Geli (software)

geli is a block device-layer disk encryption system written for FreeBSD, introduced in version 6.0. It utilises the GEOM disk framework. It was designed and implemented by Paweł Jakub Dawidek.

Design details

geli was initially written to protect data on a user's computer in situations of physical theft of hardware, disallowing the thief access to the protected data. This has changed over time with the introduction of optional data authentication/integrity verification.

geli allows the key to consist of several information components (a user entered passphrase, random bits from a file, etc.), permits multiple keys (a user key and a company key, for example) and can attach a provider with a random, one-time key. The user passphrase is strengthened with PKCS#5.

Differences from GBDE

The geli utility is different from gbde in that it offers different features and uses a different scheme for doing cryptographic work. It supports the crypto framework within FreeBSD, allowing hardware cryptographic acceleration if available, as well as supporting more cryptographic algorithms (currently AES, Triple DES, Blowfish and Camellia) and data authentication/integrity verification via MD5, SHA1, RIPEMD160, SHA256, SHA384 or SHA512 as Hash Message Authentication Codes.

Software

Computer software also called a program or simply software is any set of instructions that directs a computer to perform specific tasks or operations. Computer software consists of computer programs, libraries and related non-executable data (such as online documentation or digital media). Computer software is non-tangible, contrasted with computer hardware, which is the physical component of computers. Computer hardware and software require each other and neither can be realistically used without the other.

At the lowest level, executable code consists of machine language instructions specific to an individual processor—typically a central processing unit (CPU). A machine language consists of groups of binary values signifying processor instructions that change the state of the computer from its preceding state. For example, an instruction may change the value stored in a particular storage location in the computer—an effect that is not directly observable to the user. An instruction may also (indirectly) cause something to appear on a display of the computer system—a state change which should be visible to the user. The processor carries out the instructions in the order they are provided, unless it is instructed to "jump" to a different instruction, or interrupted.

Software (novel)

Software is a 1982 cyberpunk science fiction novel written by Rudy Rucker. It won the first Philip K. Dick Award in 1983. The novel is the first book in Rucker's Ware Tetralogy, and was followed by a sequel, Wetware, in 1988.

Plot summary

Software introduces Cobb Anderson as a retired computer scientist who was once tried for treason for figuring out how to give robots artificial intelligence and free will, creating the race of boppers. By 2020, they have created a complex society on the Moon, where the boppers developed because they depend on super-cooled superconducting circuits. In that year, Anderson is a pheezer — a freaky geezer, Rucker's depiction of elderly Baby Boomers — living in poverty in Florida and terrified because he lacks the money to buy a new artificial heart to replace his failing, secondhand one.

As the story begins, Anderson is approached by a robot duplicate of himself who invites him to the Moon to be given immortality. Meanwhile, the series' other main character, Sta-Hi Mooney the 1st — born Stanley Hilary Mooney Jr. — a 25-year-old cab driver and "brainsurfer", is kidnapped by a gang of serial killers known as the Little Kidders who almost eat his brain. When Anderson and Mooney travel to the Moon together at the boppers' expense, they find that these events are closely related: the "immortality" given to Anderson turns out to be having his mind transferred into software via the same brain-destroying technique used by the Little Kidders.

Software (development cooperation)

See also

Further reading