Subject: new patent app conflicts with pgp

From: John Kane <[email-masked]>
Date: Sat, 05 Jan 2002 13:53:09 -0500

Someone has applied for a US patent on the technique of
using a symmetric session key on a document, and then using
multiple public keys to encrypt the session key to multiple
recipients.  Newton Hammet newton(at)hammet.net brought
this to our attention.

  http://appft1.uspto.gov/netahtml/PTO/srchnum.html
  (search for 20010055396)
http://lists.gnupg.org/pipermail/gnupg-users/2002-January/011444.html
http://lists.gnupg.org/pipermail/gnupg-users/2002-January/011445.html

He cites RSA as prior art, but not RFC1991/RFC2440.
This seems to be in the context of a business model where
a server allows secure access to a symmetrically-encrypted
document by allowing the author to upload multiple
public-key headers for multiple recipients, and to repost
both amended PKI access lists and amended updates of
the document (potentially re-using the orig.sess key).

However:
  [0024] As another example, encrypted decryption keys could
  be bundled into the message and the single message with the
  encrypted decryption keys could be broadcast to all recipients
  without compromising the security of the mechanism.

--
John Kane
Stratham, NH (USA)

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From: Marcel Waldvogel <[email-masked]>
Date: Mon, 07 Jan 2002 22:22:51 +0100

John,

It seems to me that PGP is clear prior art in itself to the relevant 
claims, so I don't think we should need to worry.

-Marcel

---

From: David Shaw <[email-masked]>
Date: Mon, 7 Jan 2002 17:56:29 -0500

> He cites RSA as prior art, but not RFC1991/RFC2440.

I've not read the patent, but if there really is a prior art conflict
with PGP:

http://www.uspto.gov/web/menu/helpfaq.htm#a50

  #50 How does one file protest on patents that are pending? 

  Protests by a member of the public against pending applications will
  be referred to the examiner having charge of the subject matter
  involved. A protest specifically identifying the application to
  which the protest is directed will be entered in the application file
  if: (1) The protest is submitted prior to the publication of the
  application or the mailing of a notice of allowance under rule
  1.311, whichever occurs first; and (2) The protest is either served
  upon the applicant in accordance with rule 1.248, or filed with the
  Office in duplicate in the event service is not possible.  For more
  detailed information on protesting a patent, you may visit our Web
  site at http://www.uspto.gov/web/offices/pac/mpep/mpep.htm for the
  Manual of Patent Examining Procedure (MPEP) Chapter 1900.

The specific document referred to is at
http://www.uspto.gov/web/offices/pac/mpep/mpep_e8_1900.pdf

David

-- 
   David Shaw  |  [email-masked]  |  WWW http://www.jabberwocky.com/
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