S-box

In cryptography, an S-box (substitution-box) is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext — Shannon's property of confusion.

In general, an S-box takes some number of input bits, m, and transforms them into some number of output bits, n, where n is not necessarily equal to m. An m×n S-box can be implemented as a lookup table with 2^m words of n bits each. Fixed tables are normally used, as in the Data Encryption Standard (DES), but in some ciphers the tables are generated dynamically from the key (e.g. the Blowfish and the Twofish encryption algorithms).

One good example of a fixed table is the S-box from DES (S₅), mapping 6-bit input into a 4-bit output:

Given a 6-bit input, the 4-bit output is found by selecting the row using the outer two bits (the first and last bits), and the column using the inner four bits. For example, an input "011011" has outer bits "01" and inner bits "1101"; the corresponding output would be "1001".

Box

Box (plural boxes) describes a variety of containers and receptacles for permanent use as storage, or for temporary use, often for transporting contents.

Boxes may be made of durable materials such as wood or metal, or of corrugated fiberboard, paperboard, or other non-durable materials. The size may vary from very small (e.g., a matchbox) to the size of a large appliance. A corrugated box is a very common shipping container. When no specific shape is described, a box of rectangular cross-section with all sides flat may be expected, but a box may have a horizontal cross section that is square, elongated, round or oval; sloped or domed top surfaces, or non-vertical sides.

A decorative or storage box may be opened by raising, pulling, sliding or removing the lid, which may be hinged and/or fastened by a catch, clasp, or lock.

Packaging box

Several types of boxes are used in packaging and storage.

Box (disambiguation)

A box is a container or package, often rectangular or cuboid.

Box or boxes may also refer to:

People

Companies

Places in England

Plants

In mathematics

GNOME Boxes

Boxes, also known as GNOME Boxes is an application of the GNOME Desktop Environment, used to access remote or virtual systems.

History and functionality

GNOME Boxes was initially introduced as beta software in GNOME 3.3 (development branch for 3.4) as of Dec 2011, and as a preview release in GNOME 3.4. Its primary functions are as a virtual machine manager, remote desktop client (over VNC), and remote filesystem browser, utilizing the libvirt, libvirt-glib, and libosinfo technologies. This enables the viewing of remote systems and virtual machines on other computers in addition to locally created virtual machines. Boxes possesses the ability to easily create local virtual machines from a standard disk image file, such as an ISO image while requiring minimum user input.

People

Boxes was originally developed by Marc-André Lureau, Zeeshan Ali, Alexander Larsson and Christophe Fergeau and is currently being maintained and developed by Zeeshan Ali.

See also