36. The content server of claim 35 wherein the means for calculating the document identifier comprises: a first one-way hashing mechanism that is responsive to the text string for generating a hashed text string; a second one-way hashing mechanism that is responsive to the encrypted document content for generating hashed document content; and a third one-way hashing mechanism that is responsive to the hashed text string and the hashed document content for generating the document identifier.
35. The content server of claim 31 wherein the publishing tool comprises means for calculating a document identifier for each encrypted document from the encrypted document content and a text string embedded in the publishing tool code.