A center configured to communicate with an OTA master configured to control software update for an electronic control unit mounted on a vehicle includes one or more processors. The one or more processors are configured to store security information in which regions are associated with security levels required for the software update, receive, from the vehicle, position information indicating a position of the vehicle, and generate a distribution package applied encryption at a security level associated with the region where the vehicle is located based on the security information and the position information.