Nta ntawm niaj hnub kev sib txuas lus tshuab

Thaum xub thawj siab ib muag, cov tswv yim yuav zoo li synonymous, tab sis lawv muaj txawv kiag li lub ntsiab.

Cipher yog ib txoj kev hloov ntaub ntawv nyob rau hauv thiaj li yuav tiv thaiv tau nws los ntawm nesanktsionnovanih cov neeg siv. Science uas kawm txoj kev thiab cov ntaub ntawv encryption txoj kev hu ua cryptography. Nws yuav tsum tau muab sau tseg uas keeb kwm entrenched nyob rau hauv cryptography ib co txhob txwm ua tub rog cov nqe lus: tus yeeb ncuab nres, code, thiab lwm yam - lawv meej muaj kev cuam tshuam lub ntsiab lus ntawm cov tswv yim. Txawm li cas los, cov tub rog terminology, raws li nyob rau hauv lub sij hawm "code" muaj tsis muaj dab tsi ua nrog rau qhov theoretical cryptography, vim hais tias nyob rau hauv tsis ntev los no xyoo lawm generated cai tshawb xav - ib tug loj scientific teb uas cov kev tshawb fawb thiab kev txoj kev ntawm cov ntaub ntawv tiv thaiv los ntawm qhov tshwm sim ntawm random uas tsis nyob rau hauv kev sib txuas lus raws. Yog li ntawd, hais tias "cai - yog ib hom ntawm encryption" yog ib tug misnomer.

Encoding thiab encryption yog zoo txuas, tab sis txhua tus ntawm cov dab nws muaj nws tus kheej lub hom phiaj. ntaub ntawv coding yog nqa tawm nyob rau hauv thiaj li yuav ua cov ntaub ntawv raws li cov kev cai nyob rau hauv ib daim ntawv haum rau kis tau tus mob tshaj ib tug channel. Cov tub ntxhais ntawm txhua encoding system yog cov zauv cim raws li cov ntaubntawv povthawj siv qauv, raws li nyob rau hauv uas ib tug yuav tau ib tus naj npawb ntawm ntau cov lis dej num. Feem ntau, cov lis dej num sawv cev rau cov hlua ntawm binary zeros thiab sawv daws yuav (xws cov ntaubntawv povthawj siv yog tej yam ntuj tso los siv thaum kis thiab khaws cia cov ntaub ntawv rau computers).

cov ntaub ntawv encryption - ib txoj kev hloov ntaub ntawv rau cov kabmob AI tiv thaiv tawm tsam tsis tau tso cai rau siv. Yog li, cov lus yog encrypted thiaj li hais tias nws yuav to taub tsis tau, thiab coded - mus nyob twj ywm ntshiab txawm tias tom qab cov kev hloov ntawm cov kev sib txuas channel, uas yuav muaj cuam tshuam los ntawm cov suab nrov. Coding ntaub ntawv yuav tsum txo lub cim ntawm cov ntawv nyeem nrog ib tug tsawg tus naj npawb ntawm cov cim (ie, coding yuav tsum pom), thiab mus ntes thiab muaj tseeb uas tsis nyob rau hauv kis tau tus mob thiab cia ntawm cov ntaub ntawv (coding yuav tsum txhim kho kom yog).

Yog li ntawd, yog tias koj xav tau kom dhau cov ntaub ntawv nyob rau hauv ib tug tej yam txuas, thiaj li hais tias thaum lub tso zis rau tau txhim khu kev qha daim card ntaub ntawv yuav tsum muab ob lub hloov siab los ntseeg, namely:

- Hloov cov lus ib co xov tooj system (tej zaum sufficiently hloov dua siab tshiab rau hauv ib tug binary system cim, tab sis muaj lwm tus neeg, e.g., binomial, fibonachieva lwm yam);

- Encrypt lus (muaj ib tug ntau yam ntawm encryption txoj kev, txij thaum lub lag luam ntawm cov lis dej num nce mus txog ancient sij hawm);

- Tau txais encrypted lus yuav tsum tau kho thiaj li mus tso zis ib cov lus yuav uniquely decoded;

- txiav suab ntawm cov lus yuav tsum paub thiab muaj tseeb uas tsis tshwm sim thaum lub sij hawm kis tau tus mob ntawm ib cov lus;

- decrypt cov lus raws li cov encryption nqa tawm (rau cov uas sender thiab receiver yuav tsum xub pom zoo encryption txoj kev). Raws li ib tug txoj cai, txoj kev ua no muaj ib tug general txoj kev, thiab lub "qhov tseem ceeb". Qhov tseem ceeb yog lub teeb ntawm cov ntaub ntawv defining cov kev hloov dua siab tshiab ntawm tus plurality ntawm cipher transformation;

- Tau txais lus hloov lwm lub tsev ntawm lub tau xov tooj system mus rau tus thawj.

Yog li, cov kev tiv thaiv thiab yog kis tau tus mob ntawm cov ntaub ntawv yuav tsum tau ib tug ntau ntawm kev rau siab. Niaj hnub no, ib tug haib computer technology zoo heev simplifies tus txheej txheem no, tab sis nws tsis yog ib txwm tau mus decrypt cov lus, tshwj xeeb tshaj yog yog hais tias tus yuam sij yog tsis paub hais tias nrog kev pab los ntawm technology. Vim lub obstacles nyob rau hauv raws ntawm cov ntaub ntawv tej zaum yuav distorted, yog li siv xws coding hom kev kawm uas yuav ntes thiab kho qhov yuam kev.

Yog li ntawd, ntau tshaj ib tug kev sib txuas lus channel kis lus. Cov lus tau txais yog soj ntsuam txog kev parity ntawm tus xov tooj ntawm chav nyob: yog hais tias lub xov tooj yog txawm units uas ua rau lub assumption tias muaj cov tsis yuam kev, thiab thaum seev suab tsis kam lees yuav lub xeem zauv. Yog hais tias cov xov tooj ntawm chav nyob yog khib, ib cov lus xa nrog kom raug. Lub disadvantage ntawm no txoj kev yog hais tias nws tso cai rau koj mus rau tsuas ntes tsis tsis muaj kev kho lawv, thaum lub repetition code yog tsis tsuas detects tab sis kuj kho kom raug.

Yog li, txhua yam ntawm cov nram no txoj kev ntawm coding nws muaj nws drawbacks, txawm li cas los, cov kev ua si zoo kawg thiab tseem ceeb nyob rau hauv coding kev tshawb xav thiab yog lub hauv paus ntawm lub tsev ib tug ntau zoo meej lis dej num. Nyob rau hauv peb lub sij hawm, lub Hamming cov lis dej num yog siv, Nagoya, Reed -Myullera, Hadamard, thiab lwm yam ..

Kuj ciphers yuav ua li cas los tiv thaiv ntaub ntawv los ntawm tsis tau tso cai nkag tau txhais tau tias muaj ntau ntau txoj kev los ntawm cov uas koj yuav cais ciphers. Feem ntau, qhov yooj yim kev faib yog suav tias yog:

a) txwv kev siv ciphers;

b) ciphers kev siv ntawm pej xeem tseem ceeb;

c) cov lis dej num-sib koom nrog rau cov private tseem ceeb.

Nyob rau hauv 1963, lub American mathematician Klod Shennon siv tib txoj kev nws tsim kev tshawb fawb cipher lej substantiated tias nyob rau hauv tag nrho cov classical ciphers li raug Cheebtsam yog cov nram qab no txoj kev encryption li cov lis dej num thiab ciphers nws raug tawg ri niab.

NTSIAB cipher dispersion yog redistribute redundancy qhov chaw uas yog nyob rau hauv txawv qhov chaw plaintext. Rau lub hom phiaj no, nrog hloov ntawm ib tug finite nab npawb ntawm cov ntsiab P, uas yog ib tug tsis paub qhov tseem ceeb. Yog li, lub xov tooj uas tau tuav yog sib npaug zos rau P.

Thaum deciphered siv rov qab hloov chaw. Tej encryption, tab sis nws tsis cuam tshuam rau zaus ntawm cov tsiaj ntawv, tab sis nkaum qhov zaus ntawm bigrams, trigrams, thiab lwm yam .. Cov essence ntawm lub cipher nws yog mus rau lub kev sib raug zoo ntawm cov qhov tseem ceeb thiab lub encryption cov ntawv nyeem los ua li ntawd complex li sai tau. Zoo siv cov hloov units ntawm ob peb lub cim ntawm cov lus ntawv, txawm tias nws leads mus rau lub fact tias lub ntsiab yuav ntev npaum li cas.

Lub tsev ib tug niaj hnub cryptology raws li ib tug science yog raws li nyob rau hauv lub totality ntawm qhov tseeb thiab cov tswv yim ntawm kev kawm txog zauv, physics, ntaub ntawv kev tshawb xav , thiab lwm yam .. Txawm li cas los, txawm lub complexity, lub nplua mais ntawm theoretical kev kho cryptology yog dav siv nyob rau hauv txhua txhua hnub lub neej, xws li yas cards, e-mail, bank them nyiaj tshuab, nrog cov kev taw qhia ntawm databases, hluav taws xob pov ntawv tawm suab, thiab lwm yam ..