FerroCrypt encrypts files and folders into a single .fcr file.

Choose how to protect your data:

• Password: use the same password to encrypt and decrypt.
• Key pair: encrypt with a recipient's public key. Decryption requires the matching private key and its password. The app can also create key pairs.

FerroCrypt uses standard, widely reviewed cryptography: XChaCha20-Poly1305 encryption, Argon2id for passwords, X25519 for key pairs, and HKDF and HMAC with SHA3-256. Any change to an encrypted file is detected when you decrypt it. The file format is openly documented, and the source code is published under the GPL-3.0 license.

FerroCrypt runs on Linux, macOS, and Windows, as a desktop app and a command-line tool. A file encrypted on one system decrypts on the others.

Encryption leaves the original files in place. File contents are processed in chunks, so an entire file does not need to fit in memory. A password is processed with 1 GiB of memory for a few seconds, which makes guessing it slow and costly for an attacker.

The app can open files in your home folder. To use files on USB drives and other removable media, run: sudo snap connect ferrocrypt:removable-media