The present invention relates to a public warning system (PWS) in a mobile Communication network, and the present invention relates to a method and an apparatus for resolving a security problem occurring in the PWS with a protocol and actions between other network entities, and managing same. A user equipment (UE), according to the present invention, saves a public key and a public key index pair of a cell broadcast center (CBC), verifies the CBC which has transmitted a digital signature when the digital signature is received from a subject that transmits a public warning, and resolves a security problem related to a public security system so as to receive a message by the public warning system. As a result, according to the present invention, when the public warning message is received in environments such as an evolved universal terrestrial radio access network (EUTRAN), a universal terrestrial radio access network (UTRAN), or a GSM/EDGE radio access network (GERAN), the subject that has sent the public warning message is verified by the user equipment, thereby enabling the user equipment to perform an action appropriate to the warning message in an emergency disaster situation.