US Patent 7620200 Authentication of identification documents

The presently claimed invention provides apparatus helpful for authenticating or protecting physical and electronic documents like financial documents and identification documents. One claim recites an apparatus including: an authenticator including or utilizing a processor which uses first information in a first portion of data associated with an object as a basis of first authentication information, the first information also being obtainable from a first portion of the object; and an incorporator including or utilizing a processor which incorporates the first authentication information in a second portion of the data, the first authentication information also being obtainable from a second portion of the object. Of course, other claims and combinations are provided as well.