Moore's law suggests that computing power doubles roughly every 18 to 24 months, but even this doubling effect leaves the larger symmetric key lengths currently considered acceptable well out of reach.

Mainstream symmetric ciphers ( such as AES or Twofish ) and collision resistant hash functions ( such as SHA ) are widely conjectured to offer greater security against known quantum computing attacks.

Among symmetric key encryption algorithms, only the one-time pad can be proven to be secure against any adversary-no matter how much computing power is available.

Thus, in order to simply flip through the possible values for a 128-bit symmetric key ( ignoring doing the actual computing to check it ) would theoretically require 2 < sup > 128 </ sup > − 1 bit flips on a conventional processor.

Chip multiprocessors, also known as multi-core computing, involves more than one processor placed on a single chip and can be thought of the most extreme form of tightly-coupled multiprocessing.

SIMD multiprocessing finds wide use in certain domains such as computer simulation, but is of little use in general-purpose desktop and business computing environments.

Deadlock is a common problem in multiprocessing systems, parallel computing and distributed systems, where software and hardware locks are used to handle shared resources and implement process synchronization.

* Asymmetric multiprocessing, a computing term

* Chip-level multiprocessing, see multi-core ( computing )

Cellular multiprocessing is a multiprocessing computing architecture designed initially for Intel central processing units from Unisys, a worldwide information technology consulting services and solutions company.

Unified Parallel C ( UPC ) is an extension of the C programming language designed for high-performance computing on large-scale parallel machines, including those with a common global address space ( SMP and NUMA ) and those with distributed memory ( e. g. clusters ).

Grid computing involves computation in a distributed fashion, which may also involve the aggregation of large-scale cluster computing-based systems.

One common pattern in computing involves the processing of several items, one at a time.

This involves computing buoyancy, ( displacement ) and other hydrostatic properties.

Another form of computer surveillance, known as TEMPEST, involves reading electromagnetic emanations from computing devices in order to extract data from them at distances of hundreds of meters.

Another form of behavioral biometrics, based on affective computing, involves computers recognizing a person's emotional state based on an analysis of their facial expressions, how fast they are talking, the tone and pitch of their voice, their posture, and other behavioral traits.

This form of computer surveillance, known as TEMPEST, involves reading electromagnetic emanations from computing devices in order to extract data from them at distances of hundreds of meters.

The five lemma is often applied to long exact sequences: when computing homology or cohomology of a given object, one typically employs a simpler subobject whose homology / cohomology is known, and arrives at a long exact sequence which involves the unknown homology groups of the original object.

involves arranging the lengths of the sides so that and computing

Fixing involves looking up the reference value on the agreed date, recording, then computing a payment based on the rate.

For example, in RSA blinding involves computing the blinding operation E ( x )

Mobile computing involves mobile communication, mobile hardware, and mobile software.

As with simpler checksum algorithms, the Fletcher checksum involves dividing the binary data word to be protected from errors into short " blocks " of bits and computing the modular sum of those blocks.

The process of filename mangling, in computing, involves a re-writing of the file name for compatibility at the operating system level.

A map is a formula for computing a value of a variable based on its own previous value or values ; a quadratic map is one that involves the previous value raised to the powers one and two ; and a complex map is one in which the variable is a complex number.

The subproblem of computing F ( n − 1 ) can itself be broken down into a subproblem that involves computing F ( n − 2 ).

Another technique involves computing the formula for the planes defined by each subset of three points.

His most recent work involves Internet Suspend / Resume, a hands-free approach to mobile computing that layers virtual machine state on a distributed file system.

Superconducting quantum computing is a promising implementation of quantum information that involves nanofabricated superconducting electrodes coupled through Josephson junctions.

The simplest voting logic in computing systems involves two components: primary and alternate.

These issues of computability and algorithm-order are classic computer-science issues and, in that sense, social computing is again a legitimate " computing " subject, even if it involves flexible collaboration as part of the " hardware ".

The difficulty is that the Schrödinger equation involves a function of a number of coordinates that is exponentially large in the number of particles, and is therefore difficult, if not impossible, to solve even using parallel computing technology in a reasonable amount of time.

The primary advantage of distributed computing is that each node can be purchased as commodity hardware, which, when combined, can produce a similar computing resource as multiprocessor supercomputer, but at a lower cost.

In computing, the MSI protocol-a basic cache-coherence protocol-operates in multiprocessor systems.

In human – computer interaction, computer accessibility ( also known as Accessible computing ) refers to the accessibility of a computer system to all people, regardless of disability or severity of impairment.

This means that the programmer must know a " language " that is effective relative to the target computing agent ( computer / computor ).

A January 15, 1941 story in the Des Moines Register announced the ABC as " an electrical computing machine " with more than 300 vacuum tubes that would " compute complicated algebraic equations " ( but gave no precise technical description of the computer ).

* Benchmark ( computing ), the result of running a computer program to assess performance

Thus, computing includes designing and building hardware and software systems for a wide range of purposes ; processing, structuring, and managing various kinds of information ; doing scientific studies using computers ; making computer systems behave intelligently ; creating and using communications and entertainment media ; finding and gathering information relevant to any particular purpose, and so on.

Enthusiast computing refers to a sub-culture of personal computer users who focus on extremely high-performance computers.

These newer concerns are among the many factors causing researchers to investigate new methods of computing such as the quantum computer, as well as to expand the usage of parallelism and other methods that extend the usefulness of the classical von Neumann model.

For a narrative explaining the overall developments, see the related history of computing hardware and history of computer science.

In computing, memory refers to the physical devices used to store programs ( sequences of instructions ) or data ( e. g. program state information ) on a temporary or permanent basis for use in a computer or other digital electronic device.

Nevertheless, caches have proven themselves in many areas of computing because access patterns in typical computer applications have locality of reference.

More recently, with the advent of personal computing, and the growth of home recording, the term computer music is now sometimes used to describe any music that has been created using computing technology.

Advances in computing power and software for manipulation of digital media have dramatically affected the way computer music is generated and performed.

* Clone ( computing ), a hardware computer made by a third party, such as PC clones or Macintosh clones

The Mouse_ ( computing )# Early_mice | first prototype of a computer mouse, as designed by William English ( computer engineer ) | Bill English from Engelbart's sketches.

Theoretical computer science includes areas of discrete mathematics relevant to computing.

Included within theoretical computer science is the study of algorithms for computing mathematical results.

Distributed computing is a field of computer science that studies distributed systems.

The study of distributed computing became its own branch of computer science in the late 1970s and early 1980s.

In computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device.

* Bus ( computing ), used for connecting components of a computer or communication between computers