eCryptfs (enterprise cryptographic filesystem) is a package of disk encryption software for Linux.
Its implementation is a POSIX-compliant[1] filesystem-level encryption layer, aiming to offer functionality similar to that of GnuPG at the operating system level,[2] and has been part of the Linux kernel since version 2.6.19.
The eCryptfs package has been included in Ubuntu since version 9.04 to implement Ubuntu's encrypted home directory feature,[3] but is now deprecated[4] eCryptfs is derived from Erez Zadok's Cryptfs.
[5] It uses a variant of the OpenPGP file format for encrypted data, extended to allow random access, storing cryptographic metadata (including a per-file randomly generated session key) with each individual file.
[2] It also encrypts file and directory names which makes them internally longer (average one third).