Amazon and DRM changes

[Alaska]

Originally Posted by Quoth

DRM free ebooks are only so in mobi/azw/azw3 etc. KFX has a generic DRM for any Kindle App, Fire or KFX capable Kindle eink, not linked to device, even if the publisher says DRM free and the azw3 (Download for USB transfer to eInk Kindle and only outright bought ebooks).

The only KFX free ebooks are home made and even with Calibre the KFX output tool seems to need an Amazon program that's not available on Windows.

KFX is useless.

Mobi or AZW books don't have pairkerning, so so far I have downloaded all purchases from Amazon as AZW and converted them to KFX with Calibre. You need the Kindle Previewer for this, which is also available for Windows: https://www.amazon.com/Kindle-Previe...de=21381691011

If I don't get AZW files from Amazon anymore (so far it works for me even for books published in January 2023), I buy EPUBs without hard copy protection and convert them to KFX because the typeface is better.

Otherwise, I hope someone manages to remove the hard copy protection from KFX. I would never buy an ebook that I can't edit. Most ebooks are poorly formatted.

[ownedbycats]

Originally Posted by Alaska

Otherwise, I hope someone manages to remove the hard copy protection from KFX. I would never buy an ebook that I can't edit. Most ebooks are poorly formatted.

Fairly difficult, unfortunately. tl;dr, take with a grain of salt thanks to my shaky memory: KFX DRM has at least 40 implementations. Only 10 have been used so far. Whenever the DeDRM/NoDRM team breaks one, Amazon switches to another (sometimes within hours). So all 40 would need to be broken at once, which is hard to do because there's no books actually using them to test that it's working.

[Quoth]

Originally Posted by Alaska

Mobi or AZW books don't have pairkerning

The pair kerning isn't in the format, but the renderer implementation.

Making your own KFX:

Originally Posted by Alaska

You need the Kindle Previewer for this, which is also available for Window

Not on Linux.

[JSWolf]

Originally Posted by hyegeek

That wasn't true when I tried it. I have the latest deDRM and I'm using caliber. The DRM free book I bought and did not convert I had to transfer it via an eink Kindle. The error specifically said that it had DRM

The correct name is Calibre.

The reason is that ALL KFX has DRM.

[ownedbycats]

Note that some versions of KFX can be broken by DeDRM. But you can only get these in specific ways.

[JSWolf]

Originally Posted by ownedbycats

Fairly difficult, unfortunately. tl;dr, take with a grain of salt thanks to my shaky memory: KFX DRM has at least 40 implementations. Only 10 have been used so far. Whenever the DeDRM/NoDRM team breaks one, Amazon switches to another (sometimes within hours). So all 40 would need to be broken at once, which is hard to do because there's no books actually using them to test that it's working.

Breaking KFX DRM would have to be done one at a time until all 40 are broken and even then I can see Amazon releasing new firmware that has a new set of 40 DRM versions.

[JSWolf]

Originally Posted by Alaska

Mobi or AZW books don't have pairkerning, so so far I have downloaded all purchases from Amazon as AZW and converted them to KFX with Calibre. You need the Kindle Previewer for this, which is also available for Windows: https://www.amazon.com/Kindle-Previe...de=21381691011

If I don't get AZW files from Amazon anymore (so far it works for me even for books published in January 2023), I buy EPUBs without hard copy protection and convert them to KFX because the typeface is better.

Otherwise, I hope someone manages to remove the hard copy protection from KFX. I would never buy an ebook that I can't edit. Most ebooks are poorly formatted.

I know you don't get kerning with KF8. But you can get hyphenation by adding sort hyphens And one thing you cannot do with KFX that you can do with KF8 is reduce the line spacing by using a font that has the metadata for a smaller line height such as ChareInk6 or ChareInk6SP both available at https://www.mobileread.com/forums/sh...d.php?t=184056

[ownedbycats]

Originally Posted by JSWolf

Breaking KFX DRM would have to be done one at a time until all 40 are broken and even then I can see Amazon releasing new firmware that has a new set of 40 DRM versions.

Now that I'm more awake, here's jhowell's post from the NoDRM github:

Amazon has implemented around 40 different DRM algorithms for KFX. They are built into the various Kindle apps and device firmware as highly obfuscated code.

Each algorithm is identified with the letter V followed by a number. So far DeDRM handles V1 though V10. Amazon is currently using V11, which DeDRM attempts to decrypt but does not do correctly.

As things stand now anyone who does figure out how to defeat the current V11 DRM has a strong incentive to keep it to themself. Keeping it quiet would mean that at least they could make use of it. Making it known to the world would just result in Amazon switching to V12, causing all of that hard work to be for nothing.

In order to defeat KFX DRM in DeDRM all of the thirty or so remaining DRM algorithms would need to be reverse engineered. If any are gotten wrong, which is likely without a way to test them properly, Amazon would immediately use that one for now and then keep adding more new ones over time.

Even if someone managed to get all of the algorithms correct, DRM removal would only work until Amazon deployed software with more new algorithms and blocked downloads to the older software.

[JSWolf]

Originally Posted by Alaska

Otherwise, I hope someone manages to remove the hard copy protection from KFX. I would never buy an ebook that I can't edit. Most ebooks are poorly formatted.

The hard DRM for ePub (ADE) has been broken. The current code for the DeDRM plugin at the github should remove the hardened DRM.

[Alaska]

Originally Posted by JSWolf

The hard DRM for ePub (ADE) has been broken. The current code for the DeDRM plugin at the github should remove the hardened DRM.

I use the DeDRM plugin for KF8, for ePubs this is not necessary in Germany because you can buy them without hard copy protection. They use soft copy protection, 'watermarks' and the buyer's name is hidden in the text in encrypted form. That's why I preferred the hard protection of KF8, which you could remove completely.
There are also other advantages with Amazon: I can download ebooks I bought even after 13 years, even though they are no longer available. ePubs are only available here for two years, at least that's what the purchase contract says. Amazon offers audio books at a reduced price with the ebooks and the possibility to read/listen to them alternately ("Whispersync for Voice").
But I'd rather secure my books better, pay more for audiobooks and live with soft copy protection than make friends with KFX DRM.

[j.p.s]

Originally Posted by JSWolf

The correct name is Calibre.

Kovid Goyal spells it as calibre.

[ownedbycats]

Originally Posted by Alaska

I use the DeDRM plugin for KF8, for ePubs this is not necessary in Germany because you can buy them without hard copy protection. They use soft copy protection, 'watermarks' and the buyer's name is hidden in the text in encrypted form. That's why I preferred the hard protection of KF8, which you could remove completely.

If it doesn't prevent access and it's for your own personal use, why are watermarks an issue?

[Alaska]

Originally Posted by JSWolf

I know you don't get kerning with KF8. But you can get hyphenation by adding sort hyphens And one thing you cannot do with KFX that you can do with KF8 is reduce the line spacing by using a font that has the metadata for a smaller line height such as ChareInk6 or ChareInk6SP both available at https://www.mobileread.com/forums/sh...d.php?t=184056

I correct and format almost every ebook (ePub, KF8), also the line spacing, this was transferred correctly to KFX so far. The spacing between the letters when there is no kerning bothers me extremely. I still have the Kobo H2O and if I remember correctly it was similar with kepubs that they had kerning and the corresponding ePubs did not.

[Alaska]

Originally Posted by ownedbycats

If it doesn't prevent access and it's for your own personal use, why are watermarks an issue?

I have read that the text in the book can also be changed slightly. However, that was a while ago and I don't know if it is done that way.
I often buy ebooks and audiobooks of the same title from Amazon and use Whispersync for Voice. This is no longer possible when I buy the ebooks elsewhere.

[Patitapetit]

Originally Posted by ownedbycats

Fairly difficult, unfortunately. tl;dr, take with a grain of salt thanks to my shaky memory: KFX DRM has at least 40 implementations. Only 10 have been used so far. Whenever the DeDRM/NoDRM team breaks one, Amazon switches to another (sometimes within hours). So all 40 would need to be broken at once, which is hard to do because there's no books actually using them to test that it's working.

I think It is Impossible the 39 Algorithmen are very different