Introducing Shufflecake: plausible deniability for multiple hidden filesystems on Linux

Shufflecake is an open-source Linux tool for creating multiple hidden encrypted volumes providing plausible deniability: each volume is encrypted with separate keys, slices are scattered across the device, and up to 15 nested volumes are supported. The project comprises a device-mapper kernel module (dm-sflc) and a userland management tool, with described initialization, open/close operations, performance characteristics (roughly 2x I/O slowdown vs LUKS), and current limitations; the release is a non-production-ready prototype aimed at protecting whistleblowers, journalists, and activists.