A management apparatus includes an assignment unit, a receiver, and a storage unit. The assignment unit assigns issuance privilege key information representing privilege to issue document IDs to one or more processing apparatuses. Each of the one or more processing apparatuses is located on one of local networks and is configured to execute a protection process to generate a protected document from a document. The receiver receives from the one or more processing apparatuses document IDs issued for protected documents by the one or more processing apparatuses. The storage unit stores the document IDs received by the receiver. Each of the document IDs includes the issuance privilege key information assigned by the assignment unit to the one or more processing apparatuses, and information indicating identity of a document ID issued by one of the one or more processing apparatuses.