Robust Security Network

Robust Security Network (RSN) is an element in 802.11i. RSN dynamically negotiates the authentication and encryption algorithms to be used for communications between WAPs and wireless clients. This means that as new threats are discovered, new algorithms can be added.

RSN uses the Advanced Encryption Standard (AES), along with 802.1x and EAP. The security protocol that RSN builds on AES is called the Counter Mode CBC MAC Protocol (CCMP). AES supports key lengths up to 256 bits, but is not compatible with older hardware. However, there is a design to allow RSN and WEP to coexist on the same wireless LAN; it’s called Transitional Security Network or TSN. It’s important to note, however, that a WLAN on which some devices are still using WEP is not optimally secured.