A method for key derivation for non-3GPP access. The method includes determining a particular non-3GPP access type, wherein the particular non-3GPP access type is one of N different particular non-3GPP access types (N>1), and each one of the N particular non-3GPP access types is associated with a unique access type distinguisher value. The method also includes generating (s604) a first access network key using a key derivation function and the unique access type distinguisher value with which the determined particular non-3GPP access type is associated, thereby generating a first access network key for the particular non-3GPP access type.