Extract keys from Kindle readers

[NiQ1]

Question / bug report

I have an old Kindle PW2 reader and it seems to be able to read KFX files just fine despite not having received firmware updates for years now. Many old kindle models can be jailbroken on all firmware versions, and using KUAL and kterm you can get root access. If we're somehow able to extract the keys from jailbroken kindle devices it might provide a long term solution to KFX decryption (at least until Amazon drops support for those devices).

Which version of Calibre are you running?

6.29

Which version of the DeDRM plugin are you running?

v10.0.9

If applicable, which version of the Kindle software are you running?

No response

Log output

Paste log output here.

[ElleKayEm]

Just put your Kindle's serial number into DeDRM's customization. You will also need the KFX Input plugin in addition to DeDRM 10.0.9 for KFX format.

[NiQ1]

Just put your Kindle's serial number into DeDRM's customization. You will also need the KFX Input plugin in addition to DeDRM 10.0.9 for KFX format.

This might be a stupid newbie question - but if Amazon sends KFX files that can still be read on such old readers then why does this cat and mouse game with KFX format continue?

[jonathan2183]

Because kfx drm varies from older to newer. Certain titles along with text books get stronger protection that cant be removed with plugin. Those ones with stronger protection get updated more often.

[ElleKayEm]

I'm no encryption expert, but from what I understand there are hundreds(?) of encryptions that were already built-in even to the older Paperwhite 2. Many of the few dozen(?) that Amazon has so far put in use have been figured out. But many more are available and more could be added so it can be a lot of work for nothing.