Method and apparatus for the creation of a self-authenticating document

Method of producing a printed document for self-authentication containing text having the capability that the entire content of the text can be authenticated by reference to the printed document, the method comprising: (i) providing electronic text which is intended to be contained within the document; (Ii) generating a verification value electronic text, representative of the entire contents of said electronic text; (Iii) generate one or more error correction codes to said electronic text; and (iv) generating a machine-readable symbol, representative of said text verification value and the code or error correction codes; wherein the machine-readable symbol is adapted for incorporation within the document when it is printed.