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May 2009

For our merchants selling e-books in PDF format, we have been working on a couple of ways to protect their PDFs from distribution.



We tried the DRM angle, but it was really making the buyer experience poor, was not supported by all the PDF readers and it was apparent that in various scenarios, it can cause additional customer support issues for the merchants to handle. So, we decided to scrap that.



And then we worked on the PDF stamping feature .. basically, we can now stamp the buyer's name, e-mail and the transaction ID on the top-left of each page of the PDF before the download. Unlike DRM, this is a simple, non-intrusive way to discourage buyers from sharing their PDFs.



EDIT: Please see current documentation for PDF Stamping in our help pages here:

45http://www.e-junkie.com/ej/selling-ebooks.htm45

This sounds like just what I need. I have one quick question. Does this work if the PDF file is zipped?

This will not work if your PDF file was uploaded within a .zip file. It will only work with PDFs uploaded as an actual .pdf file.

How would this work for updates I send out with Semd Updates/Newsletter ?

Is there any possibility that support for zipped PDF files could be added? It seems to me it shouldn't be too tough to unzip, stamp and re-zip the PDF file.....

pcunixHow would this work for updates I send out with Semd Updates/Newsletter ?





It won't work with that or the free links. It will only work for checkout (free or paid)

PayloadMediaIs there any possibility that support for zipped PDF files could be added? It seems to me it shouldn't be too tough to unzip, stamp and re-zip the PDF file.....





If more people start using the stamping feature and we find this to be a common request, we'll do this.

Nice feature but it's useless to me because I regularly send free updates.

1)How about secured pdf, the one with security password added for opening and editing the pdf.. Is it still works?



2)Without zip function we will on disadvantages, the pdf will automatically load to browser and if user didn't save it and we have limitation to 3 times download the user will face this is not user friendly.. If we using zip this will go directly to their hard drive..

8 days later
Zack1)How about secured pdf, the one with security password added for opening and editing the pdf.. Is it still works?




Yes, the URL I've mentioned above has a parameter which lets you specify the password.



Zack2)Without zip function we will on disadvantages, the pdf will automatically load to browser and if user didn't save it and we have limitation to 3 times download the user will face this is not user friendly.. If we using zip this will go directly to their hard drive..





Any file being served via E-junkie, whether it's a ZIP or a PDF .. will prompt the user with the option to either save it, or open it.

Just wanted to post that we've updated our code so we can now also handle pages which have images covering the whole page.

Awesome! Will add it to my next product. This is just what I need.

i easily got lost there. is there a video tutorial for this? lol

pcunixHow would this work for updates I send out with Semd Updates/Newsletter ?





Could you make the updates available as a free download and just send the link to the update page only to your list of registered buyers - surely that would do the trick? (No-one but a registered buyer would get access to the download link - and you could still use the stamping feature so your updating buyers will still be discouraged from "sharing" theri updated files)



Hope this helps!

I'm doing exactly what the PDF instructs me to do. I am not able to get the stamping on either a password protected PDF or a regular unprotected PDF.



I put a check mark next to "Send Transaction Data To A URL", then hit next, then in the "Payment Variable Information URL" I type in "http://www.ejunkie.com/ecom/oplug.php?ej_stamp_pdf=true&pdf_pwd=gatsby92%%320#&pdf_allow_copy=n&pdf_allow_print=y"



I do the same thing for an unprotected PDF but I take out "&pdf_pwd=gatsby92%%320#"



Why isn't this working for me? Can I use % and # in the password? Am I putting a check next to the correct boxes?

I'm also downloading it using a "Free download Code", maybe this is why it isn't showing up?

also...does this security work if we are hosting the file on the e-junkie server?

also...does this security work if we are hosting the file on the e-junkie server?

@Gatsby:

I think your PDF file password could be the problem. It's got some characters that work as special characters in a URL, and since you need to put the password as-is into your Payment Variable Info URL for the PDF stamping, that isn't going to work. Try changing your PDF password to something entirely alphanumeric, or at least limit your use of symbols to these: $-_,+!*'().



@MatthewCornell:

Not sure I follow what you mean? Caveat #4 only affects the buyer's original download link. If you send out an update newsletter with fresh links, or use the "Send free download link" feature in Seller Admin, that sends a new link for the most current edition of the file.

That is a cool idea. Could you do the same with 1280 x 720 video? Like a small unobtrusive watermark in the corner?

Please help - I Couldn't get it to work. Steps:



o Select: Seller Admin > View/Edit/Delete Products

o Select: desired product

o Click: Edit

o Check: Send transaction data to a URL

o Click: Next

o Enter into: "Payment variable information URL" the following:

http://www.e-junkie.com/ecom/oplug.php?ej_stamp_pdf=true&pdf_allow_copy=y&pdf_allow_print=y

o Click: Next

o Click: Submit



o Select: Seller Admin > Send free download link/code

o Enter your own email address and click: Submit

o Copy: Link Activitated link and paste into browser window

o Click: Click here and check the PDF



In my case, I don't see the stamp. What am I doing wrong?



Thanks,



matt



--

Matthew Cornell | matt@matthewcornell.org | 413-626-3621 | 34 Dickinson Street, Amherst MA 01002 | matthewcornell.org

11 days later

Will this work if I've made a PDF(s) that's password protected from Adobe Acrobat to accomplish the following:



1. Printing disabled.

2. Any copying of content is disabled.





Thanks

I don't have either a password, nor am I hosting it on my own servers, and I am not getting the time-stamp when I do a free download. I clicked the option to send transaction data to URL. Other ways to debug?



Nevermind -- it is working -- I needed to log in using a new email

MatthewCornell

In my case, I don't see the stamp. What am I doing wrong?





The stamp will show up on the upper left side of the pages in your PDF. If it is not showing up check the password. The Password you are entering should be your authoring/editing password not the read-only password that your buyers will use.







JohnTKWill this work if I've made a PDF(s) that's password protected from Adobe Acrobat to accomplish the following:



1. Printing disabled.

2. Any copying of content is disabled.





We have steps for setting up these options in our first post. Here they are again:

E-junkieChef

b) Not recommended - If you do NOT want the buyer to be able to print your PDF, replace &pdf_allow_print=y with &pdf_allow_print=n



c) Not recommended - If you do NOT want the buyer to be able to copy-paste content from your PDF, replace &pdf_allow_copy=y with &pdf_allow_copy=n (note that copy-pasting is different from extraction, which we disable by default, but we do allow extraction for visually-challenged screen readers)



Ed. note - b & c are "not recommended" .. not due to technical issues, but simply due to the fact that it is not the best user experience for the buyers to not be able to print or copy content from an e-book that they have paid for.

Hi,



I have an important question related to the security of your sistem based on stamps and watermarks on PDF to avoid from copying and deploying it on a p2p system.

I'm using an approach similar to yours for selling my ebooks on my web site since a couple of years ago. I wrote my own code in C# to add the stamps and watermarks in the ebook and I protect it by owner and reader password.

I discover that using the same API I used to add the stamps I can remove the stamps and I can copy a clear pdf without any stamp or watermark in a couple of minutes.

If it is protect by passwords (owner and user) I can use PDF Remover to remove the passwords.

After that a peice of code in C# removes the stamps and watermarks saving a clear pdf that can be easily published by a pirate on p2p system.

It is really simple.



My question is: does your system avoid from that? i.e. is your system resistent to an attack as I mentioned above? (I haven't tried to crack your pdf sample yet)

If so, I'm really happy to publish my ebooks with your system.



Regards,



Ugo Chirico

http://www.ugosweb.com

http://www.cryptware.it

I downloaded the free test .pdf provided. There was no stamp with my name and email.

Like Riley, I downloaded the test pdf provided. There is no stamp on it. I uploaded my pdf file, added the URL string, and sold a copy to myself for $0 using a discount. The delivered pdf has no stamp on it. I even uploaded a fresh copy of the pdf, waited half an hour, tried again. No go. Clearly, we're doing something wrong because I believe you guys... but what are we doing wrong?

Okay, I did some experiments. The news is not good.



1. Using Adobe Acrobat 8 Standard, I set password protection on the PDF I created. The only things allowed are printing and accessibility. I uploaded it. I set URL code to http://www.e-junkie.com/ecom/oplug.php?ej_stamp_pdf=true&pdf_allow_copy=n&pdf_allow_print=y&pdf_pwd=password9. I used a discount code to buy the PDF for $0.



1.a. When clicked the download link and opened the file in Adobe Reader 9, the PDF had the stamp on it. Security on the PDF was set correctly BUT Filling in Forms was also set to ALLOWED (contrary to how I set security when I created the PDF).

1.b. I then opened the PDF in Acrobat 8 Standard (the full app). Commenting, signing, creation of template pages, filling of form fields were all ALLOWED.



2. I modified the password in the PDF to password$9 (adding a $ sign) and uploaded it again. I modified the URL string to include the new password with the $. Bought and downloaded the PDF.



2.a. The purchased PDF does not have the stamp on it. It seems the $ sign is not supported in the URL code. Security is set correctly when opened in Adobe Reader.

2.b. Security is correctly when PDF is opened in Adobe Acrobat 8 Standard. Only printing and accessibility are allowed, as I set them when I created the PDF.



3. Suspecting something odd is going on, I re-did step 1. above. I set the password back to password9 -- no $ sign. Same security settings. Uploaded the new file.



3.a. Purchased and downloaded the file the same way. Opened it in Adobe Reader 9. It has no stamp on it. Security properties are as I set them.

3.b. No difference when I opened the downloaded PDF in Acrobat 8 Standard.



My conclusion is that both the stamping feature and the security features work inconsistently.



Unless something goofy is going on on my end that I don't know about, more work needs to be done before this stamping feature will work properly and consistently. I urge e-junkie's techs to keep at it -- this is a VERY nice feature that would mean a lot. Thanks for taking on the task.

I tried one more thing.



1. Using Adobe 8 Standard I removed security password from the PDF. Uploaded it. Changed the URL string to http://www.e-junkie.com/ecom/oplug.php?ej_stamp_pdf=true&pdf_allow_copy=n&pdf_allow_print=y so the &pdf_pwd= was removed (and so printing would be turned off). Bought and downloaded the PDF.



1.a. No stamp on it. Security is as I set it in Adobe Acrobat. Printing is allowed.



For what it's worth. I thought maybe the URL string would override the NO SECURITY setting from Adobe and prohibit printing. It just left the PDF as it was, made no changes. But it also did not add the stamp.



I hope this info is useful to someone.

Hm, there does appear to be an issue with the experimental new PDF stamping feature at present. We'll post an update here when it's back online.

Hey, if new features worked the first time around, it wouldn't be new technology! Thanks -- I'll look for the stamping feature again. I'm new here, trying out the service. Very impressed so far. Hope to be up and selling next week! But please try to get the stamping worked out. It would make a huge difference to those of us selling valuable PDF's... and not wanting to get ripped off.

I would also prefer a solution for zips;

mostly I have a mixture of pdf, doc and excel sheets.

A digital stamp for the pdsf would be enough, its ok if the docs and xls data stay without a stamp

PDF stamping does appear to be working for most files currently, although we still have not found the reason why a rare few exceptional PDF files simply fail to get stamped, so we're still looking into that. At least it's an always-or-never case for each file; if your PDF is getting stamped at all, then it should always get stamped for every checkout.



Make sure you wait AT LEAST 15 MINUTES after uploading your file before attempting any checkouts to test the stamping, as our server needs to chew on the file for a while to prepare every page for stamping with each checkout.



Sorry, it is technically impossible to stamp a PDF that is encapsulated inside a .zip archive. We can only stamp PDFs that are uploaded to us as PDFs, since we take advantage of certain aspects of the PDF file spec to perform the stamping.

Tyson,



Thanks for the candid story. One question. Adobe Acrobat lets you set security across several features. E.g., you can set it to print at hi-res, lo-res, or not at all. Your settings are Y/N for printing and Y/N for copying -- those are the only settings. Acrobat lets you choose printing in hi-res or low-res. If the file is already set in Acrobat for Print=Hi-res, what happens? Do your settings over-ride the Acrobat settings?



Do your settings interfere with other security settings that Acrobat controls?



Thanks. I'm going to try again.

e-junkie test PDF displays no stamp. I think this is a great feature, I'd like to see how intrusive the stamp is.

Got the free PDF stamp to work. Great feature. Well worth the price of admission.



Now am having a problem stamping my file. I have gone through the checkout discount process but my downloaded file is not stamped. I uploaded it a few days ago so it has been "chewed on" by your server. There is no password for my file. Is this the problem? I don't want to have to have a password for my buyers to open the pdf.



Thanks for the effort.

Hm, it should be working now for most PDFs, no password should be necessary. Try this: Go back to the first post in this topic and right-click on the Payment Variable Info URL provided there to copy the link target/location, then repaste that into your PDF product's settings (and remember to remove &pdf_pwd= from the end if your file has no password) and click Next then Submit to save changes; then edit your product again and use the Overwrite Product File button to reupload a fresh copy of your PDF, and click Next then Submit again. Wait at least 15 minutes, then try a test checkout again to confirm the file gets stamped.

Still doesn't work. Repasted the url link and saved changes. then uploaded a new pdf and saved changes. waited an hour then downloaded a discounted free pdf from my site using the add to cart button. Is it the pdf file itself? or the process? should I try it with a diferent pdf from a different source?



thanks

Its the pdf file itself. I uploaded a different pdf from a different source and it worked. my first pdf was created with an aftermarket pdf program called PDFtypewriter. the second pdf file I believe was created with Adobe. I will test other pdfs from other sources. Can you look at the file I created with PDFtypewriter and see if you can get it to work. It is a much cheaper alternative to me having to buy Adobe.



Thanks