Page 325 - PowerPoint Presentation

KRIPTOLOGIJA
CRYPTOLOGY

Autor: Bojan Babić VII-9 OŠ ,, Nikola Tesla‟‟ Vinĉa
Mentori: Vesna Rajšić, dipl. matematicar i Violeta Komnenović, dipl.matematicar

REZIME

Kriptologija, kao nauka svedskog formata, koja je od njenog samog zaĉetka pomagala ĉoveku u oĉuvanju tajnosti
ili privatnosti, svoj cilj zasniva uz pomoć dve nauke koje je saĉinjavaju: kriptografija i kriptoanaliza. Naziv
kriptologija je grĉkog porekla i sastavljena je od dve reĉi: criptos što znaĉi tajnost i logos što znaĉi nauka.To znaĉi
da se kriptologija moţe doslovno prevesti kao “nauka o tajnosti“. Kriptografija je nauka,odnosno grana kriptologije
ĉiji je zadatak da poruku(otvoreni tekst) prevede u šifrat tako da neprijatelj ne moţe dopreti do njene sadrţine
(sl.1).Ime joj je takoĊe grĉkog porekla,nastalog od dve reĉi:criptos što znaĉi tajnost i grafein što znaĉi pisati ili
opisivati,pa se i ona moţe doslovno prevesti kao “tajnopis“.Cilj kriptografije je da:1.pomogne ljudima u oĉuvanju
tajnosti. 2. da podari poruci imunost na strane upade na nju i izmenu teksta. 3 .pomogne u oĉuvanju jedinstvenosti
indentiteta. Šifrovanje ili enkripcija je jedan od kljuĉnih zadataka kriptografije koji kriptograf treba da obavi.
Proces šifrovanja sadrţi preradu otvorenog teksta kojom on menja oblik i, kao što je malopre navedeno, postaje
imuno na poglede ostalih ljudi, prvenstveno osobe C. Dešifrovanje ili dekripcija je takoĊe jedan od kljuĉnih
zadataka kriptografa,koji mu pomaţe da šifrat vrati na staru poruku tako da moţe videti njenu sadrţinu.Teţina
dešifrovanja varira od logiĉkih zakljuĉaka do posebnih algoritama za dekripciju,što zavisi od vrste šifrata.
Kriptoanaliza je nauka (takoĊe grana kriptologije) koja dešifruje šifrat bez javnog kljuĉa.Njen zadatak je, osim
dešifrovanja teksta, poboljšanje šifrata, odnosno pronalaţenja “ranjivosti“ šifrata.
Napad je kljuĉni zadatak kriptoanalitiĉara.Zapravo, napad je proces dešifrovanja i otkrivanja “fiziĉkih”
nedostataka ,odnosno “ranjivosti“ šifrata.Postoje ĉetiri vrste napada.
Kljuĉne reĉi: kriptografija, kriptoanaliza, Playfairova šifra, Viţnerova šifra, transpozicione šifre.

SUMMARY

Cryptology as world class science, which from its very inception aids in the preservation of man secret or policy,
her‟s goal is based with the help of two sciences which consists of: cryptography and cryptanalysis.
Cryptology name is of Greek origin and is composed of 2 : “criptos” meaning secrecy and “logos” meaning
science.Means that cryptography can be literally translated as "the science of secrecy."
Cryptography is the science or branch of cryptology with the task of message (the plaintext) to translate the
ciphertext so that the enemy can‟t reach its menu.Name it is also of Greek origin, arising from 2 : “criptos ,,
meaning secrecy and what it means to write ‘‟grafein‟‟ or describe, so she can be literally translated as
"cecretnote." The goal of cryptography is to: 1 helping people in maintaining the confidentiality of the message
2.give grant immunity to foreign incursions on it and editing 3.help to preserve the uniqueness of identity
Encryption is one of the key tasks of cryptography which cryptographer should to do.The encryption process
includes processing plaintext that it changes shape and, as mentioned earlier, becoming wealthy in the views of
other people, especially people C.
Deciphering or decryption, is also one of the tasks key‟s cryptographer, who helps him ciphertext back to an old
post so he can see her menu.Decryption‟s power varies from logical conclusions to the specific
algorithmsdencryption, it all depends on the type of cipher text.
Cryptanalysis is the science (also a branch of cryptology) to decrypt the ciphertext without needingkey.Her task, in
addition to improving the ciphertext decryption run lines and finding of "vulnerability" ciphertext.
Attack is a key task cryptanalyst actually attack the decryption process and detect "natural" defects and
"vulnerability"srypt.
Keywords: cryptography, cryptanalysis, Playfair cipher, Transposition ciphers, Vigner cipher.