Filesystem-level encryption

Filesystem-level encryption, often called file or folder encryption, is a form of disk encryption where individual files or directories are encrypted by the file system itself. In Computing, a file system (often also written as filesystem) is a method for storing and organizing Computer files and the data they contain to make This is in contrast to full disk encryption where the entire partition or disk, in which the file system resides, is encrypted. Full disk encryption (or whole disk encryption) is a kind of Disk encryption software or hardware which encrypts every Bit of data

The advantages of filesystem-level encryption include:

flexible file-based key management, so that each file can be and usually is encrypted with a separate encryption key
individual management of encrypted files e. Key management is a term used to describe two different fields (1 Cryptography, and (2 physical key management (or Electronic key management) within building or g. incremental backups of the individual changed files even in encrypted form, rather than backup of the entire encrypted volume
access control can be enforced through the use of public-key cryptography, and
the fact that cryptographic keys are only held in memory while the file that is decrypted by them is held open. Access control is the ability to permit or deny the use of a particular resource by a particular entity Public-key cryptography, also known as asymmetric cryptography, is a form of Cryptography in which the key used to encrypt a message differs from the key In Cryptography, a key is a piece of information (a Parameter) that determines the functional output of a cryptographic algorithm

General-purpose file systems with encryption

Unlike cryptographic file systems or full disk encryption, general-purpose file systems that include filesystem-level encryption do not typically encrypt file system metadata, such as the directory structure, file names, sizes or modification timestamps. Metadata ( meta data, or sometimes metainformation) is "data about data" of any sort in any media This can be problematic if the metadata itself needs to be kept confidential. In other words, if files are stored with identifying file names, anyone who has access to the physical disk can know which documents that are stored on the disk, although not the contents of the documents.

Cryptographic file systems

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 – 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. In Cryptography and Steganography, deniable encryption is encryption that allows its user to deny the fact that he or she encrypted a message s/he actually did encrypt Most modern File systems have methods of administering permissions or access rights to specific users and groups of users

General-purpose file systems with encryption

Cryptographic file systems

See also