Network Security

02.06.2016 |

Episode #7 of the course Cyber security basics by FutureLearn


Most of us trust that the information we access online, such as web pages and messages, are private, but have you ever considered how information is kept secure as it travels around the internet? This is the premise of network security. Behind the scenes, the internet is composed of a hierarchy of individual networks connected to one another. These networks range from local area networks (LANs) common in businesses and universities to telephone and data networks that link cities and countries by fiberoptic cables and satellite links.

Wired network access is more controllable because data is contained within cabling. With wireless networks, however, data is transferred through radio waves in the air, which anyone can potentially access and intercept if they are in range. In order to protect wifi networks from unauthorized users and ensure that the information we send and receive is secure, a number of security mechanisms have been developed since wifi was introduced. The most common methods are based on encryption, using a key known only to the nodes in the wireless network. Encryption scrambles sensitive information as it travels over networks. Once the information reaches its intended target, the encrypted information is safely transformed back into the original information.

The current recommended encryption mechanism you can use on home wifi networks is “Wifi Protected Access 2” (WPA2), which uses a more secure key to encrypt the transmitted data than previous encryption methods. This security mechanism has become the default configuration for wifi networks, but if your computer isn’t already using it, it’s a good step to take to make your wifi secure. Most wifi devices (including computers, routers, and phones) support several security standards; check your router’s menus or manual to find out how to set up WPA2. Outside of the home, be wary of any free wifi networks you join. In cafes, hotels, and train stations, for example, networks are typically “open,” which means information can be intercepted far more easily. For simple web browsing, this is fine, but it’s not the time to be accessing sensitive information, such as online banking.

A firewall is another common security measure used in network security. A firewall is a software program or piece of hardware that can help to protect your computer from malware. Think of it as a barrier and first line of defense between the internet and your own computer or network, protecting you against hackers, viruses, and worms attempting to reach your computer. Often, computers come with an in-built firewall that is switched on by default in some of the latest Windows operating systems. You can also install your own firewall, which comes in some internet security packages and in standalone software you can download (often for free from a trusted provider) online.


Recommended free course

Introduction to Cyber Security


Recommended book

“Spam Nation: The Inside Story of Organized Cybercrime-from Global Epidemic to Your Front Door” by Brian Krebs


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