Before the end of the month, the Wi-Fi Alliance, a nonprofit international association of wireless network vendors, will begin certifying products for the IEEE 802.11a and 802.11b wireless standards. The 802.11a standard allows 54 Mb per second on the 5-GHz radio spectrum, and the 802.11b standard allows 11 Mb per second on the 2.4-GHz spectrum. Even though products using these standards have been offered by vendors for some time, Wi-Fi will begin testing submitted products to ensure compatibility and interoperability in accord with the standards set by the IEEE 802.11 standard.

802.11 WLANs Growing in Number

The wireless LAN (WLAN), as specified by the 802.11 standard, is one of the hottest and most rapidly evolving technologies in networking since it was first proposed in 1997. Over the last year, an estimated 7 million WLAN nodes were put into operation, almost double the number from the previous year. These installations statistics include both commercial and home WLANs (a fast-growing consumer sector). The leading WLAN technology is now clearly based upon the 802.11 standard and holds over 70% of the market, outstripping the HomeRF technology that had previously been dominant. The HomeRF-based installations are estimated to have dropped to about 30% this year.

Security for 802.11 Still a Concern

However, since 9/11, concerns about WLAN security have gained increasing attention as individuals and corporations un-tether their devices from wired LANs to use their equipment for serious computing. Though the 802.11 standard identifies a security mechanism--called Wired Equivalent Privacy (WEP)--that prevents eavesdropping on the WLAN, many in the industry no longer feel this is enough. WEP uses a simple security key to provide access control.

Unfortunately, not long after WEP was introduced, its cryptographic weaknesses were exposed by a number of independent studies conducted by academic and commercial interests. According to these studies, third parties could hack WEP security relatively easily by using the right tools and by analyzing the WLAN traffic. These studies concluded that, while light home-use traffic would make it difficult for hackers to obtain enough data to analyze, a heavily used commercial WLAN would quickly provide the volume of raw traffic patterns to make analysis and hacking viable. This is not to say that WEP is useless: Despite its weaknesses, WEP is still considered strong enough for the casual user in home or office. However, its future as a security mechanism on heavily trafficked WLANs is clearly endangered.

Wi-Fi Protected Access Security

For this reason, several weeks ago Wi-Fi announced a security solution based on an IEEE standards effort called Wi-Fi Protected Access (WPA) to replace the existing WEP. WPA was developed by Wi-Fi with the direct involvement of the IEEE 802.11 standards engineering team. This solution is designed to work in the products on the market today and is expected to first appear in so-called "Wi-Fi Certified" products during the first quarter of 2003. Most vendors are expected to offer firmware and software updates for the Wi-Fi certified products currently in use.

WPA was designed to achieve a number of goals: strong, interoperable replacement of WEP; software upgradeability to WPA certified devices; applicability to both home and commercial WLANs; and quick availability to the market. To achieve these goals, WPA will provide a better data encryption mechanism called Temporal Key Integrity Protocol (TKIP) and a more stringent authentication mechanism called Extensible Authentication Protocol (EAP).

How TKIP and EAP Overcome WEP Failures

TKIP provides a per-packet key mixing function, a message integrity check (MIC) named Michael, an extended initialization vector (IV) with sequencing rules, and a re-keying mechanism--all things that were missing from the original WEP security mechanism.

To strengthen user authentication, WPA will implement the IEEE 802.1x security standard along with EAP. Working together, these implementations will provide a framework for stronger user authentication using a central authentication server--such as RADIUS--to authenticate each user on the network before they join it. It will also employ a "mutual authentication" protocol so that the wireless user doesn't accidentally join a rogue network that might steal its network credentials. These enhancements will more than make up for the failures in security designed in the original WEP authentication.

Forward Compatibility Ensures Current Marketability of WLAN Products

The best thing about WPA, however, is that it is designed to be forward-compatible with the burgeoning IEEE 802.11i security specification that is currently under development. WAP is considered a "subset" of the current 802.11i draft, taking certain pieces of the 802.11i draft that are currently ready to bring to market today (TKIP and 802.1x) and implementing them through firmware updates in currently certified equipment. (The complete IEEE 802.11i spec is scheduled for publication at the end of 2003.)

How WAP Provides Enterprise-Level Security

The requirements of enterprise-level security are clearly different than what is normally needed for the small office/home office (SOHO) user. However, Wi-Fi believes that WPA will fulfill enough of the security concerns of enterprises now to continue to spur implementation of WLANs at the enterprise level. How? In an enterprise with IT resources, WPA will be used in conjunction with other devices--such as an authentication server--that will provide centralized access control. In addition, using TKIP to encrypt data will narrow the WLAN's exposure to hackers. This is believed to be "secure enough" now, until the 802.11i specification is finished and implemented in 2003.

Small Office/Home Office Environments

In SOHO settings, where no authentication server will be present, WPA will run in a special "home" mode. This mode, called Pre-Shared Key (PSK), will allow the use of manually-entered authentication keys and passwords. It's designed to be easily set up by home users, requiring them to simply enter a master key to gain access to their wireless access point or their wireless gateway. Once entered, WPA takes over automatically, allowing only those devices with a matching password to join the network. This feature is designed to keep out eavesdroppers and other unauthorized users. In addition, the password automatically starts the TKIP encryption process, further raising the barrier to hackers.

WPA Public Access and Mixed-Mode Corporate Rollouts

In addition, WPA is designed to be useful for Wireless Internet Service Providers (WISPs) that are offering the Wi-Fi certified public access nodes where secure transmission is particularly important. Wi-Fi believes the authentication capability defined by WPA will be strong enough to enable a secure access for service providers and mobile users not utilizing virtual private network (VPN) connections.

However, just as important for large networks with a significant number of clients will be WPA's phased-in implementation capabilities. In a large wireless network, there are just too many devices to roll out a completely new security scheme at any given time. Consequently, WPA is designed to also operate in a "mixed mode," allowing the older WEP security mechanism to continue functioning on the same network where WPA upgrades have been implemented. In this manner, as users upgrade their security through software and firmware patches to their devices, the network itself continues to function--albeit, at a reduced security threshold.

Falling Prices on 802.11 Devices Mean Faster Acceptance in the Marketplace

With prices for 802.11a and 802.11b WLAN cards and access devices falling at astounding rates (street prices are now less than $100), the implementation of WLANs is speeding quickly. Combine that with the increase in bandwidth and the nominal cost of implementing a hardwired LAN, and the economic imperative of WLANs becomes easy to sell to management. The only missing piece has been an adequate security mechanism to overcome the weaknesses in the WEP, but this puzzle now seems to have been solved. With the onset of WAP and the future of the IEEE 802.11i standard just around the corner, it will not be long before those twisted, snaking network cables will be a thing of the past.

Thomas M. Stockwell is the Editor in Chief of MC Press, LLC. He has written extensively about program development, project management, IT management, and IT consulting and has been a frequent contributor to many midrange periodicals. He has authored numerous white papers for iSeries solutions providers. His most recent consulting assignments have been as a Senior Industry Analyst working with IBM on the iSeries, on the mid-market, and specifically on WebSphere brand positioning. He welcomes your comments about this or other articles and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..