8. The computer-implemented method of claim 5 , further comprising: generating a second signature for a different version of the first document, the first document and the different version of the first document having differing content.
8. The computer-implemented method of claim 5 , further comprising: generating a second signature for a different version of the first document, the first document and the different version of the first document having differing content. 9. The computer-implemented method of claim 8 , wherein the different version of the first document includes modified content of the first document.