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Old 01-26-2008, 02:06 PM   #8
DaveNB
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DaveNB has a complete set of Star Wars action figures.DaveNB has a complete set of Star Wars action figures.DaveNB has a complete set of Star Wars action figures.DaveNB has a complete set of Star Wars action figures.
 
Posts: 86
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Join Date: Jun 2007
Device: Nook, Sony PRS-500, Nokia 770 (FBReader)
Quote:
Originally Posted by igorsk View Post
Yes you can. The files ARE encrypted with a key specific to your account, and decryption key is stored in Reader's keystore when you register it.
Interesting.

That is more time/resource intensive for Sony as they have to create a custom file encrypted for each account on the fly/at the time of purchase. But Crypto wise, it's much more secure assuming they're using public key encryption. This way only the Public/Decryption keys are out there in user's hands and there is no way (hopefully if they used a good encryption method) to derive their Private/Encryption keys (specific to each account) that they hold exclusively on Sony's servers.

Less flexible than if their books were encrypted with a global Private Key for all books, with the Public Key embedded in each book that is further encrypted by the individual device's/account's specific key. This way the whole book doesn't have to be re-encrypted over and over for each purchase but only the portion that is the decryption key. But some crafty hacker could intercept the embedded global Public/Decryption Key during it's unscrambling process and subsequently be able to unscramble ALL eBooks...

The first (more secure as their master encryption key never leaves Sony's control and there is no one key that will unlock all eBooks) method requires a sophisticated key management database and more horsepower on their end to do all the whole file encryption on the fly. But then again, eBooks aren't huge files (as opposed to let's say really high bitrate music or video) so given modern computing resources, this added processing overhead is trivial.

This is all in theory anyways as we don't know exactly how it all works.

Quote:
Originally Posted by igorsk View Post
Filename doesn't matter. However, you'll have to reimport renamed files into the eBook Library.
Cool, thanks that is good to know as I've been renaming my purchased files to something I can recognize more easily for archival purposes.

It's great to know that they are totally self contained and I can use another program (non Sony Library software) to reload them onto the Reader in the future.

Thanks,

Dave

Last edited by DaveNB; 01-26-2008 at 02:08 PM.
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