Lesson 3: Networking Layer

Lesson describes threats to personal privacy at the networking layer: tracking, data theft, personally identifiable data (PII).

The Networking Layer connects your device – mobile, tablet, laptop, or desktop – to a network, be it the internet or any number of other wired or wireless connections available within proximity of your device.

The network layer is the most important of all to get right, because if you are not sending or receiving data to or from outside networks (assuming no-one else has physical access to your system), then by definition you have a private network. Many of the most secure private systems that occur on earth are in remote locations or buried in old mines or bunkers. There, completely isolated from all wireless signals, the operators of the facilities seek to preserve what is known as an “air-gap”. Air-gapping is a network layer security measure employed to ensure that a secure computer network is physically isolated from all other networks.

If, however, you need to connect to the internet, as most everyone does in order to function from day to day, one of the best ways to secure your communications at the network layer is via the use of a VPN or Virtual Private Network, which we go into in detail in Module 7.

There are, however, a number of other Network Layer leakages that can occur that you might want to be aware of.

As mentioned earlier, when many devices are switched on, even when they are in standby mode, they are constantly scanning and communicating with other wireless devices within radio proximity. Your device, with its unique identifiers, can be transmitting your location to other devices which can and do relay that information back to the internet.

If you are serious about preventing your device from contacting the outside (or protecting your device from the effects of EMP or electromagnetic pulse), you can create a device known as a Faraday Cage. A Faraday cage will effectively block all electromagnetic signals in and out of its confines. Instructions for how to make a DIY Faraday cage are easy to find online.

Another essential element you will want to consider at the Network Layer is your router. Your router is the box that sits in the corner of your home that most people these days connect to wirelessly. When you ask someone for the wifi password you are actually asking to be granted assess to their router. All devices must connect to a router in order to connect the internet, as routers are responsible for handling and directing IP traffic.

The following graphic is an excellent resource which outlines the most basic steps for securing your router to significantly boost your security at the Network Layer:

Another great resource is Router Security, where you can learn a lot more about how to secure your router.