8. The method of claim 6 , wherein the data is employed to verify that the tangible version of the document has not been altered since the seal was applied.
9. The method of claim 8 , wherein: the data includes a hash of information in the document; and verifying that the tangible version of the document has not been altered since the seal was applied includes: determining a current hash of the information in the document; and comparing the current hash to the hash encoded in the seal.