current state of FOSS tools for PDF encryption/decryption
After much searching, studying, testing various PDF encryption tools
out in the wild FOSS jungle, these are my findings:
*Password-based cryptography*
encryption with signing: use JSignPDF
encryption w/out signing: use qpdf (not pdftk)
decryption: use qpdf (not pdftk)
viewing RC-4, AES-128: evince, okular, or xpdf
viewing AES-256: impossible
(JSignPDF rationale) It's the only FOSS PDF tool that can both sign
and encrypt. But note that the signature
obviously uses key-based cryptography.
(qpdf rationale) qpdf handles both RC4 and AES, and it supports key
sizes of 40, 128, and 256. It does all the crypto
that pdftk does, plus AES, so there is no benefit to
using pdftk for this.
(viewer rationale) evince, okular, and Xpdf can all view RC4 and
AES-128 encrypted documents. Note that Xpdf is
aesthetically favorable, as it's the only viewer
capable of replacing white backgrounds with a
less harsh color.
(viewer limitations) No FOSS PDF viewer can open AES-256-encrypted
documents at this time. The only option for
non-COTS-using recipients is to downgrade or
remove the encryption (using qpdf) before
viewing. Also note that Xpdf has a -opw option
that's broken (it does not parse the
commandline as documented), but the -upw option
works.
*Key-based cryptography*
key generation: use openssl
encryption with signing: use JSignPDF
encryption w/out signing: impossible
decryption: impossible
viewing: impossible
(rationale) JSignPDF is in fact the only FOSS tool to be capable of
encrypting a PDF using a pkcs12 key and producing output
that is still within the PDF spec (unlike gpg, for
example, which imposes pgp-capability on recipients).
(JSignPDF limitations) JSignPDF is primarily designed as a signing
tool, and it forces signing. It is incapable
of encrypting without signing (as a
workaround, one could do a non-visible sig
with a one-time dummy key and then destroy
the key).
(viewing limitations) The payload cannot be decrypted or viewed
using any FOSS tools. So key-based encrypted
PDFs are useless unless the document recipient
uses something commercial and proprietary to
open the document.
|
0 |
|
Nomen
9/26/2015 4:59:08 PM
comp.text.pdf
5600 articles. 
0 followers.
ramon
0 Replies
1571 Views
Similar Artilces:
PDF PDF PDF
For anyone struggling to figure out how to create a PDF in SWX it's pretty simple but you may have to have the Bluebeam version of swx FIRST go to Tools>Options and check "Save as PDF" Then you can save them right from the save as dialog. Maybe I'm the only dumbass that could't figure that out! ;0) But it was in help under "PDF" An easier way is to download a program from www.pdf995.com that "prints" you files to a PDF foramat. This program works with SW and any other program you use to print with. "3d" <jmiller at marvelindustri...
Postscript to PDF with pdf-tools, pdf-writer, or other
Does anyone have a way to convert Postscript to PDF using pdf-tools, pdf-writer, or other method? Any suggestions? On 14/04/2008, Sean Nakasone <seannakasone@yahoo.com> wrote: > Does anyone have a way to convert Postscript to PDF using pdf-tools, > pdf-writer, or other method? Any suggestions? ps2pdf is standard on any install of Ghostscript, at least on most flavours of Linux/BSD Farrel ...
PDF TO PDF/A
Hello, is it possible to convert a PDF file to PDFA file ? i tried the -dPDFA option and i vefy my pdf file with PDF longlife. I have an error. Thanks for help. ...
pdf \ text (get rid of text in pdf)
Is there a way to remove all text from PDF? Will extract images work for you? If so, PDF-Tools by Tracker Software will do it. http://www.docu-track.com/ -- Don Vancouver, USA "MarosV" <maros.vranec@gmail.com> wrote in message news:ebb897e1-c8e3-4b3a-9274-dfd9d2c845c3@c4g2000hsg.googlegroups.com... > Is there a way to remove all text from PDF? ...
ANN: Fly Text to PDF
Hi All: Fly Text to PDF 1.3 is powerful tool which can convert your text files into PDF. This tool is powerful converter tool running on Microsoft Windows Operating System. You can use this tool to convert your text report, text documents and other text files into PDF quickly and easily. You also can set the PDF properties in each text files by using special tags, or set the default properties for every output PDF files. Please visit our website for more information: http://www.medafan.com/pdf-tools For the output sample, please click on: http://www.medafan.com/pdf-tools/license.pdf Key fea...
Convert PDF image to PDF text
Hi, I have a PDF file with image text documents. hence I can't search the text. How can I convert it to searchable PDF file? Thanx You will have to scan it using an OCR (Optical Character Recognition) application and then create a PDF file. -- Don Vancouver, USA <WhiteLen@gmail.com> wrote in message news:1193737890.691267.165820@z9g2000hsf.googlegroups.com... > Hi, > > I have a PDF file with image text documents. hence I can't search the > text. How can I convert it to searchable PDF file? > > Thanx > Any recommendation for OCR application? ...
convert PDF images to PDF text (OCR)
Hi, I have a book which was entirely scanned into a PDF, there are approximately 300 pages. The problem is that each page is an image of the paper page, not selectable text. How can I convert this PDF made of images to a text-selectable PDF? Or directly convert it to Word? I suppose I'll need some form of OCR. Thanks in advance, Raphael Yes, since you have an image, you need to OCR it into data. You will not have much luck with any formating info, but most OCR programs today to a pretty good job if the image is fairly clean . Larry T. larrynospam@nospamjbmsystems.com wrote in message...
scanned image pdf to searchable text pdf
We have a lot of pdf files that are just scanned images of documents. How easy is it to change these into pdf's that we can search for specific words. I believe Adobe Acrobat Capture will do this when the document is originally scanned, but can it use pdf's that have already been created. If it can, can this process be automated to convert 100s of pdf files? Are there other alternatives to Adobe Acrobat Capture as it is not cheap for a large number of documents? I am new to this, so please keep it simple. Thanks for any help. Adrian HI, As you indicated, your pdf's are ...
Encapsulated PDF Storage and Encrypted PDF file
Hi there, There is no such DICOM attribute as 'Encrypted PDF' ? This attribute would be used to identify whether the DICOM file encapsulate an encrypted PDF file or not... Just a random thought, -Mathieu ...
Embedding PDF into PDF ?
I have read from websearching that it is possible to embed a smaller PDF into a main PDF, but cannot find out how this is done. Would I have to open the PDF as a text file and have my program locate a certain PDF command, then literally just stream the raw smaller PDF into it ? Any links or info would be very much aprpeciated Thanks Paul On Wed, 14 Jul 2004, Paul Champan wrote: > I have read from websearching that it is possible to embed a smaller PDF > into a main PDF, but cannot find out how this is done. Do you want to merge 2 pdf files or "place" pdf files into a ...
PDF encrypted with EBX. How to decrypt !!
Hello I have downloaded the Advanced PDF Password Recovery PRO 2.12 but when I open a PDF document the program says: "This document was created with ebook exchange (ebx_handler) 64-bit security v.4 encryption handler. This protection metod is not supported" What can I do? There is no way to decrypt my document? It's very important, so I'm waiting your reply. Sorry about my lenguage, but I'm a spanish user. Thank you ...
PDF TO PDF MULTIPAGES
Hello, (gs 8.54 -Windows XP) i try this to convert a pdf file to one pdf file per page: gs.exe -sDEVICE=pdfwrite -o c:\fic-%d.pdf -q c:\colle.pdf It doesn't work. Is works with jpeg files: gs.exe -sDEVICE=jpeg -o c:\fic-%d.jpg -q c:\colle.pdf Thanks for Help. Christophe BADET Christophe BADET wrote: > Hello, > > (gs 8.54 -Windows XP) > i try this to convert a pdf file to one pdf file per page: > > gs.exe -sDEVICE=pdfwrite -o c:\fic-%d.pdf -q c:\colle.pdf > It doesn't work. > Is works with jpeg files: > gs.exe -sDEVICE=jpeg -o c:\fic-%d.jpg -q c:\colle....
4x PDF Help
Hi Everyone -- we've launched a new question and answer site for all PDF questions. It's based on the highly popular technology platform used by StackOverflow.com, and provides a great environment for getting your questions answered and answering other people's questions. Check it out --> http://help.4xpdf.com/ Cheers, - Rowan. ...
PDF::Writer, create pdf and insert in other pdf file.
Hi folks(wharever it mean my english is so bad...) the following code create a PDF: #!/usr/bin/ruby require 'pdf/writer' pdf = PDF::Writer.new pdf.text "Hello Matz", :font_size => 22 pdf.save_as "novo.pdf" ######################################## now I wanna save this pdf as a last page of a existing pdf. any tips? -- Posted via http://www.ruby-forum.com/. On Wed, Mar 26, 2008 at 1:23 PM, Ricardo Pog <ricardo85x@gmail.com> wrote: > Hi folks(wharever it mean my english is so bad...) > > > the following code create a PDF: > >...
For anyone struggling to figure out how to create a PDF in SWX it's pretty simple but you may have to have the Bluebeam version of swx FIRST go to Tools>Options and check "Save as PDF" Then you can save them right from the save as dialog. Maybe I'm the only dumbass that could't figure that out! ;0) But it was in help under "PDF" An easier way is to download a program from www.pdf995.com that "prints" you files to a PDF foramat. This program works with SW and any other program you use to print with. "3d" <jmiller at marvelindustri...
Postscript to PDF with pdf-tools, pdf-writer, or other
Does anyone have a way to convert Postscript to PDF using pdf-tools, pdf-writer, or other method? Any suggestions? On 14/04/2008, Sean Nakasone <seannakasone@yahoo.com> wrote: > Does anyone have a way to convert Postscript to PDF using pdf-tools, > pdf-writer, or other method? Any suggestions? ps2pdf is standard on any install of Ghostscript, at least on most flavours of Linux/BSD Farrel ...
PDF TO PDF/A
Hello, is it possible to convert a PDF file to PDFA file ? i tried the -dPDFA option and i vefy my pdf file with PDF longlife. I have an error. Thanks for help. ...
pdf \ text (get rid of text in pdf)
Is there a way to remove all text from PDF? Will extract images work for you? If so, PDF-Tools by Tracker Software will do it. http://www.docu-track.com/ -- Don Vancouver, USA "MarosV" <maros.vranec@gmail.com> wrote in message news:ebb897e1-c8e3-4b3a-9274-dfd9d2c845c3@c4g2000hsg.googlegroups.com... > Is there a way to remove all text from PDF? ...
ANN: Fly Text to PDF
Hi All: Fly Text to PDF 1.3 is powerful tool which can convert your text files into PDF. This tool is powerful converter tool running on Microsoft Windows Operating System. You can use this tool to convert your text report, text documents and other text files into PDF quickly and easily. You also can set the PDF properties in each text files by using special tags, or set the default properties for every output PDF files. Please visit our website for more information: http://www.medafan.com/pdf-tools For the output sample, please click on: http://www.medafan.com/pdf-tools/license.pdf Key fea...
Convert PDF image to PDF text
Hi, I have a PDF file with image text documents. hence I can't search the text. How can I convert it to searchable PDF file? Thanx You will have to scan it using an OCR (Optical Character Recognition) application and then create a PDF file. -- Don Vancouver, USA <WhiteLen@gmail.com> wrote in message news:1193737890.691267.165820@z9g2000hsf.googlegroups.com... > Hi, > > I have a PDF file with image text documents. hence I can't search the > text. How can I convert it to searchable PDF file? > > Thanx > Any recommendation for OCR application? ...
convert PDF images to PDF text (OCR)
Hi, I have a book which was entirely scanned into a PDF, there are approximately 300 pages. The problem is that each page is an image of the paper page, not selectable text. How can I convert this PDF made of images to a text-selectable PDF? Or directly convert it to Word? I suppose I'll need some form of OCR. Thanks in advance, Raphael Yes, since you have an image, you need to OCR it into data. You will not have much luck with any formating info, but most OCR programs today to a pretty good job if the image is fairly clean . Larry T. larrynospam@nospamjbmsystems.com wrote in message...
scanned image pdf to searchable text pdf
We have a lot of pdf files that are just scanned images of documents. How easy is it to change these into pdf's that we can search for specific words. I believe Adobe Acrobat Capture will do this when the document is originally scanned, but can it use pdf's that have already been created. If it can, can this process be automated to convert 100s of pdf files? Are there other alternatives to Adobe Acrobat Capture as it is not cheap for a large number of documents? I am new to this, so please keep it simple. Thanks for any help. Adrian HI, As you indicated, your pdf's are ...
Encapsulated PDF Storage and Encrypted PDF file
Hi there, There is no such DICOM attribute as 'Encrypted PDF' ? This attribute would be used to identify whether the DICOM file encapsulate an encrypted PDF file or not... Just a random thought, -Mathieu ...
Embedding PDF into PDF ?
I have read from websearching that it is possible to embed a smaller PDF into a main PDF, but cannot find out how this is done. Would I have to open the PDF as a text file and have my program locate a certain PDF command, then literally just stream the raw smaller PDF into it ? Any links or info would be very much aprpeciated Thanks Paul On Wed, 14 Jul 2004, Paul Champan wrote: > I have read from websearching that it is possible to embed a smaller PDF > into a main PDF, but cannot find out how this is done. Do you want to merge 2 pdf files or "place" pdf files into a ...
PDF encrypted with EBX. How to decrypt !!
Hello I have downloaded the Advanced PDF Password Recovery PRO 2.12 but when I open a PDF document the program says: "This document was created with ebook exchange (ebx_handler) 64-bit security v.4 encryption handler. This protection metod is not supported" What can I do? There is no way to decrypt my document? It's very important, so I'm waiting your reply. Sorry about my lenguage, but I'm a spanish user. Thank you ...
PDF TO PDF MULTIPAGES
Hello, (gs 8.54 -Windows XP) i try this to convert a pdf file to one pdf file per page: gs.exe -sDEVICE=pdfwrite -o c:\fic-%d.pdf -q c:\colle.pdf It doesn't work. Is works with jpeg files: gs.exe -sDEVICE=jpeg -o c:\fic-%d.jpg -q c:\colle.pdf Thanks for Help. Christophe BADET Christophe BADET wrote: > Hello, > > (gs 8.54 -Windows XP) > i try this to convert a pdf file to one pdf file per page: > > gs.exe -sDEVICE=pdfwrite -o c:\fic-%d.pdf -q c:\colle.pdf > It doesn't work. > Is works with jpeg files: > gs.exe -sDEVICE=jpeg -o c:\fic-%d.jpg -q c:\colle....
4x PDF Help
Hi Everyone -- we've launched a new question and answer site for all PDF questions. It's based on the highly popular technology platform used by StackOverflow.com, and provides a great environment for getting your questions answered and answering other people's questions. Check it out --> http://help.4xpdf.com/ Cheers, - Rowan. ...
PDF::Writer, create pdf and insert in other pdf file.
Hi folks(wharever it mean my english is so bad...) the following code create a PDF: #!/usr/bin/ruby require 'pdf/writer' pdf = PDF::Writer.new pdf.text "Hello Matz", :font_size => 22 pdf.save_as "novo.pdf" ######################################## now I wanna save this pdf as a last page of a existing pdf. any tips? -- Posted via http://www.ruby-forum.com/. On Wed, Mar 26, 2008 at 1:23 PM, Ricardo Pog <ricardo85x@gmail.com> wrote: > Hi folks(wharever it mean my english is so bad...) > > > the following code create a PDF: > >...
Web resources about - current state of FOSS tools for PDF encryption/decryption - comp.text.pdf
Encryption - Wikipedia, the free encyclopediaFor technical reasons, an encryption scheme usually uses a pseudo-random encryption key generated by an algorithm. It is in principle possible ...
REPORT: Facebook’s Outdated Web Encryption Technology May Have Enabled PrismFacebook still uses encryption keys with 1,024-bit lengths, while the industry standard used by Internet companies — including Apple, Microsoft, ...
Search Twitter - encryption
Sign in Sign up Search Refresh Tech Investor News @ TechInvestNews 2m Secusmart puts its BlackBerry encryption chip to work on the desktop (Netflash) ...
Sign in Sign up Search Refresh Tech Investor News @ TechInvestNews 2m Secusmart puts its BlackBerry encryption chip to work on the desktop (Netflash) ...
Hide Text - Text encryption and secret messages on the App Store on iTunesGet Hide Text - Text encryption and secret messages on the App Store. See screenshots and ratings, and read customer reviews.
California bill over encryption backdoors could prevent Apple from selling iPhones on its home turf... These proposed bills in California and New York fly in the face of that policy. Along similar lines, the UK is also considering anti-encryption ...
AT&T’s CEO thinks Congress, not Silicon Valley and Apple, should make encryption policy... Randall Stephenson, speaking at the World Economic Forum in Davos, Switzerland, made clear who he thinks should be leading the charge on encryption ...
AT&T CEO won’t join Tim Cook in fight against encryption backdoors... (credit: AT&T) US politicians have been urging tech companies to weaken the security of smartphones and other products by inserting encryption ...
The NSA has a brilliant stance on encryptionDiscussions about the U.S. government’s need for breaking encryption have intensified following the mid-November attacks in Paris. Law enforcement ...
Google, Apple among tech giants urging US to support encryptionThe companies, along with security experts, say President Obama should protect user data, putting them in direct competition with the country's ...
AT&T CEO thinks Apple should give up on protecting encryption
Apple is a fierce defender of its customers’ privacy, which is why every iPhone and iPad has its data encrypted by default. But according to ...
Apple is a fierce defender of its customers’ privacy, which is why every iPhone and iPad has its data encrypted by default. But according to ...
Resources last updated: 1/25/2016 4:55:41 AM