rencfs

An encrypted filesystem written in Rust and mounted with FUSE on Linux, letting you create encrypted directories you can safely back up to untrusted cloud storage and sync across devices.

Uses well-known audited AEAD primitives (AES-256-GCM / ChaCha20-Poly1305), guards credentials in memory with mlock, mprotect and zeroize, supports fast parallel seek-able reads & writes, and lets you change password without re-encrypting everything. Usable as a CLI or a library.

It was Rust "crate of the week" in August 2024 — and there's a friendly backlog of good first issues.