Accessing the lower files during an active eCryptfs mount is somewhat like accessing a block device on which ext3 is mounted. The kernel allows it, and it may work (depending on what you do with the data), but it is not a good idea. Q. What kernel options do I need to enable to build eCryptfs? Code maturity level options —> [*] Prompt for development and/or incomplete code/drivers Security options —> Enable access key retention support Cryptographic options —> MD5 digest algorithm AES cipher algorithms File systems —> Miscellaneous filesystems —> eCrypt filesystem layer support (EXPERIMENTAL) Recommended .config options (some options not available in older kernels): CONFIG_EXPERIMENTAL=y CONFIG_KEYS=y CONFIG_CRYPTO=y CONFIG_CRYPTO_ALGAPI=y CONFIG_CRYPTO_BLKCIPHER=y CONFIG_CRYPTO_HASH=y CONFIG_CRYPTO_MANAGER=y CONFIG_CRYPTO_MD5=y CONFIG_CRYPTO_ECB=y CONFIG_CRYPTO_CBC=y CONFIG_CRYPTO_AES=y CONFIG_ECRYPT_FS=m Newer versions of the Linux kernel now have a “Layere
