sudo apt-get install gcc e2fslibs-dev zlib1g-dev libssl-dev make
cd tarsnap-autoconf-1.0.31 (directory name corresponding to the downloaded tarball)
./configure && make && sudo make install
sudo tarsnap-keygen –keyfile /root/tarsnap.key –user username –machine machinename (note that my blog converts two dashes to a single long dash so you need to edit this line after cut & paste)