Claw

A claw is a curved, pointed appendage, found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end of the leg or tarsus for gripping a surface as the creature walks. Crabs', lobsters' and scorpions' pincers, or more formally, their "chelae", are sometimes called claws.

A true claw, (as opposed to a chela) is made of hard protein called keratin. Claws are used to catch and hold prey in carnivorous mammals such as cats and dogs, but may also be used for such purposes as digging, climbing trees, self-defense, and grooming, in those and other species.

Similar appendages that are flat and do not come to a sharp point are called nails instead. Claw-like projections that do not form at the end of digits, but spring from other parts of the foot are properly named spurs.

Claws of animals like tigers, lions, and bears were used in making items such as ornaments, pendants, and brooches.

Claw-free permutation

In mathematical and computer science field of cryptography, a group of three numbers (x,y,z) is said to be a claw of two permutations f₀ and f₁ if

A pair of permutations f₀ and f₁ are said to be claw-free if there is no efficient algorithm for computing a claw.

The terminology claw free was introduced by Goldwasser, Micali, and Rivest in their 1984 paper, "A Paradoxical Solution to the Signature Problem" (and later in a more complete journal paper), where they showed that the existence of claw-free pairs of trapdoor permutations implies the existence of digital signature schemes secure against adaptive chosen-message attack. This construction was later superseded by the construction of digital signatures from any one-way trapdoor permutation. The existence of trapdoor permutations does not by itself imply claw-free permutations exist; however, it has been shown that claw-free permutations do exist if factoring is hard.

The general notion of claw-free permutation (not necessarily trapdoor) was further studied by Ivan Damgård in his PhD thesis The Application of Claw Free Functions in Cryptography (Aarhus University, 1988), where he showed how to construct Collision Resistant Hash Functions from claw-free permutations. The notion of claw-freeness is closely related to that of collision resistance in hash functions. The distinction is that claw-free permutations are pairs of functions in which it is hard to create a collision between them, while a collision-resistant hash function is a single function in which it's hard to find a collision, i.e. a function H is collision resistant if it's hard to find a pair of distinct values x,y such that

Claw (disambiguation)

A claw is a sharp growth at the end of a toe or finger.

Claw or Claws may also refer to:

In entertainment:

In music

Forming

Forming may refer to:

See also

Forming (metalworking)

Forming, or metal forming, is the metalworking process of fashioning metal parts and objects through mechanical deformation; the workpiece is reshaped without adding or removing material, and its mass remains unchanged. Forming operates on the materials science principle of plastic deformation, where the physical shape of a material is permanently deformed.

Characteristics

Metal forming tends to have more uniform characteristics across its subprocesses than its contemporary processes, cutting and joining.

On the industrial scale, forming is characterized by:

Forming processes

Forming processes tend to be typified by differences in effective stresses. These categories and descriptions are highly simplified, since the stresses operating at a local level in any given process are very complex and may involve many varieties of stresses operating simultaneously, or it may involve stresses which change over the course of the operation.

Forming (song)

"Forming" is the debut single by American punk rock band Germs. Released on What?, an independent start-up label, in July 1977, it is regarded as the first true Los Angeles punk record.

Germs, comprising four teenagers, formed not long before the recording of the single: David Bowie–worshipping friends Jan Paul Beahm and George Ruthenberg met Belinda Carlisle and Teresa Ryan while staking out Queen's Freddie Mercury at a Beverly Hills motel and decided to start a band. Vocalist Beahm changed his name to Bobby Pyn (he would soon become better known as Darby Crash), guitarist Ruthenberg became Pat Smear, and bassist Ryan transformed into Lorna Doom. Carlisle dropped out when she came down with mononucleosis and never played a live show with the group. She was replaced as drummer by Becky Barton, redubbed Donna Rhia. The band's all-female rhythm section put them—along with X—in the vanguard of women's participation in early L.A. punk, where they would feature in such acts as Bags, The Controllers, Eyes, and the all-female Go-Go's. "Forming" was the band's first composition, written by Pyn after a few rehearsals in the Ruthenberg family garage.