The present invention provides a document verification system capable of verifying
whether a document is an original at low cost and with ease. A terminal device
acquires, as a registered feature vector feature information indicating a feature
of a nonreproducible disorder portion in a printing region on a document serving
as the original, and stores the registered feature vector on a hard disk via the
Internet. A server acquires, as a calculated feature vector the same information
as the registered feature vector in a document to be verified as to whether the
document is the original, reads out the registered feature vector from the hard
disk, compares the acquired calculated feature vector with the read out registered
feature vector, and verifies whether the document to be verified is the original
on the basis of a result of the comparison.