Do decrypted ePubs watermarked?

[RAH]

I agree that it is kind of difficult to meet the conditions, just from a practical matter. But I suppose it would be easy enough to find a cheap book on B&N (maybe one of their free ones - today! - would that work?) and have 2 people buy it, etc.

I agree it is not right to pirate books. However, I think it is clear that removing DRM is useful from a "fair use" perspective, or even just for archiving your books. If B&N is not around 5 years from now, will I be able to read a B&N DRM book on my new Google ereader (the latest one that's 1/2" thick and runs for a year without charging)? I won't have to worry if I have preserved a non-DRM version.

Also, if I give an epub file with the DRM removed to a friend and stipulate that they delete the file after they are finished reading it, then this is exactly like lending them a physical book (if I only lend to one person at a time). Of course, the wrinkle is that they might not delete it, and might even distribute it. Interesting topic.

[taustin]

Originally Posted by KevinH

Huh? I am claiming they are hard to meet because typical users (like me) don't normally have two copies of the exact same book bought by two different people from the exact same store with the DRM removed by the same tool on both. I strongly doubt very many people would have! Especially if they are not pirates. Is this really what you are questioning!?!

If so ... good luck with that.

It sounded like you believed that publishers routinely sell different versions of books to different customers.

[KevinH]

Originally Posted by taustin

It sounded like you believed that publishers routinely sell different versions of books to different customers.

They might if the differences are introduced to track the purchaser (say a specific sequence of spaces or typos or ...) but your test would detect that case.

[taustin]

Originally Posted by KevinH

They might if the differences are introduced to track the purchaser (say a specific sequence of spaces or typos or ...) but your test would detect that case.

That was my point, yes. Once you've stripped out any DRM, what remains should be bit-for-bit identical for all purchasers, unless they're watermarking it.

[FizzyWater]

Originally Posted by taustin

It sounded like you believed that publishers routinely sell different versions of books to different customers.

I've actually noticed small differences (mostly in the cover images) when there are freebies offered at Sony and Amazon and B&N, etc. The B&N books generally have a visible difference in the first page or so from the Sony books.

That's not the same thing you're talking about, but I found it interesting.

[dmunsil]

I note, purely out of disinterested geeky curiosity, that this could be resolved (at least for a single title) if two people purchased the same title, removed the DRM, generated a hash of the titles, and compared just the hashes. MD5 would be adequate. No need for SHA-256.

But (and here's where reading too much John LeCarre gets you) there's always the chance that they only do it for some titles and not for others. And even if they don't watermark now, they could start adding it at any time! They might only add special tracking for people they feel are likely to be distributing books over the internets! It's a conspiracy wrapped in a cabal with a side order of racketeering!

Basically you can never be totally sure without checking each individual book. But you could reassure yourself that they're not doing it as a matter of course by doing the MD5 thing.

Don

[slayda]

Originally Posted by apastuszak

I buy books and remove the DRM. I store them all in Calibre and sync to my wife's nook and to my Kindle (hence why I remove the DRM. Need to convert to mobi).

I don't give these files out anywhere, but since the DRM has been removed, there is potential for someone to "borrow" them. Hacker gets into my system or my Dropbox. Son' friend comes over with a thumb drive while I am at work, etc.

If this were to happen, something may be out there with MY name on it that I didn't put out there, and because it's watermarked in some way, I don't think legally I'd have a lot of recourse against a publisher's lawyers.

So, I am curious, is there anything on these ePubs form B&N that can link back to me?

I do understand that chances are some teenager is going to borrow music before he borrows a book, but the potential is there. People have given me m4a files that clearly still have the purchaser's metadata in them, so I know it can happen.

Going back to the original post, it seems that the worry is that his/her purchased book gets out into the pirate community because he (perhaps illegally) removed the DRM. However, what's to keep a book being taken before the DRM is removed and the pirate removing the DRM. The end result would be the same with the original purchaser's name being (perhaps) associated with the book.

[KevinH]

Originally Posted by slayda

However, what's to keep a book being taken before the DRM is removed and the pirate removing the DRM.

It is actually quite hard to "crack" the DRM if you do not have access to the key info or can not somehow limit the search domain. The current set of DRM removal keys do not work for just any book. They only work for books that you have purchased where the key to remove the DRM is properly stored on your machine. All the DRM removal software does is find the key on your machine, figure out how to manipulate it properly and use it to unlock the book. It does not "crack" anything. So a thief would have to steal all of the right key pieces from your machine/device in order to remove the DRM and even then may be foiled because some encryptions schemes are machine and user id specific.

For example, the Mobi DeDRM scheme uses an 8 character PID key (the last 2 are checksum digits) where each character is taken from the set of about 64 possible characters (all capital letters, all little letters, the numerals, plus a few other chars). To break this a computer might have to try 64 to the 8th power or 281,474,976,710,656 different possible PIDs. If the algorithm to check a single key takes even 100 milliseconds of computing time, then it may take something like 325,781,224 full 24 hour days to generate the right PID for a single machine. Obviously to forcibly "crack" these would take a massively powerful network of computers all running very very fast code.

So if someone does steal a DRM book, they are very very unlikely to be able to crack the DRM without access to the key information that is stored on the purchasers device/machine.

[JSWolf]

Originally Posted by jocampo

I would not remove the DRM, is illegal in USA

Have you been reading MR or have you just been looking at the pictures?

It's been said many time in many different threads that it is wrong to say it is illegal to strip DRM in the USA. It's neither legal nor illegal. There are two opposing laws on the books and until a judge decides one way or the other it's going to remain unknown.

We have fair use and we have DMCA. Both mostly conflict with each other. But the DMCA does have an exception that allows 100% legal DRM stripping. So even the law that says it's illegal says it's legal in some cases. So making a blanket statement saying it is illegal in the USA is at least partly wrong.

[JSWolf]

There is no watermark in an ePub eBook that has had the DRM stripped. That being said, there is no reason to keep this thread alive as the answer has just been given.

[KevinH]

Originally Posted by JSWolf

There is no watermark in an ePub eBook that has had the DRM stripped. That being said, there is no reason to keep this thread alive as the answer has just been given.

Luckily for **everyone** on MR, you are not a moderator. So I think I will simply add you to my ignore list. Please add me to yours.

[dmunsil]

Originally Posted by JSWolf

There is no watermark in an ePub eBook that has had the DRM stripped.

I agree with you that there is no obvious identifying information in any of the epubs I've looked at. But via the simple expedient of adding a watermark to the book cover jpeg or another jpeg in the package, a book could easily be tagged with a unique code that could be traced back to the original purchaser. Even if the booksellers aren't doing it now, they could certainly start any time.

I very much doubt anyone is doing so at this point, because it would cost something to get the software up and running, and it's not like it would do them much good. I suppose they could start suing people, but the backlash would be severe. They could cut off the accounts of people who put books on pirate sites. Those people would just sign up for new accounts under different names.

So broadly speaking it doesn't seem likely. But it's certainly possible to do.

Don

[taustin]

Originally Posted by dmunsil

So broadly speaking it doesn't seem likely. But it's certainly possible to do.

I don't recall anybody saying it couldn't be done, just that it would be easy to detect if it were.

[apastuszak]

Originally Posted by slayda

Going back to the original post, it seems that the worry is that his/her purchased book gets out into the pirate community because he (perhaps illegally) removed the DRM. However, what's to keep a book being taken before the DRM is removed and the pirate removing the DRM. The end result would be the same with the original purchaser's name being (perhaps) associated with the book.

I believe removing DRM in order to backup your data is considered fair use under DMCA.

If someone got their hands on my DRMed books, they would need to have the credit card number they were purchased under and the name, exactly as it printed on my credit card. If they got my encrypted ePubs, they probably would not be able to decrypt them that easily.

[apastuszak]

Removing DRM from files you don't own is definitely illegal. So, if I were to borrow Digital Editions books from the library and decrypt them that could land me in a heap of trouble. Removing DRM from my own personal property is still a grey area.

As far as I am concerned, I BOUGHT the file. It's my property, and I should be able to do with it as I please.

I just keep remembering all the WalMart and MSN Music customer that lost access to ALL their legally purchased music when both companies shut down their DRM servers.