Cryptographic file systems are specialized (not general-purpose) file systems that are specifically designed with encryption and security in mind. They usually encrypt all the data they contain R**; including metadata. Instead of implementing an on-disk format and their own block allocation, these file systems are often layered on top of existing file systems e.g. residing in a directory on a host file system. Many such file systems also offer advanced features, such as deniable encryption, cryptographically secure read-only file system permissions and different views of the directory structure depending on the key or user.
