Browse Prior Art Database

Key Management for Super-Distributed Documents

IP.com Disclosure Number: IPCOM000117630D
Original Publication Date: 1996-Apr-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 148K

Publishing Venue

IBM

Related People

Chow, CS: AUTHOR [+2]

Abstract

Super-distribution is a method for distributing and managing digital documents. In this method, documents are encrypted. The encrypted documents are widely and freely distributed. Content providers control the release of documents' contents by controlling the release of their decryption keys, which are orders of magnitude smaller than the documents. Super-distribution separates the managing of document contents from document distribution and reduces the former to management of keys. Disclosed is a practical and efficient method for managing the decryption keys of super-distributed documents. The method allows a key to be issued to unlock a set of documents (e.g., all twenty six volumes of an encyclopedia) or a key to unlock some number of issues of a subscription (e.g., six issues of a monthly magazine).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 37% of the total text.

Key Management for Super-Distributed Documents

      Super-distribution is a method for distributing and managing
digital documents.  In this method, documents are encrypted.  The
encrypted documents are widely and freely distributed.  Content
providers control the release of documents' contents by controlling
the release of their decryption keys, which are orders of magnitude
smaller than the documents.  Super-distribution separates the
managing of document contents from document distribution and reduces
the former  to management of keys.  Disclosed is a practical and
efficient method for managing the decryption keys of
super-distributed documents.  The method allows a key to be issued to
unlock a set of documents (e.g., all  twenty six volumes of an
encyclopedia) or a key to unlock some number of  issues of a
subscription (e.g., six issues of a monthly magazine). Moreover, the
method does not require the management of a large key database.

      More and more contents are (and will) be produced and consumed
in digital forms, without ever involving any printing process.  This
is because digital documents have a number of advantages over paper
or other traditional forms of documents.  For example, digital
documents are easy to distribute, modify, and duplicate.  Moreover,
they allow new ways of document distribution and management, not
practical for physical documents.

      Super-distribution is a way of distributing and managing
digital documents.  See (1)  for an introduction to
super-distribution. The basic idea is that documents are freely
distributed through any channels (including insecure ones) and made
widely available (on any servers), but the documents are all
encrypted, each using a different key.

      Content providers control the release of document contents by
controlling the release of the decryption key.  Decryption keys are
easier to manage as they are orders of magnitude smaller than the
documents they decrypt.  Because of their reduced size, they may be
sent to a use using a speedy but bandwidth-limited channel.

      Super-distribution separates the problem of managing document
contents from the the problem of document distribution, and further
reduces the former to the problem of key management.  However, many
important an practical issues related to the problem of key
management must be addressed.

      This disclosure addresses many issues related to the key
management problem of super-distribution.  The solution does not
require the maintenance of a huge key database, e.g., one that grows
with the number of documents.

      For each encrypted document, a client has to request a
decryption key from the server.  However, the disclosure also allows
a single key to be issued to unlock a collection of documents (e.g.,
a master key to unlock all 26 volumes of an encyclopedia).
Furthermore, the server can also issue a key to unlock a series of
yet-to-be published  docum...