Improved systems and techniques are disclosed for controlling the security states of anti-theft security systems such as product display assemblies using security fobs. The tasks relating to fob authentication are offloaded to a computer system, and these authentications can be based on identifiers for the different security fobs. The interactions between security fobs and product display assemblies can be consistent regardless of the population of authorized security fobs by using a security code that is shared by the security fobs. When attempting to use a security fob to change a security status for a product display assembly, the provision of the code to the subject product display assembly can be predicated on authorization of the subject security fob by the computer system. The computer system can maintain a list of identifiers for authorized security fobs that is easily updated when new security fobs are added to or existing security fobs are de-authorized from the system.