Investigated decrypting a real Microsoft Store Kindle book (KFX). Found the
content is a loose DRMION container with a sibling .voucher, and the account
key material lives in .kinf2024 — a key store newer than and structurally
different from the .kinf2018 that DeDRM supports (zero "/" record separators;
not a version bump). No DeDRM/community support exists for .kinf2024.
The blocker is the key, not KFX itself: without the account DSN/secret the
voucher (and thus the book) cannot be decrypted or tested. Reverse-engineering
.kinf2024 is novel work outside the "port DeDRM" premise, so per decision the
findings, evidence, and a two-part follow-up plan (KFX engine port + .kinf2024
RE) are captured in docs/kfx2024-decryption-effort.md rather than implemented.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
JMR-devandClaude Opus 4.8
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