888/gui.

Add the recently created public directory, and copy the generated secret. Now, you
should go and install the application on your Mac OS X, Windows, or other Linux
machine. Use the secret that was generated on the Pi on other machines. It can detect
machines on the same network, which increases the speed of synchronization.

Sync tries its best to configure ports and use protocols to communicate over the
Internet. In theory, you can now call your friend on the phone, ask them to install
Sync, and e-mail them the secret. They will now start seeing the same files as you.

BitTorrent Sync uses external servers for tracking purposes, but no files
are stored on them.

BitTorrent Sync claims to use SRP for mutual authentication and Perfect

Forward Secrecy, in which all data is then encrypted with AES-128
Counter Mode and unique session keys. It is a very complex way to
ensure nobody can guess your key, even BitTorrent. It is all dynamically
generated on the fly, and then the clients negotiate more keys during
transfers. This sounds really good, but you would have to take them on
their word, as the project is closed source.