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What is Wi-Fi Protected Access?
Wi-Fi Protected Access (WPA) is a specification of standards-based,
interoperable security enhancements that strongly increase the
level of data protection (encryption) and access control (authentication)
for existing and future wireless LAN systems. WPA is derived from
and will be forward-compatible with the forthcoming IEEE 802.11i
draft standard. It fixes all known weaknesses of Wired Equivalent
Privacy (WEP), the original security mechanism introduced with
the 802.11 standard. The technical components of WPA include Extensible
Authentication Protocol (EAP), Temporal Key Integrity Protocol
(TKIP), Message Integrity Check (MIC), and 802.1X for authentication
and dynamic key exchange.
What does WPA mean to customers?
WPA provides Wi-Fi wireless LAN users with a high level of assurance
that their data will remain safe and protected and that only authorized
users can access the network. WPA is especially attractive for
enterprise customers, satisfying the demanding security needs
of large business networks. We expect that the availability of
WPA-enabled products will increase enterprise adoption of Wi-Fi
wireless LANs, and the majority of existing customers will upgrade
their wireless infrastructure to support WPA as a standards-based
solution.
How does WPA work?
In the WPA-enabled network, the client (notebook) first associates
with the access point. The access point blocks LAN access until
the user can be authenticated. If the client proves credentials
to the authentication server, the client is allowed to join the
LAN. If not, the client stays blocked from joining the LAN. Once
the client joins the LAN, the authentication server distributes
a TKIP encryption key to both the client and the access point.
The client can then begin communicating on the LAN, encrypting
data back and forth with the access point.
Will WPA work for home and small business users?
Yes. Wi-Fi Protected Access has a special mode designed for home
and small business users who do not have access to network authentication
servers. In this mode, known as Pre-Shared Key, the user manually
enters the starting password in their access point or gateway,
as well as in each PC on the wireless network. Wi-Fi Protected
Access takes over automatically from that point, keeping unauthorized
users that don't have the matching password from joining the network,
while encrypting the data traveling between authorized devices.
What are the hardware and software requirements for
enterprise?
The hardware requirements for enterprise include an authentication
server (RADIUS server), WPA-enabled access point, and a WPA-enabled
client. Once WPA is enabled, all clients and access points on
the network must be WPA-enabled in order to access the network.
Software requirements include a strong EAP type such as TLS,
TTLS, or PEAP running on the RADIUS server. The access point must
run TKIP and 802.1X. The client must run TKIP, 802.1X, and an
EAP supplicant with the authentication protocol that matches the
RADIUS server.
What is 802.11i?
802.11i is the IEEE draft specification for wireless LAN security,
and is not yet finalized. The components of 802.11i are essentially
WPA, plus Advanced Encryption Standard (AES).
How does WPA impact network performance?
Internal Broadcom benchmarks have demonstrated the same high performance
data throughput with or without WPA enabled.
Why does Broadcom's solution have hardware-based AES
when AES is not yet required for WPA?
In addition to WPA, AES encryption will be a key component in
the forthcoming 802.11i security specification. Broadcom has enabled
AES in hardware, which significantly improves performance over
software implementations of AES.
How does WPA compare to Wired Equivalent Privacy (WEP)?
WEP was fundamentally flawed, and eventually cracked by scientists
and hackers. WPA fixes the flaws of WEP.
WEP WPA
| |
WEP |
WPA |
| Encryption |
40-bit keys |
128-bit keys |
| |
Static Key: same key used by everyone on the network |
Dynamic session keys. Per-user, per-session and per-packet
keys |
| |
Manual Distribution of keys — hand-typed into each
device |
Automatic distribution of keys |
| Authentication |
Flawed; uses WEP key itself for authentication |
Strong user authentication, utilizing 802.1X and EAP |
What does it mean for Broadcom's products to be certified
for Wi-Fi Protected Access?
The Wi-Fi Alliance, which conducts rigorous interoperability tests
on Wi-Fi products, is now testing devices for WPA certification.
This guarantees seamless operation among Wi-Fi products from different
vendors implementing WPA security. Broadcom products were chosen
by the Wi-Fi Alliance to be used in the standard test bed, and
will be used as the yardstick that all other products are measured
against for interoperability. As one of the first vendors to be
certified for WPA, Broadcom is enabling its customers to quickly
deliver products enabled with WPA.
Which Broadcom products are actually WPA CERTIFIED?
The Broadcom 802.11g Access Point Reference Design, BCM94306 GAP
and the Broadcom 802.11g CardBus Reference Design, BCM94306 CB
have been WPA-CERTIFIED.
When will Broadcom ship WPA solutions to its partners?
Broadcom is currently shipping reference designs that are WPA-CERTIFIED
to its partners. Broadcom-based products that are already in the
market may be updated through a software download from the manufacturer's
web site. Check the manufacturer's web site for availability and
instructions.
What is involved in upgrading existing wireless products
to support WPA?
WPA was designed to run on existing wireless access points and
client devices with a software upgrade. In addition to upgrading
their network interface card, PC users will also need to upgrade
their client with software called a "supplicant." With
the help of Broadcom, Microsoft developed a supplicant for Windows
XP users. Broadcom is working to develop supplicants for Windows
2000, Windows 98 and other operating systems.
Which wireless LAN vendors are using 54g™ chipsets?
Broadcom's 54g™ customer list continues to grow as consumers
and enterprises demand high performance products. Broadcom supplies
the industry's leading wireless LAN system vendors, including
Linksys, Belkin and Buffalo/MELCO.
Broadcom is also seeing tremendous up-take for 54g™ from
notebook PC manufacturers. In addition to our ongoing relationship
with Apple, we recently announced that Dell is providing two configuration
options in its new Latitude D line, 54g™ and dual-band 802.11a/g,
and HP has adopted 54g™ for its new Compaq Presario 2100
and 2500 series notebooks. Several other PC manufacturers are
lined up to announce in the coming months.
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