I'm confused by what Ms. Reid has said. On one hand she says that Acrobat 5
allows authors to make separate choices about a PDF document's ability to
be copied and its ability to be read by a screen reader. She then says
"...the accessibility interfaces remain a potential path for circumventing
the security mechanisms."
If a future version of Acrobat is engineered so that PDF's are exposed to
only certain, "trusted" screen readers, will an author still have the
choice to protect their document from those screen readers because they
still represent a potential tool with which to work around the document's
copy protection scheme?
And at what point do the system requirements to run the Acrobat reader -
because of their cost - create a new category of users for whom PDF is
inaccessible? - Jon
-----Original Message-----
From: Kelly Pierce [mailto:[log in to unmask]]
Sent: Wednesday, May 16, 2001 8:45 PM
To: VICUG-L: Visually Impaired Computer Users' Group List
Cc: Steuerwalt, Jon C.
Subject: Adobe Document Security Changes Explained
Even with all the access improvements made with the Acrobat reader, there
is still the security barrier. Documents that do not permit copying may
not be able to be read by a blind user. These include briefs and
decisions on the web site of the U.S. Supreme court. The Supreme Court is
not covered by Section 508. Below, an engineer from Adobe discusses this
issue with an end user.
kelly
>From: George <[log in to unmask]>
>At the risk of starting a major flame throwing thread, I thought this
>response from someone at Acrobat Engineering, Adobe Systems, would be of
>interest to all of you.
>
>It's their final paragraph which makes interesting reading, suggesting
>that whilst documents would be accessible, they might just be tied in
>with trusted screen readers.
>
>George Bell.
>
>
>The issue of security vs accessibility is a thorny one for Acrobat. Let
>me describe where we are today:
>
>1. In Acrobat 4, there is a security bit that controls whether or not
>the
>contents (that is, text and graphics) of a document can be copied. The
>Access plugin for Acrobat 4.05 ignored that permission and always
>presented
>the text of the file for screen readers. We discovered that users (not
>necessarily blind users) were exploiting this to circumvent the document
>protections and copy the content of the file, to the dismay of the
>authors.
>
>2. In Acrobat 5, we added a new protection bit so that authors could
>separately control whether the content could be copied and whether the
>content should be exposed to screen readers. This was to provide
>authors more flexibility . They can control the accessibility of a
>document explicitly, rather than having accessibility be a side effect
>of the decision to control copying. The default value of this setting
>is to make the document accessible.
>
>We believe most authors don't intend to make a document inaccessible
>when they disable content copy. However, the accessibility interfaces
>remain a potential path for circumventing the security mechanisms. So
>authors who are particularly concerned about controlling the content of
>their documents may decide they'd rather publish inaccessible documents
>than risk the possibility that unauthorized users could copy the
>contents.
>But this is the author's decision, and issues with the protection
>settings
>on a document should be taken to the author.
>
>3. Unfortuneately, most of the documents existing in the world today
>were
>created before the new permission existed, so accessibility and content
>copying are still tied together. And because we must honor the requests
>of
>those authors, older protected documents are not accessible in Acrobat
>5.
>
>We need to educate authors about the different security settings, and
>this
>will take time.
>
>We are also exploring whether there are ways we could let "trusted"
>assistive technology programs access these older protected documents.
>However,
>there are a number of technical problems to be solved before we know
>whether that is possible.
>
> Loretta Guarino Reid
> Acrobat Engineering
> Adobe Systems
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