A computing device of a dispersed storage network includes a processing module operable to receive a plurality of requests regarding writing a plurality of data objects to storage units from a plurality of user computing devices. The processing module is further operable to activate a verification process to verify a content format verification code provided by a user computing device for a request regarding writing a data object, activate a signature process to sign the content format verification code with a trusted certificate to produce a signed content format verification code, send the trusted certificate and a signed content format verification code identification to a dispersed storage (DS) processing unit, receive a verification message indicating that the content format verification code identifies a correct format for the data object, and send the data object in the correct format to the DS processing unit for dispersed storage error encoding and storage.