From a corner of the vendor room at Defcon 20, a repurposed van sporting a "Ninja Tel" logo and a 12-foot cell phone tower broadcasts a GSM signal. It's available only to attendees lucky enough to score a Ninja Phone from the Ninja hacker group.
There's more than just a standard GSM network powering the Ninja Tel network. Ninja Tel uses a little-known feature of Android 4.0 Ice Cream Sandwich that allows networks to route calls over GSM or onto Wi-Fi, if the Wi-Fi has been configured properly using Session Initialization Protocol (SIP) and has a SIP Server.
The Ninja Tel network operations techs are a rotating team of Ninja members who ensure that the network stays up. In a room full of hackers, that's no simple task. At one point on Saturday morning, they stopped one of the estimated 13,000 people at Defcon from blocking the single-tower signal.
People who received a special Ninja Tel card could take it to this table next to the Ninja Tel operations van and exchange it for a Ninja Phone, which is a black HTC One V with a redecorated "chin" that reads "Ninja Tel" in gold with a shuriken logo and the Pac Bell font. Since the phone is the Ninja badge for Defcon 20, and you can't wear a phone (yet), the box also comes with military tags emblazoned with the Ninja logo in red and white to get you into the exclusive Ninja party.
The phone will grant access to the vending machine in the background during the Saturday night Ninja Party, but is inactive and only on display on the Defcon floor.
The Ninja Phone is an HTC One V, running a custom flavor of Android 4.0.3 called Ninja OS. A custom SIM card connects it to the Ninja Tel network, and after Defcon 20 closes, the network will cease to exist. The phone can be wiped and restored with any version of Android, and takes a SIM card for any standard GSM network like AT&T or T-Mobile.
After turning it on, the Ninja Phone shows the Ninja Tel shuriken logo. The next screen is a list of sponsors: Facebook, Zynga, Lookout Mobile Security, and AllJoyn. AllJoyn is an open-source messaging protocol that can be built into an app, so it can run on any operating system.
The Ninja Phone comes with five pages of pre-loaded apps, hidden behind a Yellow Pages-themed interface. When you dial the operator, you'll get a live person -- another Ninja Tel person. Some of the operators have been friendly voices, while others have been... snarkier.
Other apps include Eliot's Vending Services, which allows Ninja Phone owners to interact with the previously-mentioned vending machine at the Ninja party; the Ninja game, a customized version of junken (or ro-sham-bo for all you non-Ninjas); OKNinja, a ninja chatting service powered by AllJoyn; and a direct line to the Android IDE so that hackers can write their own apps for the phone.
The Ninja Phones can be sideloaded with standard Android apps, such as Lookout's flagship mobile security app.
The Ninja Tel project's aesthetics have been well-executed. From the etched glass throwing star logo in the van's control room, to the graphic design in the Ninja OS by artist Pinguino, Ninja Tel looks professional.
Interestingly, the project could have some serious real-world implications as proof that it's possible to create small-scale alternative, private communication networks.