Quote:
Originally Posted by soondai
Quote:
Originally Posted by Pablo
Probably. Likely places are metadata and images.
Personal information in the metadata can be removed even if it is encripted just by deleting any non-esential tags, but information disguised inside an image cannot be identified easily.
The only way to know if any account information is embedded in a book is to buy two copies of the same book, at the same time, using two different accounts, DeDRMing both and making a binary comparison of the resulting files.
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with all the whizs around here, I am surprised no one has done something like this |
I
have done this with ADE epubs. After removing the DRM, the files inside the resulting epubs are the same for different ADE accounts.
Each text file in the epub contains an Adobe ID, which is the ID of the book on the particular vendor's ADE server. Someone could figure out which store you bought it from, but that's about it. The line looks like this:
Code:
<meta content="urn:uuid:4c189c49-f830-4679-90ce-923d9d2ca79e" name="Adept.expected.resource"/>
That line is the same for the same book from the same server, even for different downloading accounts.
The only other thing that I can think of is that if the timestamp on the output epub (also embedded in the zip header) is close enough to when you downloaded the book from the ADE server, someone with access to the ADE server might be able to make an educated guess about who the original downloader was.
If anyone cares to "replicate my findings," it's pretty easy. First, have two installations of ADE. You can use two different computers, virtual machines, or even just different Windows accounts. I'm a fan of virtual machines and it's harder to accidentally screw up your ADE account that way, so that's what I do.
An easy place to find books that can be downloaded to multiple accounts for free is
Adobe's sample ebook library. Each download generates a brand-new ACSM file that can be fulfilled by any ADE account.
An actual ebook store that makes this easy is
eBooks.com. Though you have limited downloads for each book (usually either three or five, depending on the publisher), each ACSM download can be fulfilled by a different ADE account (unlike Kobo, which requires the same ADE account as the first fulfillment for any book). There are enough free ebooks that you should be able to satisfy yourself.
This link goes to a rivetting book about how the HCSB is the best Bible translation ever.
That ebook is pretty much free everywhere, so you can do the same thing at
Kobo or
Google Play, but you'll need access to two store accounts.
The comparison tool that I use is Scooter Software's
Beyond Compare. It will compare whole directories, so you need to unzip the two epubs, but you don't need to check each file yourself. Beyond Compare costs $30, but you can try it out for free for 30 days, even though the software doesn't ever stop working (I think it nags you after 30 days, but that's it). For people worried about watermarks in images, Beyond Compare will compare images as well. I compared Pottermore books from two accounts and found the watermarks (it amounted to a pattern of dots embedded in the images).