A security information update system includes a service providing server and information processing devices, the service providing server including: an authentication information memory that stores a pair of security information and identification information; and a service providing unit that provides a service to the information processing device, and the information processing devices including: a policy acquisition unit that acquires a security policy; a security information memory that stores security information; a process executing unit that transmits a pair of the same identification information and security information to the service providing server and receives a service; an authentication information acquisition unit that acquires security information after update; an update unit that updates security information with the acquired security information after the update date and time; and a prohibition unit that prohibits execution of a process of receiving a service after the update date and time until update with the security information.