vann-way compression function

cryptography, rund nischitha dairkhya inputtukale oru nischitha dairkhya auttputtaayi parivartthanam cheiyunna oru pravarthanamaanu vann-way compression function. parivartthanam "vann-way" aanu, athaayath oru prathyeka outtputtu nalkiyaal aaa aouttputtilekku compress cheiyunna inputtukal kanakkaakkunnath budhimuttaanu. vann-way compression functionukal parambaraagatha dattaa compression algorithangalumayi bandhappettathalla, pakaram yadhaartha daattayilekk krithyamaayi (nashtamillaattha compression) allengil ekadesham (nashtamulla compression) vipareethamaakkaam.
udaaharanathinu, cryptographic haash functionukalkullile mercle-dangard nirmmaanatthil vann-way compression functionukal upayogikkunnu.
vann-way compression functionukal palappozhum block saifarukalil ninnaan nirmmichirikkunnathu.
davis-mayer, maatyaas-mayer-oosaas, miyaguchi-praneel (single-block-length compression functionukal), emdisi-2/mayer-skilling, emdisi-4, hairos (double-block-length compression functionukal) ennivayaanu eathenkilum saadhaarana block sifarine vann-way compression functionakki mattunnathinulla chila reethikal. eee reethikal kooduthal vishadamaayi vivarichittundu. (ibm pettant nediya oru haash functionte peru koodiyaanu emdisi-2.)
mattoru reethi reethi (allengil pothuve enbo) aanu, ithu "block saifarukale adisthaanamaakkiyulla uyarnna nirakkulla multy-block-length haash functionaanu", ithu saadhaaranayaayi haash saisil ninnu swathanthramaayi (cheria sthiramaaya overheadil maathram) 1 num 2 num idayil (asymptotic) nirakkukal kaivarikkunnu. eee reethi ithuvare gurutharamaaya suraksha vishakalanangalonnum kanditilla, athinaal ithu shradhaapoorvvam kaikaaryam cheyyanam.
compression.
oru compression function rund nischitha dairkhya inputtukale samyojippikkukayum oru inputtinte athe valuppathilulla orotta nischitha dairkhya outtputtu srishtikkukayum cheiyunnu. compression function oru valia nischitha dairkhya inputtine hraswavum nischitha dairkhyamullathumaaya aouttputtilekku parivartthanam cheiyunnuvennum ithu kaanaan kazhiyum.
udaaharanathinu, "inputt eiii" 128 bittukal aayirikkam, "inputt bii" 128 bittukal aayirikkam, avaa 128 bittukalude orotta aouttputtilekku orumichu compress cheiyunnu. ithu oru 256-bitt inputt 128 bittukalude orotta aouttputtilekku compress cheiyunnathinu thulyamaanu.
chila compression functionukal pakuthiyaayi compress cheiyunnilla, pakaram mattethenkilum gadakathaal compress cheiyunnu. udaaharanathinu, "inputt eiii" 256 bittukalum "inputt bii" 128 bittukalum aakam, avaa 128 bittukalude orotta aouttputtilekku compress cheiyunnu. athaayath, motham 384 inputt bittukal 128 outtputtu bittukalayi compress cheiyunnu.
poornnamaaya himapatham undaakunna reethiyilaan misritham nadathunnathu. athaayath, oro outtputtu bittum oro inputt bittineyum aasrayichirikkunnu.
oru vazhi.
kanakkukoottaan eluppavum ennaal vipareethamaakkaan prayasamullathumaaya oru functionaanu vann-way function. oru vann-way compression function (haash function ennum ariyappedunnu) inipparayunna gunangal undaayirikkanam
haash functionte aouttputtile bittukalude ennamaaya formula 12 ulla ekadesham formula 14 nte oru varkk ardhamaakkunnathinu preemej-resistansilum second preemej-resistansilum "asadhyatha" oraal aagrahikkunnu. ennirunnaalum, prathyekichu randaamathe preemej-resistansinu ithu budhimuttulla oru prasnamaanu.
mercle-dangard nirmmaanam.
cryptographic haash functionukalkullile mercle-dangard nirmmaanathilaanu vann-way compression functionukalude oru saadhaarana upayogam. upayogam, shhaa-1 (kaalaharanapetta), shhaa-2 ennivayulppede ettavum vyaapakamaayi upayogikkunna haash functionukal eee nirmmaanam upayogikkunnu.
oru haash function oru nischitha dairkhya aouttputtilekku ekapaksheeyamaaya dairkhya sandesham prosess cheyyaan kazhiyanam. inputtine thulya valippamulla blokkukalude oru parambarayaayi vibhajikkukayum vann-way compression function upayogichu avayil kramanugathamaayi pravartthikkukayum cheiyunnathiloode ithu nedaanaakum. compression function onnukil haashinginaayi prathyekamaayi roopakalppana cheyyaam allengil oru block sifaril ninnu nirmmikkam. avasaanamaayi prosess cheytha block neelam paadu cheythirikkanam, ithu eee nirmmaanatthinte surakshaykk nirnaayakamaan.
upayogicha function formula _ 18 koottiyidi prathirodhasheshiyullathaanel, length padding (emdi-strengthening ennum vilikkunnu) prayogikkumbol, janmadina vairudhyathekkaal vegathil koottiyidi kandethaan aakramanangalkk kazhiyilla (formula _ 11, formula _ 12 bittukalile block sais aanu). athinaal, mercle-dangard haash nirmmaanam sariyaaya compression function kandethunnathinayi sariyaaya haash function kandethunnathinulla prashnam kuraykkunnu.
randaamathe preemej akramanam (oru sandesha formula nalkumbol oru aakramanakaari formula thripthippeduthunnathina mattoru sandesha formula _ 6 kandethunnu. kelsick snearinum anusarichu time formula _ 23 leeii formula _ 22-sandesha-block sandeshathinaayi ithu cheyyaan kazhiyum. formula _ 25 aayirikkumbol eee aakramanathinte sankeernnatha kuranjathu formula _ 24 ll athunnu, sandeshangal hraswamaakumbol formula _ 14-neey sameepikkunnu.
block saifarukalil ninnulla nirmmaanam.
vann-way compression functionukal palappozhum block saifarukalil ninnaan nirmmichirikkunnathu.
block saifarukal rund nischitha valuppathilulla inputtukal (keeyum plaintextum) edukkukayum inputt plaintexinte athe valuppamulla orotta outtputtu (seifertext) nalkukayum cheiyunnu (vann-way compression functionukal pole).
ennirunnaalum, aadhunika block saifarukal bhaagikamaayi maathramaan. athaayath, oru playin teksttum oru siffer teksttum nalkiyaal playin teksttine siffer textilekku encrypt cheiyunna oru qee kandethunnathu asaadyamaanu. ennaal, oru siffer teksttum oru keeyum nalkiyaal block sifarinte decryption function upayogichu oru anuyojyamaaya playin tekst kandethanakum. athinaal, oru block sifarine vann-way compression functionakki maattaan chila adhika pravartthanangal cherkkendathundu.
davis-mayer, maatyaas-mayer-oosaas, miyaguchi-praneel (single-block-length compression functionukal), emdisi-2, emdisi-4, heros (double-block-length compression functionukal) ennivayaanu eathenkilum saadhaarana block sifarine vann-way compression functionakki mattunnathinulla chila reethikal.
single-block-length compression functionukal adisthaana block siffer prosess cheiyunna athe ennam bittukal outtputtu cheiyunnu. thathfalamaayi, eratta-block-dairkhya compression functionukal bittukalude eratti outtputtu cheiyunnu.
oru block sifarinu 128 bitt enna block sais undengil, otta-block-dairkhya reethikal 128 bitt enna block sais ullathum 128 bitt enna haash srishtikkunnathumaaya oru haash function srishtikkunnu. eratta-block-dairkhya reethikal upayogikkunna block sifarinte block valuppavumayi thaarathamyappeduthumbol haash valuppathinte eratti upayogichu haashukal undaakkunnu. athinaal oru 128-bitt block sifarine 256-bitt haash functionakki maattaan kazhiyum.
eee reethikal pinneedu yadhaartha haash function nirmmikkaan mercle-dangard nirmmaanathinullil upayogikkunnu. eee reethikal kooduthal vishadamaayi vivarichittundu.
oru haash functionaayi vann-way compression function nirmmikkaan oru block siffer upayogikkunnathu saadhaaranayaayi haash functionil prathyekamaayi roopakalppana cheytha vann-way compression function upayogikkunnathinekkaal kurachu mandagathiyilaanu. ariyappedunna ellah surakshita nirmmaanangalum sandeshathinte oro blockinum pradhana sheduling cheiyunnathaanu ithinu kaaranam. oru nischitha qee upayogichu oru block sifarilekku oru kooll maathram cheiyunna oru vann-way compression function nirmmikkunnath asaadhyamaanennu black, cochran, shrimpton enniva theliyichittundu. thiranjeduttha block sifarinte pradhana sheduling valare kanatha pravartthanamallenkil praayogikamaayi nyayamaaya vegatha kaivarikkam.
ennaal, chila sandarbhangalil ithu eluppamaanu, kaaranam oru block sifarinte orotta nadappaakkal oru block sifarinum haash function upayogikkaam. smart cardukal allengil kaarukalilo mattu mesheenukalilo ulla nodukal polulla valare cheria ulchertha sisttangalil coode space labhikkaanum ithinu kazhiyum.
athinaal, haash-rettu allengil rettu oru prathyeka compression functione adisthaanamaakkiyulla oru haash functionte kaaryakshamathayude oru nerkkaazhcha nalkunnu. oru aavarthichulla haash functionte nirakk block siffer pravartthanangalude ennavum aouttputtum thammilulla anupaathathe rooparekhappeduthunnu. kooduthal krithyamaayi paranjaal, inputt formula _ 2-nte prosess cheytha bittukalude ennam, block sifarinte outtputtu bitt-length formula _ 12, eee formula _ 12 outtputtu bittukal nirmmikkunnathin aavashyamaaya block siffer ooppareshan formula _ 29 enniva thammilulla anupaathathe nirakk prathinidheekarikkunnu. saadhaaranayaayi, kurachu block siffer pravartthanangalude upayogam muzhuvan haash functionteyum mothatthilulla mikacha prakadanatthinu kaaranamaakunnu, ennaal ithu abhikaamyamallaatha oru cheria haash-moolyathilekku nayikkunnu. nirakk eee soothravaakyathiloode prakadippikkunnu
soothravaakyam _ 31
thaazhepparayunna vyavasthakalenkilum paalichaal maathrame haash function surakshithamaayi kanakkakkaan kazhiyoo
chuvade avatharippichirikkunna nirmmanangal davis-mayer, matyas-mayer-oosaas, miyaguchi-praneel, heros enniva black boxes vishakalanathin keezhil surakshithamaanennu theliyikkappettittund. chila anumaanangalkk keezhil kandethaan kazhiyunna eathoru aakramanavum janmadina aakramanatheppole thanne phalapradamaanennu kaanikkuka ennathaanu lakshyam. anuyojyamaaya ellah block sifarukalum adangiya oru settil ninnu kramarahithamayi thiranjedukkunna oru block siffer upayogichathayi black boxes model anumaanikkunnu. eee maathrkayil oru aakramanakaarikk eathenkilum blokkukal swathanthramaayi encrypt cheyyaanum decrypt cheyyaanum kazhiyum, pakshe block siffer nadappaakkunnathilekku axus illa. encryption, decryption function enniva oru plaintextum oru keeyo allengil oru seifertextum oru keeyum labhikkuna oraakkilukal prathinidheekarikkunnu. jodiyodu aadyamaayi aavasyappettaal, ooraakkilukal kramarahithamayi thiranjeduttha plaintext allengil seifertext upayogichu prathikarikkunnu. avar iruvarum eee trippilttukalkkayi oru table pankidunnu, chodyathil ninnum anubandha prathikaranatthil ninnum oru jody, randaam thavanayum oru chodyam labhichaal record thirike nalkunnu. thelivinaayi oraakkilukalilekku kramarahithamayi thiranjeduttha chodyangal undaakkunna oru koottiyidi kandethal algoritam undu. eee block siffer (0 mattenthenkilum) prayogikkunna oru compression functionil ninnu nirmmicha haash function ulppedunna oru koottiyidikku rund prathikaranangal kaaranamaakukayaanengil algoritam 1 nalkunnu. algoritam 1 nalkaanulla saadhyatha suraksha nila nirnnayikkunna chodyangalude ennathe aasrayichirikkunnu.
davis-mayer.
davis-mayer single-block-length compression function sandeshathinte oro blockinum (formula _ 32) oru block sifarinte thaakolaayi nalkunnu. ithu encrypt cheyyenda playin tekstaayi munbathe haash moolyam (formula _ 33) nalkunnu. adutha haash moolyam (formula _ 35) srishtikkunnathinu outtputtu seifertext munbathe haash moolyavumaayi (formula _ 33) soard (ω) cheiyunnu. aadya roundil munkaala haash moolyam illaathappol athu sthiramaaya munkootty vyakthamakkiya prarambha moolyam (formula _ 36) upayogikkunnu.
ganithashaasthra notteshanil davis-meyarine ingane vivarikkaam
schemine nirakk undu (k ennathu keysise aanu):
block siffer udaaharanathinu 256-bitt keekal upayogikkukayaanenkil, oro sandesha block (formula _ 32) sandeshathinte 256-bitt bhagamaanu. ore block siffer 128 bittukalude block sais upayogikkukayaanenkil oro roundileyum inputt, outtputtu haash moolyangal 128 bittukalaan.
eee reethiyude vyathiyanangal 32-bitt oppidaatha poornnasamkhyakalil kootticherkkal polulla mattethenkilum group pravartthanavumaayi sorine maattisthaapikkunnu.
davis-mayer nirmmaanatthinte sradheyamaaya oru savisheshatha, adisthaana block siffer poornnamaayum surakshithamaanenkilum, nirmmaanathinaayi nischitha pooyintukal kanakkakkaan kazhiyum ennathaanu eathu formulakkum _ 2, oraalkk formula _ 1 nte moolyam kandethaam, athaayath formula _ 42: oraal formula _ 43 sajjamaakkanam. ithu kramarahithamaya pravarthanangalkku theerchayaayum illaatha oru savisheshathayaanu. ithuvare, eee vasthuvine adisthaanamaakkiyulla praayogika akramanangalonnum nadannittilla, ennaal eee "savisheshatha" yekkurichu oraal arinjirikkanam. randaamathe pree-imej aakramanathil sthira-pooyintukal upayogikkaam (oru sandesha formula nalkiyaal, aakramanakaari kelsiyude formula 8 thripthippeduthunnathinna mattoru sandesha formula _ 6 kandethunnu, time formula 22-sandesha-block sandeshathinaayi snear. nirmmaanam sthira pooyintukal (matyas-mayer-oosaas allengil miyaguchi-praneel polullava) eluppathil srishtikkaan anuvadikkunnillenkil eee akramanam formula _ 23 samayathil cheyyaam. rund saahacharyangalilum sankeernnatha formula 11 nuu mukalilaanennum sandeshangal dairkhyameriyathaanenkil formula 14 nuu thaazheyaanennum sandeshangal cheruthaakumbol aakramanathinte sankeernnatha formula 14 lake athunnundennum shradhikkuka.
anuyojyamaaya siffer modelle davis-mayer nirmmaanatthinte suraksha aadyamaayi theliyikkunnathu aarr aanu. vintarnits.
mathyas-mayer-oasas.
matyas-mayer-oosaas single-block-length vann-way compression functione davis-meyarinte duval (vipareeta) aayi kanakkakkaam.
sandeshathinte oro blockinum (formula _ 32) encrypt cheyyenda playin tekstaayi ithu nalkunnu. adutha haash moolyam (formula _ 35) srishtikkunnathinu outtputtu seifertextum athe sandesha blockinoppam (formula _ 32) soard (ω) cheiyunnu. muun haash moolyam (formula _ 33) block sifarinte thaakolaayi nalkunnu. aadya roundil munkaala haash moolyam illaathappol athu sthiramaaya munkootty vyakthamakkiya prarambha moolyam (formula _ 36) upayogikkunnu.
block sifarinu vyathyastha block qee valuppavumundengil haash moolyathinu (formula _ 33) qee aayi upayogikkunnathinu thettaaya valuppamundaakum. sifarinu mattu prathyeka aavashyakathakalum keeyil undayirikkaam. thudarnnu haash moolyam aadyam function formulayiloode nalkunnu _ 59 sifarinte qee aayi parivartthanam/paadu cheiyunnathinaayi.
ganithashaasthra notteshanil mathyas-mayer-oosaasine ingane vivarikkaam
padhathikku thaazhepparayunna nirakkunda
randaamathe preemej akramanam (oru sandesha formula nalkumbol oru aakramanakaari formula 8 thripthippeduthunnathina mattoru sandesha formula 6 kandethunnu) kelsey, snear enniva anusarichu time formula 23 leeii formula 22-sandesha-block sandeshathinaayi cheyyaam. sankeernnatha formula 11 nuu mukalilaanennum sandeshangal dairkhyameriyathaanenkil formula 14 nuu thaazheyaanennum sandeshangal cheruthaakkumbol aakramanathinte sankeernnatha formula 14 lake athumennum shradhikkuka.
miyaguchi-praneel.
miyaguchi-praneel single-block-length vann-way compression function mathyas-mayer-oosaasinte vipuleekritha vakabhedamaanu. shoji miyaguchiyum bart praneelum swathanthramaayi ithu nirddeshichu.
sandeshathinte oro blockinum (formula _ 32) encrypt cheyyenda playin tekstaayi ithu nalkunnu. outtputtu seifertext athe sandesha block (formula _ 32) upayogichu soard (ω) cheyyukayum thudarnnu adutha haash moolyam (formula _ 35) srishtikkunnathinu munbathe haash moolyam (formula _ 33) upayogichu soar cheyyukayum cheiyunnu. muun haash moolyam (formula _ 33) block sifarinte thaakolaayi nalkunnu. aadya roundil munkaala haash moolyam illaathappol athu sthiramaaya munkootty vyakthamakkiya prarambha moolyam (formula _ 36) upayogikkunnu.
block sifarinu vyathyastha block qee valuppavumundengil haash moolyathinu (formula _ 33) qee aayi upayogikkunnathinu thettaaya valuppamundaakum. sifarinu mattu prathyeka aavashyakathakalum keeyil undayirikkaam. thudarnnu haash moolyam aadyam function formulayiloode nalkunnu _ 59 sifarinte qee aayi parivartthanam/paadu cheiyunnathinaayi.
ganithashaasthra notteshanil miyaguchi-praneeline ingane vivarikkaam
padhathikku thaazhepparayunna nirakkunda
formula _ 32, formula _ 33 ennivayude rolukal mattaam, athinaal formula _ 33 pradhana formula _ 32 nuu keezhil encrypt cheythirikkunnu, angane eee reethi pakaram davis-meyarinte vipuleekaranamaakkunnu.
randaamathe preemej akramanam (oru sandesha formula nalkumbol oru aakramanakaari formula 8 thripthippeduthunnathina mattoru sandesha formula 6 kandethunnu) kelsey, snear enniva anusarichu time formula 23 leeii formula 22-sandesha-block sandeshathinaayi cheyyaam. sankeernnatha formula 11 nuu mukalilaanennum sandeshangal dairkhyameriyathaanenkil formula 14 nuu thaazheyaanennum sandeshangal cheruthaakkumbol aakramanathinte sankeernnatha formula 14 lake athumennum shradhikkuka.
hiros.
hairos double-block-length vann-way compression functionil oru block sifar oru kramaparivarthana soothravaakyavum adangiyirikkunnu. ithu 2006 ll shoichi heros nirddeshikkukayum mridul nandiyude oru kruthiye adisthaanamaakkiyullathaanu.
ithu oru block siffer upayogikkunnu, athinte qee length formula _ 93 block length formula _ 12 nekkaal valuthaanu, koodaathe sais formula _ 95 nte oru haash nirmmikkunnu. udaaharanathinu, 192-allengil 256-bitt qee (128-bitt block) ulla eathenkilum aes kaandidettukal.
oro roundum sandesha soothravaakyathinte oru bhagam sweekarikkunnu, athu formula 97 bitt neelamullathaanu, koodaathe formula 99, formula 100 ennee rund formulakal update cheyyaan ithu upayogikkunnu.
aadyam, formula _ 32 oru pradhana formula _ 103 nirmmikkunnathin formula _ 33-maayi samyojippichirikkunnu. thudarnnu rund feedback moolyangalum anusarichu update cheiyunnu
12-bitt moolyathil ekapaksheeyamaaya sthira-pooyint rahita kramappeduthalaanu formula _ 106, saadhaaranayaayi poojyamallaatha ekapaksheeyamaaya sthiramaaya formula _ 109-nuu formula _ 108 aayi nirvachikkappedunnu (ellaam soukaryapradamaaya thiranjeduppaayirikkaam).
oro encryption staanderd davis-mayer nirmmaanavumaayi saamyamullathaan. mattu nirddishta eratta-block-dairkhya skeemukale apekshichu eee skeeminte prayojanam rund encryptionukalum ore qee upayogikkunnu ennathaanu, athinaal pradhana sheduling sramam pankidaan kazhiyum.
anthima outtputtu formula _ 110 aanu. siffer upayogichu sandesham encrypt cheiyunnathumaayi thaarathamyappeduthumbol schemine nirakk formula _ 111 undu.
anuyojyamaaya siffer modalilum heros oru thelivu nalkunnu.
sponch nirmmaanam.
vann-way compression functionukal nirmmikkaan sponch nirmmaanam upayogikkaam.

