The 802.11 option
Another standard – IEEE 802.11 (Wi-Fi) – includes a low power version known as Wi-Fi Direct that’s increasingly being integrated into smartphones. Wi-Fi Direct provides a version of Wi-Fi Protected Setup that was created for pairing PC peripherals. Ratified in 2007, Wi-Fi Protected Setup’s value is really to simplify 802.11 security implementations.
Bruce Kraemer, chair of the IEEE 802.11 Working Group, notes that the AES encryption is invariably part of the standard’s security implementations. Wi-Fi Protected Setup addresses only the critical part of pairing devices.
There are two setup options: personal identification number (PIN) and push button configuration (PBC). Routers and other access points (APs) must offer both options, and client devices must at least offer PIN setup. In the first option, the user enters a PIN provided by the manufacturer. In the second, push buttons on the AP and client device(s) to initiate the secure setup. The user is no longer involved in setting a passphrase; the security codes are activated and communicated automatically.
In addition to ensuring that the SSID and WPA2 security key are properly configured, Wi-Fi Protected Setup prevents users who enter incorrect PINs from accessing the network. It also includes a time-out function to cancel the configuration process when identifying credentials are not transferred in a timely fashion.
A balancing act
Ensuring data security is a critical element in any communications scenario and it is particularly important in wireless communication. But in ULP applications security concerns must be balanced against their impact on performance metrics such as battery life. In some instances, the data itself is of little interest to other parties. In others, privacy issues make security a critical concern. Solutions based on both proprietary protocols and international standards offer a range of security options. This enables design teams to provide the right level of security for their products.
This article comes from the Spring 2012 edition of Nordic Semiconductor's ULP Wireless Q
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About the Author
Jack Shandle is a freelance writer specializing in semiconductors, wireless and other high-tech topics. Prior to starting his own business, he worked as editor for Electronic Design and CMP Media