All system elements are 3G and thus capable of handling the related security mechanisms. 3G AKA is executed and 3G security context established. The USIM receives parameters RAND and AUTN and responds with RES, CK and IK.
NOTE: If service no. 27 is active in the USIM (to support mixed 2G/3G scenarios), Kc is generated by conversion function c3 and additionally included in the response. However, Kc is not needed in this security scenario and can be discarded by the ME.