There are many encryption standards in the digital world today, many of which have been shown to have fatal flaws. Unfortunately, many standards that are considered insecure are still being used in sensitive applications. One such standard is WEP. So what is it and why is it bad to use?
This is reminiscent of my high school days when our STEM Lab teacher would set up a few computers with Kali Linux installed. He also created a WEP Wi-Fi access point for the class. This was so that we could learn how to use Fern Wi-Fi Cracker and similar software to crack the insecure WEP access point and see how much harder WPA/WPA2-PSK access points were to crack. The WEP attack took maybe 5 minutes and was able to penetrate the network, all at the hands of a class of high schoolers. However, the WPA attacks required the use of a dictionary and never found the password to the network.
WEP is not a good encryption standard; however, it is better than no security. It encrypted all traffic to and from the access point using a static key, which was its downfall. This downfall can now be exploited by common, everyday computers. It is now recommended to use at least WPA, but how much longer until that can be cracked by everyday computers?
In wireless security, passwords are only half the battle. Choosing the proper level of encryption is just as vital, and the right choice determines whether your wireless LAN is a house of straw or a resilient fortress.
In addition to the risk of snooping and data breaches, threat actors can use unsecured wireless networks as a point of vulnerability to gain access to the broader enterprise network. Encryption doesn't necessarily solve this problem, but it's reasonable to expect that attackers who see a WLAN with outdated encryption protocols in place will begin poking around for other weak spots in the wireless network.
When choosing from among WEP, WPA, WPA2 and WPA3 wireless security protocols, experts agree WPA3 is best for Wi-Fi security. As the most up-to-date wireless encryption protocol, WPA3 is the most secure choice. Some wireless APs do not support WPA3, however. In that case, the next best option is WPA2, which is widely deployed in the enterprise space today.
Wi-Fi Alliance developed WEP -- the first encryption algorithm for the 802.11 standard -- with one main goal: prevent hackers from snooping on wireless data as it is transmitted between clients and APs. From its inception in the late 1990s, however, WEP lacked the strength necessary to accomplish this aim.
WEP uses the RC4 (Rivest Cipher 4) stream cipher for authentication and encryption. The standard originally specified a 40-bit, preshared encryption key. A 104-bit key later became available after the U.S. government lifted certain federal restrictions.
An administrator must manually enter and update the key, which combines with a 24-bit initialization vector (IV) in an effort to strengthen encryption. The small size of the IV increases the likelihood that users will recycle keys, however, making them easier to crack. This characteristic, along with several other security flaws and vulnerabilities -- including problematic authentication mechanisms -- makes WEP a risky choice for wireless security.
Although WPA is also based on RC4, it introduced several enhancements to encryption -- namely, the use of the Temporal Key Integrity Protocol (TKIP). TKIP contained a set of the following functions to improve WLAN security:
In 2017, Belgian security researcher Mathy Vanhoef discovered a major security flaw in WPA2, known as the key reinstallation attack (KRACK) vulnerability, which exploits the reinstallation of wireless encryption keys. While WPA2-Enterprise has a stronger authentication scheme due to its use of EAP -- compared to WPA2-Personal, which uses preshared keys -- the KRACK vulnerability exists at the encryption stage. As a result, it affects all WPA2 implementations.
A new Wi-Fi network connection begins with a cryptographic four-way handshake between an endpoint and AP in which both devices, through a series of back-and-forth messages, prove they know a preestablished authentication code -- PMK in enterprise mode and PSK in personal mode -- without either one revealing it explicitly. Upon authentication, the third step in the four-way handshake involves the AP passing a traffic encryption key to the client. If the endpoint doesn't acknowledge it has received the key, the AP assumes a connectivity issue, resending and reinstalling it repeatedly. KRACK attackers -- who must be within physical range of both client and network -- can trigger, capture, analyze, manipulate and replay those retransmissions until they're able to determine the key, break encryption and gain access to network data.
WPA3 mandates the adoption of Protected Management Frames, which help guard against eavesdropping and forging. It also standardizes the 128-bit cryptographic suite and disallows obsolete security protocols. WPA3-Enterprise has optional 192-bit security encryption and a 48-bit IV for heightened protection of sensitive corporate, financial and governmental data. WPA3-Personal uses CCMP-128 and AES-128.
WPA3 addresses WPA2's KRACK vulnerability with a more secure cryptographic handshake, replacing the PSK four-way handshake with Simultaneous Authentication of Equals (SAE), a version of the Internet Engineering Task Force's dragonfly handshake in which either client or AP can initiate contact. Each device then transmits its authentication credentials in a discrete, one-off message, instead of in a give-and-take, multipart conversation. Importantly, SAE also eliminates the reuse of encryption keys, requiring a new code with every interaction. Without open-ended communication between AP and client or encryption key reuse, cybercriminals can't as easily eavesdrop or insert themselves into an exchange.
SAE limits users to active, on-site authentication attempts -- flagging anyone who has exceeded a certain number of password guesses. This capability should make the typical Wi-Fi network more resistant to offline dictionary attacks. By mandating a new encryption passphrase for each connection, SAE also enables a feature called forward secrecy, which aims to prevent attackers who have cracked a passcode from using it to decrypt data they previously captured and saved.
Cracking WEP is fast and easy with commonly available Windows- or Linux-based tools. The length of the WEP key, 40- or 104-bit, is practically irrelevant, and with the software tools currently available, any novice can crack WEP in minutes given enough captured data. With users being added to the WLAN every day in most enterprises and the amount of data going over the WLAN growing exponentially, capturing enough data to crack WEP is often simple.The moral of the story with WEP is simply that it should never be used when stronger authentication and encryption mechanisms are available. Cracking WPA/WPA2-Personal (which uses a passphrase) is a much more difficult task than cracking WEP, but it still isn't an overwhelming task. Given the right dictionary file(s) and the latest versions of WPA cracking tools, cracking WPA/WPA2-Personal can happen in a short time if a very strong passphrase isn't used by the network administrator. The Wi-Fi Alliance suggests at least 20 characters with lower case, upper case, numbers, and special characters and use of WPA2 over WPA whenever possible.Tools such as Aircrack-ng can be easily used both for cracking WEP and WPA/WPA2-Passphrase. Since Aircrack-ng is available for Windows, it gives the ability to do sophisticated hacking to a novice. Use of WPA/WPA2-Personal should be limited to small installations such as SOHO - hence the name "Personal" - or very specific scenarios in SMB installations (like VoWLAN phones). When WPA/WPA2-Personal is used, it is best for only the network administrator to have the passphrase. He/she would enter it into every laptop, VoWLAN phone, handheld PC, or other wireless device manually without giving it to the user. Of course this is not scalable, but it's more secure than having 5-50 users knowing the passphrase.More secure alternatives to static WPA/WPA2-Personal passphrases have been developed, such as Ruckus Wireless's Dynamic PSK solution. More information on this solution can be found here: -dynamic-psk.pdf If you just can't bring yourself to make a strong passphrase, there are tools just for this purpose, such as Juiper's PassAmp utility (a free download) and the website: Having tools like these will help you get past the mental block of creating such strong passphrases.
Some of the significant changes implemented with WPA included message integrity checks (to determine if an attacker had captured or altered packets passed between the access point and client) and the Temporal Key Integrity Protocol (TKIP). TKIP employs a per-packet key system that was radically more secure than the fixed key system used by WEP. The TKIP encryption standard was later superseded by Advanced Encryption Standard (AES).
If all this thinking about Wi-Fi security and encryption has you curious about other tricks and techniques you can easily deploy to further secure your Wi-Fi network, your next stop should be browsing the following How-To Geek articles:
WEP was the only encryption protocol available to 802.11a and 802.11b devices built before the WPA standard, which was available for 802.11g devices. However, some 802.11b devices were later provided with firmware or software updates to enable WPA, and newer devices had it built in.
WEP was ratified as a Wi-Fi security standard in 1999. The first versions of WEP were not particularly strong, even for the time they were released, due to U.S. restrictions on the export of various cryptographic technology. These restrictions led to manufacturers restricting their devices to only 64-bit encryption. When the restrictions were lifted, the encryption was increased to 128-bit. Despite the introduction of 256-bit WEP, 128-bit remains one of the most common implementations. 2b1af7f3a8