E-book security via PDF stamping (a DRM alternative)

[E-junkie_Guru]

It's actually the layering/compositing features of the PDF spec that allow us to stamp the files; if the file is not a PDF, then the stamper app won't work. The stamper also has no way to unzip files, and even if it did, that would create a fulfillment-timing problem, since each file has to get stamped on-the-fly for each buyer only after payment is completed, and that already takes longer than we'd prefer just selling single PDFs, and especially for large or complex PDFs.



Additional stalling tactics to cover the extra delay required to unzip and rezip a collection of files (not to mention the additional time to stamp more than just one PDF) would only defer buyers' gratification even further, making for an unsatisfactory buyer experience. Moreover, what if not all the files in the .zip are PDFs? What if they have different authoring passwords? What if, what if... It opens a huge can of worms that reintroduces the very problem we'd introduced stamping to avoid, namely, the unsatisfactory buyer experience of DRM-style approaches.



Have you considered simply recompiling each of your PDF file collections into a single PDF for each bundle?

[geek]

PDF Stamping is not working for me.



o Seller Admin > View/Edit/Delete Products -> select Send transaction data to a URL -> -> Enter the following URL in payment variable information URL: -> Submit



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



Note: I don't have an editing/authoring password on the PDF file. So, I've removed the &pdf_pwd= as per the documentation.



I still don't see the stamping. Can someone help? Please take a look at the document that is on my account and let me know whether anything is wrong in the PDF file that I've uploaded.



Note: I created the PDF file using Adobe PDF creator directly from Microsoft Word.

[cris]

Suppose we continue to give e-junkie a pdf file rather than a zip. Along with the name to zip the file into when the pdf stamping has been added.



As an ex-software developer, it seems that this would be far simpler, and take way less time that requiring e-junkie to unpack a pdf before adding the pdf stamping customization.



A zip would also provide a faster download, which might compensate, and perhaps even more than compensate for the extra time needed to zip the resultant pdf.



This would go a long way to satisfying the basic need, without needing a rewrite of the whole system for unusually complex non-standard requirements...

[jimbob]

TysonAdditional stalling tactics to cover the extra delay required to unzip and rezip a collection of files (not to mention the additional time to stamp more than just one PDF) would only defer buyers' gratification even further, making for an unsatisfactory buyer experience.



...



Have you considered simply recompiling each of your PDF file collections into a single PDF for each bundle?

Yes I have considered this.. and this is what we'll be doing as a "fix" for now.



However... I don't really see how your logic makes sense.



The number of pages needed to "stamp" is identical regardless of whether we have two eBook files or one file. (If we take two 50 page ebooks and combine them into a single 100 page ebook.. isn't that the exact same amount of work for the stamping process? Does opening a PDF file really take that much additional processing?)



What you are saying as being the problem (slow stamping, delayed customer fulfillment, etc) doesn't make sense if you then turn around and suggest a possible "fix" is to simply add all the ebooks into one.



What am I missing?

[E-junkie_Guru]

Unzipping and (especially) rezipping files takes a lot longer than simply stamping a PDF file as-is. That's the additional, unacceptable delay I was referring to. At any rate, even if you'd find the added delay acceptable, we simply don't have any way to automate unzipping, stamping and rezipping, so we'd have to program that whole routine. We hadn't even thought of that when we wrote the Stamper in the first place, so at present it's only capable of stamping a single PDF file at a time. Development will put your request on the wishlist, but we can't promise it'd get done anytime soon considering everything else they're already working on.

[jimbob]

Ok.. let's throw aside the unzipping issue for a bit. That's fine, and I understand the reasoning behind that.



However, what I don't understand is why you can't stamp a multi-file item. (ie: An item that includes multiple pdf files.



How is that any different then if we combine the two files into a single PDF?



There is no file to unzip/zip in that case.



No?

[E-junkie_Guru]

That is answered in my response to this suggestion:

CrisBCTSuppose we continue to give e-junkie a pdf file rather than a zip. Along with the name to zip the file into when the pdf stamping has been added...

The problem is the requirement to stamp a whole collection of separate PDF files that would be issued as a single product together, and we have no way for sellers to upload multiple files for a single product in the first place, other than compressing them into a single .zip that is simply issued to buyers as-is. The PDF Stamper currently won't even work with "package deal" bundles using the "Package files from other products" feature; it can only stamp a single PDF file that is uploaded for the exact product configured with the PDF Stamper URL.

[jimbob]

This is software. Anything is possible. :)



I hope you'll consider this as a feature request. (The ability to stamp multiple PDFs selected in the "Package files from other products" feature.)



Thanks.

[leena]

Hi, guys!



Just joined e-Junkie today and downloaded my ebook. I tried to get the pdf stamping to work, but it doesn't show. My situation is identical to Geek's on top of this page:



"PDF Stamping is not working for me.



o Seller Admin > View/Edit/Delete Products -> select Send transaction data to a URL -> -> Enter the following URL in payment variable information URL: -> Submit



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



Note: I don't have an editing/authoring password on the PDF file. So, I've removed the &pdf_pwd= as per the documentation.

"



My file is not zipped, I don't have a password and I also removed the &pdf_pwd= as adviced.



So what should I do??



Leena

[E-junkie_Ninja]

Did you test this with a free checkout or the Send Free Link option? The Send Free Link option does not attach the PDF stamp. If you are using the free checkout, make sure you wait at least 15 minutes after setting up the PDF stamping before you test the free checkout.

[leena]

Oh yes I did use the Send free link option! Never thought that would not attach the stamp. (Good point to remember in the future, thank you!) So I could be certain the stamp is there?



Leena

[E-junkie_Ninja]

Yes, the stamp is likely there. You can test it by running a free checkout for the product. Here is a link to our testing help page:

http://www.e-junkie.com/ej/help.test.htm

[leena]

Thank you so much :)



Leena

[puppetsnprops]

I'm new on E-Junkie, but something I ran into while setting up the PDF stamping, might be of help to someone else. When checking into the service, I downloaded the sample stamped PDF. In the content, it has the URL for making it work....



http://www.ejunkie.

com/ecom/o_plug.php?ej_stamp_pdf=true&pdf_pwd=ZZ&pdf_allow_copy=y&pdf_allow_

print=y



Which I copied and pasted into my Admin page for the stamping. I tested the stamping on one of my PDF documents, but couldn't get it to work after several tries. Finally, I found it. When I copied the URL from E-Junkie's test PDF, for some reason it leaves out the 'dash' in e-junkie. Look closely at the URL above (www.ejunkie; no dash!).



Not sure why it does that, as the dash shows up in the document and when you highlight it for copying, it shows as being there.



My guess is that I'm not the first person nor the last that that will happen to. Not sure if there's a way to fix that in the PDF so it doesn't do that. But fixing it or making it known, could cut down on some tech time.



Hope that helps someone! At the very least, would like to make support aware of it as a possibility why someone may be having trouble getting the stamping to work. Mine works fine now and is a great part of the service. Thanks for making this available!



Mike Brose

http://www.puppetsandprops.com

[gmp]

I have one product but we sell it in two formats--but the same content, so buyers get both for one total price. It's a travel guide and they wouldn't buy one or the other, but rahter one is to read on a screen, and the other to print. I can't split them and say one is price A and one is price B as they're part of one package which we've sold as a zipped file until now. But we really would like the security stamp on them.



I want buyers to be able to download them from one single sale, but for both documents to get stamped in the process.



Is it possible to set up a process like this:



Buyer buys product--one PDF file--and downloads it, stamping complete.

Throughout this process I include a link for them to download the other version, no extra cost, which also gets stamped?



Essentially, how can I ensure that both files are stamped without conducting two different sales?



Thank you.

[E-junkie_Guru]

Our stamper can only stamp a single PDF for each product; it cannot stamp any PDFs contained in .zip files, nor can it stamp multiple PDFs offered for a single product using our "package files" bundling feature.



Is there a reason why you need to provide two different PDFs for printing vs. onscreen viewing of the same content? Typically PDFs are designed to work either way, so any given file is print-ready but also easily viewable onscreen in a PDF reader program.

[gmp]

Thanks for this. Is there any way of making it possible that when the buyer buys one file, the other one shows up in the buying window in a form that makes it impossible to remove it? I will still charge the same total price, but they receive the two files separately and one will be a token low price?



Yes it's a 278 page travel guide and one version is designed for large screen reading and completely different aesthetically than the version designed for iPhones or printing. One is colour, 1.5 spacing, 12 point font; the other is black and white and single line spacing, 10 point. So far customers have loved having both versions. They read one on the screen at home while preparing, and if they have a lap top they use this version while traveling too. But others prefer the small print version for traveliung, but use the larger one beforehand on their PC.



I'd like both to be available to them without having to Zip it.

[E-junkie_Monster]

It might be possible to use a multi-add button to add both versions to the cart at the same time in one click, however there is nothing to prevent one or the other from being removed once that is done.



There are several forum posts on the subject, you can view one of them with the necessary JavaScript code to get you started here:

http://www.e-junkie.com/bb/topic/2428



If you decide to experiment with the multiadd code, please understand that it is basically an unsupported "hack" of our existing button code. It can work, but it isn't something that we can actively assist you with implementing and I haven't done any experimentation with that and the PDF stamping feature.

[pipo]

Could I send you my PDF, which is password protected (read only) ...

I am trying to stamp it which works well, but only if without a read only password.

As soon as I add a read only password it does not work, even though I add the pdf syntax in the URL ...



It would be important for me to add a password for opening PDFs.

[E-junkie_Guru]

Make sure the document's password security compatibility is set to "Acrobat 5.x or earlier". If there is a Master password in addition to the User (read-only) password, put the Master password in the Stamping URL; otherwise put the User password in the URL if the file has no Master password.



If you can get the Stamper to work, but it doesn't seem to retain the original User password, try adding a Master password which is different from the User password, put that Master password in the Stamping URL, then see if the User password is retained in that case. If not, then that's just the way it has to be with your particular file. Note that the Stamper always adds a random Master password to the file anyway, which prevents any extraction or other tampering with the document's content and settings.



Bear in mind that even using a User password in this scenario, where you are giving out the password along with the file, effectively does nothing to improve the file's actual security nor discourage sharing, since anyone who wants to share the file would simply include the password. It's like locking something with a padlock but then leaving the key right there in the lock, so what's the point of locking it at all if everyone has the key?