Pavel Ignatov - Fotolia
In wireless security, passwords are only half the battle. Choosing the proper level of encryption is just as vital, and the right choice will determine whether your wireless LAN is a house of straw or a shielded fortress.
Most wireless access points (APs) come with the ability to enable one of three wireless encryption standards: Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA) or WPA2. Find out below which is best for your wireless security needs.
Enterprises can use this side-by-side comparison of the three security protocols to explore which one they should use in their wireless networks and when. This article also takes a deep dive into the history and technical details of WEP, WPA and WPA2.
WEP, WPA AND WPA2: Which is best?
When given the option among the WEP, WPA and WPA2 wireless security protocols, experts agree WPA2 is best for Wi-Fi security. With the exception of the WPA3 standard -- which is still growing in adoption after the Wi-Fi Alliance introduced it in 2018 -- WPA2 is the most prevalent and up-to-date wireless encryption protocol, making it the most secure choice.
Some wireless APs do not support WPA2, however. In that case, the next best option is WPA, which the Wi-Fi Alliance released in 2003 as a stopgap until WPA2 was ready for prime time the following year.
At this point, no one should use the original wireless security protocol, WEP, as it is outdated and makes wireless networks extremely vulnerable to outside threats. Network administrators should replace any wireless AP or router that supports only WEP with a newer device that's compatible with WPA, WPA2 or WPA3.
Wired Equivalency Privacy (WEP)
The 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 was transmitted between clients and APs. From its inception in the late 1990s, however, WEP lacked the strength necessary to accomplish this aim.
Cybersecurity experts identified several severe flaws in WEP in 2001, eventually leading to industrywide recommendations to phase out the use of WEP in both enterprise and consumer devices. After a large-scale cyberattack executed against T.J.Maxx in 2009 was traced back to vulnerabilities exposed by WEP, PCI DSS prohibited retailers and other entities that processed credit card data from using WEP.
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 was later made available after a set of restrictions from the U.S. government was lifted. The key must be manually entered and updated by an administrator.
The key is combined with a 24-bit initialization vector (IV) in an effort to strengthen the encryption. However, the small size of the IV increases the likelihood that keys will be reused, which, in turn, makes them easier to crack. This characteristic, along with several other vulnerabilities -- including problematic authentication mechanisms -- makes WEP a risky choice for wireless security.
Wi-Fi Protected Access (WPA)
The numerous flaws in WEP revealed the urgent need for an alternative, but the deliberately slow and careful processes required to write a new security specification posed a conflict. In response, in 2003, the Wi-Fi Alliance released WPA as an interim standard, while the Institute of Electrical and Electronics Engineers Inc. (IEEE) worked to develop a more advanced, long-term replacement for WEP.
WPA has discrete modes for enterprise users and for personal use. The enterprise mode, WPA-EAP, uses more stringent 802.1x authentication with the Extensible Authentication Protocol. The personal mode, WPA-PSK, uses preshared keys for simpler implementation and management among consumers and small offices. Enterprise mode requires the use of an authentication server.
Although WPA is also based on the RC4 cipher, it introduced several enhancements to encryption -- namely, the use of the Temporal Key Integrity Protocol (TKIP). TKIP contains a set of the following functions to improve wireless LAN security:
- use of 256-bit keys;
- per-packet key mixing, which generates a unique key for each packet;
- automatic broadcast of updated keys;
- message integrity check;
- larger IV size using 48 bits; and
- mechanisms to reduce IV reuse.
WPA was designed to be backward-compatible with WEP to encourage quick, easy adoption. Network security professionals were able to support the new standard on many WEP-based devices with a simple firmware update. This framework, however, also meant the security it provided was not as comprehensive as it could be.
Wi-Fi Protected Access 2 (WPA2)
As the successor to WPA, the WPA2 standard was ratified by the IEEE in 2004 as 802.11i. Like its predecessor, WPA2 also offers enterprise and personal modes. Although WPA2 still has vulnerabilities, it is considered the most secure wireless security standard available.
WPA2 replaces the RC4 cipher and TKIP with two stronger encryption and authentication mechanisms: the Advanced Encryption Standard (AES) and Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP), respectively. Also meant to be backward-compatible, WPA2 supports TKIP as a fallback if a device cannot support CCMP.
Developed by the U.S. government to protect classified data, AES comprises three symmetric block ciphers. Each encrypts and decrypts data in blocks of 128 bits using 128-, 192- and 256-bit keys. Although the use of AES requires more computing power from APs and clients, ongoing improvements in computer and network hardware have mitigated performance concerns.
CCMP protects data confidentiality by allowing only authorized network users to receive data, and it uses cipher block chaining message authentication code to ensure message integrity.
WPA2 also introduced more seamless roaming, allowing clients to move from one AP to another on the same network without having to reauthenticate, using Pairwise Master Key caching or preauthentication.
What's in a name? Wi-Fi 6 vs. 802.11ax
Delaying Wi-Fi upgrades increases security risks
Advice on optimizing your WLAN performance and reliability