Sign in. android / kernel / msm / android-7.1.0_r0.2 / . / drivers / md / dm-req-crypt.c. blob: 3257f1bf13efa706b7d630ac3ad9eba9efe4cd92   
How to Encrypt Your Data with dm-crypt | Linode Dec 18, 2018 Removing encryption from recovery - Android Enthusiasts Wiping the data partition simply removes the filesystem header at the beginning of the partition. It doesn't work because on many versions of Android, the LUKS/dm-crypt header is at the end of the filesystem. – Naftuli Kay Sep 5 '16 at 19:59
dm-crypt - Wikipedia
How does Android filesystem encryption work? - Information Android uses dm-crypt for disk encryption, and it is available since Android 3. And as you would know dm-crypt works at block device layer. So storage like YAFFS which works directly at nand flash chip level would not allow you to encrypt. But all other storage (which can be read block by block) can be encrypted.
dm-crypt/Device encryption - ArchWiki
How does Android filesystem encryption work? - Information