MobileRead Forums - View Single Post - Firmware Update New Kindle software update: 5.18.4

jhowell · 07-31-2025, 11:17 AM

I took a quick look at the 5.18.4 firmware update and two things stood out to me.

First, there appears to be added checking of the integrity of image file formats. I wonder if that has anything to do with the upcoming jailbreak method that was apparently closed in this firmware update.

There are also signs that Amazon is working to include a second factor (ACCOUNT_SECRET) in the KFX DRM used for e-ink Kindle books. If so that would lock down the DRM so that it will be impossible to remove unless the Kindle is jailbroken. Even then it would require further research and development to make DRM removal possible.

07-31-2025, 11:17 AM	#12
jhowell Grand Sorcerer Posts: 7,119 Karma: 92500001 Join Date: Nov 2011 Location: Charlottesville, VA Device: Kindles	I took a quick look at the 5.18.4 firmware update and two things stood out to me. First, there appears to be added checking of the integrity of image file formats. I wonder if that has anything to do with the upcoming jailbreak method that was apparently closed in this firmware update. There are also signs that Amazon is working to include a second factor (ACCOUNT_SECRET) in the KFX DRM used for e-ink Kindle books. If so that would lock down the DRM so that it will be impossible to remove unless the Kindle is jailbroken. Even then it would require further research and development to make DRM removal possible.