1. A document verification system for verifying whether a document is an original, the system comprising: an information storage device; an information registration device including a registration information acquisition component for acquiring, as registration information, at least one of feature information, indicating a feature of a nonreproducible disorder portion in a printing region on a document serving as an original, and state information, indicating at least one of a surface state and a thickness-expressing spots state, in a non-printing region on the document and a storage processing component for storing the registration information acquired by the registration information acquisition component in the information storage device; and a document verification device including an verification information acquisition component, for acquiring, as ascertainment information, information corresponding to the registration information in the document to be verified, a readout component for reading out the registration information from the information storage device, and an verification component for comparing the verification information acquired by the verification information acquisition component with the registration information read out by the readout component and verifying whether the document to be verified is the original on the basis of a result of the comparison.