You are without doubt already familiar with the Tor project. The Tor browser is already a very handy tool to surf anonymously, but what if we had an entire network's traffic forwarded through Tor via a special gateway? Let's transform a tiny router in a transparent Tor proxy, a portable Wifi access point redirecting all traffic to the Tor network!
Let's begin with a short presentation of one of my favorite hackable network devices: the TL-MR3020.
Despite being marketed as a portable 3G/4G wireless N router, it does not possess any kind of mobile telecommunication interface. Instead, it's a very small and cheap router featuring a 802.11n 150Mbps Wifi interface, a 100Mbps ethernet port, and a USB port. It is powered over a mini-B USB port and it has an extremely low power consumption with an average current draw around 120mA at 5V, i.e. 600mW. Its hardware is pretty limited: an Atheros AR9331 SoC with a 400MHz MIPS processor, 32MB of RAM, and 4MB of flash memory.
The preliminary step for our Tor box is to install OpenWRT (this example uses Barrier Breaker) so we have a …