WPA2 replaced WPA, and implements the mandatory elements of 802.11i. In particular, it introduces a new AES-based algorithm, CCMP, which is considered fully secure. WPA2 certification is mandatory for all new devices that bear the Wi-Fi trademark. For WPA- and WPA2-Enterprise, the Wi-Fi alliance recognizes EAP (Extensible Authentication Protocol) types to its certification programs for WPA- and WPA2- Enterprise certification programs. This was to ensure that WPA-Enterprise certified products can interoperate with one another. Previously, only EAP-TLS (Transport Layer Security) was certified by the Wi-Fi alliance.