Gallery of Adobe Remedies

A large amount of useful content is now encoded as PDF (Portable Document Format) files, including files marketed for eBook document readers. Unfortunately, some of this content is not usable in all the lawful ways a purchaser desires, due to access control mechanisms created by Adobe and adopted by content publishers to the detriment of their customers. Computer professionals who have examined these mechanisms have found them easy to defeat. This web site will publish information about Adobe's access control mechanisms and the remedies people have devised to deal with them.

PDF Password Recovery Tools

Here are directories of links for removing PDF security and PDF password tools. You can, for example, purchase Eltima's Recover PDF Password for Mac or Recover PDF Password for PC.

Utility to Remedy fileOpen PDF Encryption

ineptpdf (Google it) is a tool for bypassing fileOpen PDF encryption.

June 2010: new fileOpen circumvention tool available from Tetrachroma: click here for information.

A while back, an anonymous contributor sent the source for fileSaveAs.c a program that "reads a pdf encrypted with the fileOpen plugin, and attempts to write a plain pdf." I have no way to contact the author, but you can send bug reports to me and I'll post them here.

Xpdf and Poppler Remedies

Xpdf is an open-source PDF viewer for Unix, VMS, OS/2, and Windows, available at The documentation of the decryption feature says: "If any security features are turned on by the creator of a PDF document, the PDF file will be encrypted. These security features let an author disallow printing, copying text/graphics, editing, and/or adding annotations."

David E. Smith at has created a patch to Xpdf that disables the security features. The patch (revised July 24, 2001) is available here. Mr. Smith writes: Patch xpdf (the diff is against 0.92 but should be easily adaptable to future version) and feed '--enable-antikick' to 'configure'. The patch is bigger than it should be; all but the bottom twenty lines or so are diffs to the 'configure' script itself. The name 'antikick' came from Harlan Ellison's 'Kick Net Piracy' campaign, btw. Ironically, I fully support him in this...

Hans Nieuwenhuis has contributed an Xpdf patch for version 0,93, also available at . See his web page on the patch for more information. (Older 0,92 version here and here.) Mr. Nieuwenhuis writes that the difference between Mr. Smith's patch and his are that his does not disable printing protection, it only re-enables copy and paste. FreeBSD incorporates this patch into their xpdf port.

An anonymous correspondent has sent generic Xpdf patch instructions that work in versions 0.92 and 0.93 and should be easily adaptable to all future versions, and another anonymous reader sent in a patch file for xpdf 3.00. Yet another anonymous correspondent had a comment about printing protection.

Erik Hovland contributed this patch for XPDF version 3.02p12.

Poppler is a PDF rendering library based on the Xpdf 3.0 code base. Eriv Hovland has this patch for poppler release 0.6.4.

Ghostscript is a Remedy

A helpful reader wrote in to remind me that: "GhostScript/GhostView ... handle PDF just fine and have been completely bypassing its restriction schemes for quite some time without much fanfare. There are precompiled versions for most popular OSes, donwloadable from many places.

The home page for Ghostscript is

The sourceforge project page for Ghostscript is

Also see the GNU Ghostscript page.

Geoffrey Keating's Encrypted PDFs page offers appropriate patches to Ghostcript for reading encrypted PDF files. For versions 4.01 and higher, use

Kyler Laird's PDF utilities build on Geoffrey Keating's work. Laird offers a web form you can use to convert PDF files to Postscript, and a hack for turning on printing for encrypted PDF files. Thanks to reader Rashkae, who adds: "You can then do a pdf2ps and back again with ps2pdf to generate a clean, unencrypted, printable, PDF file."

Rusty Mase, a professional cryptanalyst, challenged Kyler Laird to crack a sample PDF file he supplied. To Mase's surprise, Laird did it. See if you can do it too.

An anonymous contributor tells how to Convert a printable Adobe eBook to an unprotected PDF file by following these simple steps.

Older version of MacOS X PDF Viewer is a Remedy

Marc Hoffman announced (see March 3, 2002 entry) that the document previewer bundled with Mac OS X allows one to strip the security features from a PDF automatically simply by printing the document to a Postscript file and redistilling it. Read his report, Disabling Security Settings in Acrobat Files. The claim in the report that password protection will prevent PDF unlocking turns out to be untrue; the version of the document provided here, by a third party, has the password removed. The document is posted with Mr. Hoffman's permission.

Another correspondent wrote in January 2006 that she didn't even need to save the document as a Postscript file; it sufficed to "print" it as a PDF under a different name.

But in February 2006, someone informed me that Preview Version 3.0.4 (398) under Mac OSX 10.4.5 does not permit these operations on password-protected PDF files.

Adobe Acrobat Access Plug-in is a Remedy

An anonymous informant writes: The Adobe Acrobat Access Plug-in 4.05 enables vision-impaired users to read Adobe PDF documents in Acrobat 4.0x or Acrobat Reader 4.0x.

The Access plug-in supplements the standard Acrobat and Reader display of PDF documents with an alternative view that supports screen-reading applications for Microsoft Windows 95, Windows 98, and Windows NT. This view presents the textual content of a PDF file in a separate window. The window contains the text in an approximated reading order. Standard Acrobat features, such as hypertext links, notes, bookmarks, sounds, and movies, are available in the Access view.

Once this is installed, press control + 4 to move to "TEXT" mode. This mode enables you to copy it to a text2speech program ... or wherever you want. I've tested it in Acrobat 4 and it works. You then press Control + e to move back to the standard viewing mode.

eBooks Purchased from

An anonymous source has provided instructions for removing security from Amazon-purchased eBooks. This requires Acrobat 6; Acrobat 7 reportedly does not work.

Another anonymous source writes: "I tried using Scansoft PDF creator to print to a PDF file. I then found I could read the printed PDF file in other machines."

Information About PDF

Planet PDF

PDF 1.3 Encryption Explained, by Anonymous. Also see the official Adobe spec., a Perl script to decrypt PDF files, by Anonymous.

Google search for "Adobe password recovery"

isilo eBook format

Here is the decrypter for isilo format, written by "klemm". It's currently incomplete: it only works on the first isilo format, not the newer/current format . This decrypter is however successfuly used by the opie-reader ebook reader. desilo.h, desilo.c.

Microsoft's .LIT Format contains information about removing protections from eBooks encoded in the Microsoft .LIT format. Source code is mirrored here.

Information About eBooks

Planet eBook

Putting A Lock On E-Books, article (July 19, 2001) by Siva Vaidhyanathan.

Call for Technical Submissions

I am interested in receiving and publishing the following kinds of information: Mail submissions to Dave Touretzky. Anonymous submissions are fine.

Note: this web site is for discussion of purely technical information of interest to computer scientists and lawful content users. I am not interested in receiving rants about Adobe or the DMCA. Go to the Boycott Adobe site for that. RTMPE.txt file In 2009 Adobe used a DMCA takedown notice to SourceForge to suppress an open source implementation of a network protocol called RTMP. Here is the technical specification and the source code. More info is available here.

Code As Speech

For more on the issue of computer code as protected speech, visit the Gallery of CSS Descramblers.

Old Stuff: The ElcomSoft Controversy
The current technology leader in Adobe remedies is a Russian company called ElcomSoft. Unfortunately their best-known programmer, Bauman Moscow State Technical University computer science Ph.D. student Dmitri Sklyarov, was held in the US for several months in 2001, pending prosecution under the Digital Millennium Copyright Act, and is no longer speaking publicly about these issues.

ElcomSoft has announced a new PDF password recovery tool. Details available at their web site and this article in Wired.

Defcon 9 (2001) presentation by Dmitri Sklyarov, "eBooks security - theory and practice", in HTML/GIF format, raw text format (no graphics), or PowerPoint original.

Summary of Sklyarov's results, by Bruce Perens.

Cryptome mirror of ElcomSoft's AEBPR (Advanced E-Book Processor) software version 2.2, which decrypts 25% of an E-book as a demonstration. Note: ElcomSoft is no longer distributing this software.

And Justice for Adobe, an article by Lisa Rein at O'Reilly Network Weblogs, nicely summarizes the case through July 2001.

Anonymous sources have confirmed that adding the following entry to the Windows registry will unlock the software so that it will decrypt 100% of a document: [HKEY_LOCAL_MACHINE\Software\Elcom\Advanced eBook Processor\Registration] "Code"="LEPR-T2K7-NA8Z-3DUE-EVDQS-TMPV-MBAUB".

From someone who has personally verified that this works: "Using this program I was able to convert a locked Adobe eBook to PDF format. I then purchased an ebook from Barnes&Noble only because I had a copy of AEBPR. I will not distribute copies of the unlocked PDF file, but I would not have purchased an ebook in the Adobe format when it is locked to an operating system on a single computer."

Problem report: "I downloaded the free trial version of AEBPR, then edited the registry as indicated in your "Adobe Remedies" site, and it worked beautifully on the free ebooks I had downloaded previously (using Adobe ebook Reader 2.1). I then bought an ebook; however, it was necessary to update to Adobe ebook reader 2.2. Unfortunately, the attempt to decrypt the new ebook resulted in the error, "Bad data in the son.dat. Error 2." Then, "No EBX books available."

AEBPR son.dat Problem

Adobe has disabled the earlier version 2.2 of their eBook reader, so that it can no longer be installed on new machines. Their certification server does not give a certificate for this version anymore. According to an anonymous reader, a solution to the problem is as follows:
  1. Find someone who already has version 2.2 build 200 installed and activated.
  2. Ask him to send you all files from his "Data\Vouchers" folder.
  3. Put these files in your Data\Vouchers folder, overwriting your own ones.
  4. Run the Reader. It will show the following message:
    Voucher Update Required
    You will not be able to read your eBooks until you update your
    installation of Acrobat eBook Reader. Please contact Adobe Systems
    Customer Support at
    for assistance in completing this update.
    Challenge: [...]
  5. Call Adobe, give them the Challenge, and receive an activation code.
  6. Enter that code into the Reader -- it will updated. Now you can purchase the books from that version, and use AEBPR to convert them to PDF.
I don't have these Data\Vouchers files, and I don't know anyone who does, so please don't email me asking how to obtain them. -- Dave Touretzky

The old fix to the son.dat problem, sent in by an anonymous reader, was as follows: "Don't use the current version of eBookReaderInstall.exe (size: 10,621,400 bytes or 10372 KB.) Instead use the earlier version (also named 2.2 build 200!) which has a size of 10,582,776 bytes (or 10334 KB). You can find a copy of the earlier version at: If you already have installed the later version of this program, you'll have to uninstall it and remove the DATA folder before installing the earlier version. Then verify your installation with a free e-book from" This no longer works, since Adobe changed their certification server to block it.

Bryan Guignard's whitepaper on PDF Security "explains what the ElcomSoft tools can and cannot do, and takes a brief look at the PDF specification to uncover the fundamental flaw in PDF security." Also available in Postscript.

"Boycott Adobe" graphic from the now defunct web site.

US v. Sklyarov FAQ from the Electronic Frontier Foundation ( will answer all your questions.

Planet eBook's page on the Adobe/Elcomsoft/Sklyarov controversy offers the most comprehensive coverage of the case.

Legal Disclaimer: "Adobe" is a registered trademark of Adobe Systems, Inc..

Dave Touretzky
Last modified: Tue Apr 12 02:59:30 EDT 2011