Home > Articles

Wi-Fi Protected Access (WPA), WPA2 and 802.11i

  • Print
  • + Share This
Like this article? We recommend

Here's an exclusive excerpt from the forthcoming new book: Upgrading and Repairing Networks, 5th Edition. Available in Spring 2006!

Wi-Fi Protected Access (WPA), WPA2 and 802.11i

In response to the vulnerability and criticism of WEP, the Wi-Fi Alliance created the Wi-Fi Protected Access (WPA) standard in 2003. WPA was designed to be an interim security solution until the completion of the IEEE 802.11i security standard, and its features are a blend of features originally developed for WEP and those being developed for 802.11i.

Like WEP, WPA uses RC4 encryption for its keys, but unlike WEP, WPA modifies the original key for greater security and supports an optional authentication server. WPA is the minimum recommended security standard for network hardware that supports it, such as 802.11g hardware that supports the full 802.11g standard, and most recent 802.11a hardware. Although some vendors of 802.11b hardware have provided upgrades to support WPA, most 802.11b hardware is not compatible with WPA security.

One of the main complaints about WEP, besides its limited-length keys, is the fact that the same key is used by both sides of the transmission, and the key does not change during a session. These factors make it easy to examine network traffic on a wireless network and eventually crack the encryption key.

WPA solves two problems associated with the earlier WEP security mechanisms. First, it uses encrypted techniques for authentication, which should assist in preventing unauthorized clients from becoming part of the wireless network. Second, it uses a constantly changing key instead of the single shared key used for encryption by WEP. By changing in the encryption key at frequent intervals, WPA can be much more difficult to crack. The constant changing of encryption keys is known as the Temporal Key Integrity Protocol (TKIP). This key-changing method will make it very difficult for intruders to decipher keys used by your wireless network, especially when compared to the static keys known by both sides of the communications link used by the simple WEP standards.

WPA also includes an integrity check that is basically a check sum based on the network packet that can detect whether a packet is originating from a valid network user or an intruder who is attempting to crack the key used by your network. Thus, if an unauthorized user uses the standard techniques to attempt to determine a fixed key, you can detect these intrusion attempts, and then deal with them.

Overcoming Potential Vulnerabilities in WPA

The version of WPA used in SOHO and small-business networks that lack an authentication server is known as WPA-Personal. The encryption key is known as a Pre-Shared Key (PSK); the PSK must be provided by a network client before it can log into a WPA-based wireless network. The original PSK is encrypted using a process known as Temporal Key Integrity Protocol (TKIP), which changes the key repeatedly during a connection to help keep the connection secure. WPA-Personal is also known as WPA-PSK (refer to Figure 24.2).

Although WPA is a stronger encryption standard than WEP, there are several potential weaknesses in the way WPA might be configured by a particular user. These include:

  • Encryption keys that are too short—The longer the encryption key, the more secure the network will be. Network experts recommend an encryption key of at least 20 characters.
  • Plain-text encryption keys—A key such as "The quick brown fox jumps over the" is certainly longer than the 20-character minimum recommended, but because it is comprised of recognizable words, it would be relatively easy to crack. Instead, use mixed, random alphanumeric keys. For example, a key such as "2F1ACB67EF90O F77A" would be much harder to crack because there are no recognizable words in it.

To see for yourself the threat that short, plain-text encryption keys pose to your WPA-based wireless network, you can download the WPA Cracker utility from tinyPEAP (http://www.tinypeap.com). The network packets WPA Cracker needs for analysis can be gathered with the Ethereal open-source network protocol analyzer available from http://www.ethereal.com. As suggested earlier in this chapter, you should use WPA Cracker and similar tools to analyze your current WPA-based network configuration for vulnerabilities.

To protect yourself against WPA hacking on your home or small-office network, use WPA encryption with a long, random alphanumeric encryption key.

For larger, corporate networks, a more powerful version of WPA known as WPA-Enterprise can be used. WPA-Enterprise (also known as WPA-RADIUS) differs from WPA-Personal in these ways:

  • A RADIUS or AAA server is used to authenticate individual users
  • Authentication uses the IEEE 802.1X standard developed in 2001
  • WPA supports the Extensible Authentication Protocol (EAP)

Regardless of the version of WPA you might select, your wireless access points and network clients must be configured to use the same settings to make a connection possible, just as with the older WEP security standard.

Figure 24.1 shows a typical router being configured to use WPA encryption, and Figure 24.2 shows a matching configuration for a network client running Windows XP.

Figure 1

Figure 24.1 This router is configured to use WPA-Personal encryption.

1. Selects other security settings.

2. Selects security algorithm

3. Shared key; note the mixed alphanumeric text used

4. Specifies time between changes to the original key

5. Saves settings

6. Other security settings available.

7. Opens help screen

Figure 2

Figure 24.2 Configuring a Windows XP client to use WPA-Personal encryption.

1. SSID (wireless network name)

2. Selects network security setting (WPA-PSK = WPA-Personal)

3. Selects encryption type; TKIP is the default for WPA

4. Pre-shared network key (Windows conceals the actual characters for security)

Moving to WPA2 (IEEE 802.11i)

Although WPA, particularly in its WPA-Enterprise version, is much more secure than WEP, it is not as secure as it could be. As mentioned previously in this chapter, WPA was designed as an interim solution until the ratification of the IEEE 802.11i standard could take place. IEEE 802.11i was ratified in 2004, and the first products became available in the fall of 2004. IEEE 802.11i is the basis for WPA2, and WPA2 is the term used to identify IEEE 802.11-based products which meet IEEE 802.11i security standards. WPA2 differs from WPA in the use of a stronger encryption algorithm. While WEP and WPA used RC4 encryption, WPA2 uses the stronger AES encryption algorithm.

To upgrade existing WPA-compatible wireless network hardware to use WPA2 security, you might need to perform one or more of the following operations:

  • Download and install updated client device drivers—Note that some client adapters might not support WPA2 security because WPA2 security requires more intensive computation than WPA.
  • Download and install updated router and wireless access point firmware—Note that some wireless routes or WAPs might not support WPA2 security because WPA2 security requires more intensive computation than WPA.

Note that some vendors don't explicitly state that their products support WPA2. Instead, they might list the security features the adapters support. Table 24.1 cross-references security features to WPA/WPA2 security standards supported.

Table 24.1 Wireless Security Features/Security Standards Cross-Reference

Security Feature

Equivalent Wi-Fi Security Standard

WEP

WEP

TKIP

WPA-Personal

802.1x

WPA-Enterprise

AES

WPA2 (Personal/Enterprise)

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020