1. A method for verifying matching content between a plurality of text documents implemented with a numerical computation device, comprising: at a first location, forming a first authentication signature from an electronic text character content of a first text document; obtaining a document representation that is a transformation of the first text document, where the document representation represents the electronic text characters converted to a format that is other than electronic text; electronically transmitting the document representation to a second location; electronically storing a second text document derived from the document representation; forming a second authentication signature from an electronic text character content of the stored second text document; and comparing the first and second authentication signatures.