Dictionary

preimage en · NOUN

Etymology

Etymology tree Proto-Indo-European *per- Proto-Indo-European *preh₂- Proto-Indo-European *-i Proto-Indo-European *préh₂i? Proto-Italic *prai Proto-Italic *prai- Latin prae-lbor. Middle English pre- English pre- English image English preimage From pre- + image.

Meanings

1. For a given function, the set of all elements of the domain that are mapped into a given subset of the codomain; (formally) given a function ƒ : X → Y and a subset B ⊆ Y, the set ƒ⁻¹(B) = {x ∈ X : ƒ(x) ∈ B}.
   • Loosely speaking, saying that a function f is one-way implies that given y (in the range of f) it is infeasible to find a preimage of y under f. 2005, Oded Goldreich, Foundations of Cryptography: A Primer, now Publishers, page 24:
   • The preimage of #92;#123;4,9#92;#125; under the function f#58;#92;R#92;rightarrow#92;R#58;f(x)#61;x² is the set #92;#123;-3,-2,#43;2,#43;3#92;#125;.
   • Previously, maps and hypermaps were constructed as the preimages of a segment joining two of the three critical values. 2003, Sergei K. Lando, Alexander K. Zvonkin, Graphs on Surfaces and Their Applications, Springer, page 56:
   • 1967 [Academic Press], Francois Treves, Topological Vector Spaces, Distributions and Kernels, 2006, Dover, page 22, The preimage of a neighborhood U of 0 in E must be a neighborhood of (0,x), since (0,x) is mapped into 0.

Forms

Deriveds

preimage attack

Hyponyms

kernel (set of all elements that map into a given subset of the codomain of a function)

Relateds

image

Synonyms

inverse image (set of all elements that map into a given subset of the codomain of a function)

Translations (13)

es antiimagen (set of all elements that map into a given subset of the codomain of a function) · de Urbild (set of all elements that map into a given subset of the codomain of a function) · es contraimagen (set of all elements that map into a given subset of the codomain of a function) · pl przeciwobraz (set of all elements that map into a given subset of the codomain of a function) · es imagen inversa (set of all elements that map into a given subset of the codomain of a function) · fi alkukuva (set of all elements that map into a given subset of the codomain of a function) · eo kontraŭbildo (set of all elements that map into a given subset of the codomain of a function) · eo malbildo (set of all elements that map into a given subset of the codomain of a function) · cmn 原像 (set of all elements that map into a given subset of the codomain of a function) · fr préimage (set of all elements that map into a given subset of the codomain of a function) · eo prabildo (set of all elements that map into a given subset of the codomain of a function) · fr image réciproque (set of all elements that map into a given subset of the codomain of a function) · pt pré-imagem (set of all elements that map into a given subset of the codomain of a function)