What actually is WLAN?

what is wireless security

WLAN (Wireless Local Area Network) is a wireless local network and is generally used when the network device can’t be wired or is difficult to implement, requiring a lot of effort. A wireless network can also exist for convenience reasons. Wireless connections are particularly widespread in the private sector, since they are a good solution for implementing internet access through entire living quarters without having to rely on cables. Radio networks are also useful in offices, especially when a variety of portable devices such as laptops, tablets, or smartphones are in use.

There are three different modes for operating wireless networks:

• Infrastructure mode: the structure of this mode is similar to the mobile network. A wireless access point takes care of the coordination of all network users and sends them small packets, at adjustable intervals, with information about the network name, the supported transmission rates, or the type of encryption. The access point is often a router.

• Wireless distribution system: since WLAN networks use the same addressing mode as Ethernet, you can easily connect to wired networks (or other wireless networks) via the access point. This is how networks are linked together and the range is increased, which is why this is known as a wireless distribution system.

• Ad-hoc mode: in ad-hoc networks, the central control unit is missing, which means that the coordination must be taken over by the respective terminals. These networks are used for fast, direct communication between individual participants. However, this WLAN mode isn’t used as frequently – alternative techniques, such as Bluetooth, are much more common.

These are the disadvantages of wireless networks

The outline data for communication in radio networks is specified in IEEE 802.11 from the Institute of Electrical and Electronics Engineers (IEEE) near New York. At the beginning, however, not much emphasis was placed on security: unencrypted transmission and no user authentication requirements meant that anyone within the appropriate area had access to a wireless network. Ultimately, the requirement of WLAN security promoted the development of the following encryption and authentication methods:

• Wired Equivalent Privacy (WEP): WEP is the oldest standard for WLAN encryption and dates back to 1997. It offers two authentication methods: Open System Authentication (enabled for all clients) and Shared Key Authentication (activated by password). In addition, WEP includes the encryption methods RC4. Due to various weaknesses, WEP is today considered unsafe and outdated.

• WLAN Protected Access (WPA): WPA builds on the WEP architecture and is designed to eradicate weaknesses in the same process. To ensure this, WPA operates with a dynamic key based on the Temporal Key Integrity Protocol (TKIP). Since WPA also has certain security deficiencies, new wireless access points (since 2011) and all WLAN-enabled devices (since 2012) are no longer allowed to support this protocol.

• WLAN Protected Access 2 (WPA2): the current, safest WLAN encryption and authentication method WPA2 was released in 2004 with the IEEE 802.11i standard. Instead of TKIP, WPA2 uses the much more modern AES encryption method. Therefore, if you set up a WLAN, you should always use the older WEP and WPA standards of WPA2.

• WLAN Protected Setup (WPS): the standard WPS is not a transmission nor encryption technique, but is rather an automatic configuration feature, which aims to make WLAN configuration easier for new network users. The authentication is carried out at the push of a button (WPS PBC) – physically at the access point or virtually via a software-implemented button – or by entering a PIN (WPS PIN). Alternatively, you can change the network settings via USB stick or via NFC (Near Field Communication).

Although WEP and WPA with WPA2 have a legitimate, more secure successor, some operators are still using these outdated standards – as long as they are supported by the wireless action point in order to encrypt their WLAN. Whether this is unintentional or for compatibility reasons (to grant access to older devices) is incidental. What is clear is that networks like this are at a high risk of unauthorized access – one of the main reasons for the critical assessment of WLAN security. Additional errors that make it easier for attackers to intercept data include:

• Having standard user names and passwords for wireless access points

• Having unsafe basic configurations for wireless access points

• Implementing WPA2 and WPS incorrectly

In addition, wireless networks are vulnerable to common DoS or DDoS attacks as well as so-called evil twin attacks. With the latter, malicious attackers plant fake wireless access points in the network with special firmware. Network users believe these to be real and then connect to them. The evil twin responds with its own authentication request and receives the WLAN access data from the unsuspecting network device. It also takes over the MAC address of the client (MAC spoofing), gaining all necessary data to establish the connection. Publicly accessible WLAN points are particularly at risk from this kind of attack.