substitution attack

См. также в других словарях:

• Substitution cipher — In cryptography, a substitution cipher is a method of encryption by which units of plaintext are replaced with ciphertext according to a regular system; the units may be single letters (the most common), pairs of letters, triplets of letters,… …   Wikipedia

• Substitution reaction — In a substitution reaction, a functional group in a particular chemical compound is replaced by another group.[1][2] In organic chemistry, the electrophilic and nucleophilic substitution reactions are of prime importance. Organic substitution… …   Wikipedia

• Substitution box — In cryptography, a substitution box (or S box) is a basic component of symmetric key algorithms. In block ciphers, they are typically used to obscure the relationship between the plaintext and the ciphertext mdash; Shannon s property of confusion …   Wikipedia

• Electrophilic aromatic substitution — or EAS is an organic reaction in which an atom, usually hydrogen, appended to an aromatic system is replaced by an electrophile. The most important reactions of this type that take place are aromatic nitration, aromatic halogenation, aromatic… …   Wikipedia

• Nucleophilic aromatic substitution — A nucleophilic aromatic substitution is a substitution reaction in organic chemistry in which the nucleophile displaces a good leaving group, such as a halide, on an aromatic ring. There are 6 nucleophilic substitution mechanisms encountered with …   Wikipedia

• Nucleophilic substitution — In organic and inorganic chemistry, nucleophilic substitution is a fundamental class of reactions in which an electron nucleophile selectively bonds with or attacks the positive or partially positive charge of an atom or a group of atoms called… …   Wikipedia

• Penal substitution — is a theory of the atonement within Christian theology, especially associated with the Reformed tradition. It argues that Christ, by his own sacrificial choice, was punished (penalised) in the place of sinners (substitution), thus satisfying the… …   Wikipedia

• Nucleophilic acyl substitution — describes the substitution reaction involving nucleophiles and acyl compounds. Acyl compounds are carboxylic acid derivatives including esters, amides and acid halides. Nucleophiles include anionic reagents such as alkoxide compounds and enolates …   Wikipedia

• ipso-Substitution — Der Ausdruck ipso Substitution wird häufig in Verbindung mit einem speziellen Mechanismus der elektrophilen aromatischen Substitution verwendet. Die Bezeichnung „ipso“ (aus dem Lateinischen für „selbst“) soll zum Ausdruck bringen, dass der… …   Deutsch Wikipedia

• Associative substitution — describes a pathway by which compounds interchange ligands. The terminology is typically applied to coordination and organometallic complexes, but resembles the Sn2 mechanism in organic chemistry. The opposite pathway is dissociative substitution …   Wikipedia

• Polygraphic substitution — A polygraphic substitution is a cipher in which a uniform substitution is performed on blocks of letters. When the length of the block is specifically known, more precise terms are used: for instance, a cipher in which pairs of letters are… …   Wikipedia