Apparatuses, methods, and systems are disclosed for network security based on routing information. One method includes receiving at a first network device, a security request message from an initial access and mobility management function (AMF), an initial security anchor function (SEAF)), or a combination thereof. The security request message includes information indicating a serving network name (SNN), whether routing information is required, a subscription permanent identifier (SUFI), or some combination thereof. The method includes determining, at the first network device, routing information based on the security request message. The method includes transmitting, from the first network device, a security response message to the initial AMF, the initial SEAF, or the combination thereof. The security response message includes the routing information.