A method of embedding an optical signature in a document and document
produced therefrom. The optical signature is an optical pattern generated
from a known value, such as a mathematical, geometric, trigonometric,
size, phase, and the like, and the same value can be generated from
examination of a document having the embedded optical pattern. The
document can be validated, authenticated, or the determination of a valid
copy of an original document with the embedded optical signature made
through comparison of the known value and the value generated from the
optical pattern on the document. The optical pattern can also be
generated from other identification codes on the document.