 Step (4) The ciphertext is appended to the unencrypted MAC and CCMP headers. Although the MAC and CCMP headers are transmitted in plaintext, the MIC protects both the data packet and the headers from error or malicious alteration (Step (2) above). The Sections "WEP - Wired Equivalent Privacy Encryption, p. 209", "Wi-Fi Protected Access; WPA, p. 212" and "IEEE 802. 11i and WPA2, p. 219" have described the key technologies that have been developed to enable wireless LANs to achieve a high level of security. However, that security will only be assured if these technologies are supported in turn by the necessary practical measures. The following section turns to these practical security measures. Chapter Eight WLAN Security Measures In order to ensure that all security vulnerabilities are recognised and addressed, every WLAN implementation needs to consider three aspects of security - management, technical and operational. A comprehensive checklist of best practice security measures in these three areas has been published by the US National Institute of Science and Technology (NIST Special Publication 800-48, see Resources the Section "General Information Sources, p. 363"). Management Security Measures Management security measures address issues that need to be considered when designing and implementing a WLAN. Some of the key management security measures recommended as best practice in the NIST checklist are described in Table 8-7. Table 8-7: WLAN Management Security Measures Management security measure Description Develop a security policy for the The security policy provides the foundation for organisation that addresses a secure WLAN and should specify the the use of wireless technology organisation's requirements including access control, password usage, encryption, control of equipment installation and administration, etc. Perform a risk assessment to Understanding the value and the potential understand the value of the consequences of unauthorised access to assets in the organisation the organisation's assets