IFX Mail Archive: RE: IFX> Some comments by Lexmark on PDF/is

IFX Mail Archive: RE: IFX> Some comments by Lexmark on PDF/is

RE: IFX> Some comments by Lexmark on PDF/is

From: Rick Seeler (rseeler@adobe.com)
Date: Thu Dec 19 2002 - 16:37:12 EST

  • Next message: Buckley, Robert R: "RE: IFX> Some comments by Lexmark on PDF/is"

    The 'Adobe.PPKLite' issue has been dealt with in the 0.5 version of the
    PDF/is specification that I will be releasing shortly.

    Other comments below...

    > -----Original Message-----
    > From: owner-ifx@pwg.org [mailto:owner-ifx@pwg.org] On Behalf
    > Of Buckley, Robert R
    > Sent: Thursday, December 19, 2002 11:54 AM
    > To: ifx@pwg.org
    > Cc: 'don@lexmark.com'
    > Subject: RE: IFX> Some comments by Lexmark on PDF/is
    > Don's comment reminded me of another comment I received this
    > week in connection with the PDF/is review.
    > Rob
    > ==============
    > Acrobat assigns "Adobe.PPKLite" as a fixed handler name for
    > PKI-based signature/encryption by Self-Sign. It means that we
    > have no choice but signature/encryption by Self-Sign, when we
    > use Acrobat. If Self-Sign can deal with certificates issued
    > by CA (Certificate Authority), third vendors which have CAs
    > will be freed from the burden of offering their plug-ins.
    > However, at the same time, they won't be able to expand their
    > unique business by their plug-ins. The preference is to make handler
    > names user definable; a handle name such as "Adobe.PPKLite"
    > should be a default, not fixed.
    > In addition, file format exchange is not easy when
    > signatured/encrypted in PKI-base.

    Yes, doing PPK encryption does require more code -- you need a mechanism to
    retrieve the consumer's public key. That will be added to the IPPFAX spec.

    > Private Keys are required for re-signature and decryption.
    > Another problem is whether
    > automatic re-signature is acceptable or not.

    Why do we need automatic re-signaturing? Who is going to be modifying the
    file? Re-signaturing has the same burden as signaturing in the first place.
    In any case, PDF/is does not allow for modification of the file once created
    (PDF Incremental Updates [pdf] Section 3.4.5 are not allowed). if you wish
    to make modifications, a new PDF/is file must be created. This would assume
    someone was using this file on a PC or some other non-streaming device.

    > -----Original Message-----
    > From: don@lexmark.com [mailto:don@lexmark.com]
    > Sent: Thursday, December 19, 2002 1:21 PM
    > To: ifx@pwg.org
    > Subject: IFX> Some comments by Lexmark on PDF/is
    > All:
    > This is not an exhaustive list of Lexmark's comments but are
    > a group dealing with intellectual property.
    > 1) Do we have a patent letter of assurance from IBM and any
    > other holders of IP on JBIG2?
    > 2) What is Adobe's position on PPK-Lite? Are there patents?
    > Are they licensed RF?
    > 3) Are there any other known IP issues with Digital
    > Signatures? If so, should they be noted?
    > **********************************************
    > Don Wright don@lexmark.com
    > Member, IEEE SA Standards Board
    > PatCom Chair, SCC Liaison
    > Member, IEEE-ISTO Board of Directors
    > f.wright@ieee.org / f.wright@computer.org
    > Director, Alliances & Standards
    > Lexmark International
    > 740 New Circle Rd
    > Lexington, Ky 40550
    > 859-825-4808 (phone) 603-963-8352 (fax)
    > **********************************************

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