PANEPISTHMIO PATRWN. Melèth kai UlopoÐhsh Epexergast n EidikoÔ SkopoÔ (ASIP) gia Kruptografikèc Efarmogèc se Sust mata Periorismènwn Pìrwn - PDF

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PANEPISTHMIO PATRWN Tm ma Mhqanik n H/U kai Plhroforik c Prìgramma Metaptuqiak n Spoud n Oloklhrwmèna Sust mata UlikoÔ kai LogismikoÔ METAPTUQIAKO DIPLWMA EIDIKEUSHS Melèth kai UlopoÐhsh Epexergast n EidikoÔ

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PANEPISTHMIO PATRWN Tm ma Mhqanik n H/U kai Plhroforik c Prìgramma Metaptuqiak n Spoud n Oloklhrwmèna Sust mata UlikoÔ kai LogismikoÔ METAPTUQIAKO DIPLWMA EIDIKEUSHS Melèth kai UlopoÐhsh Epexergast n EidikoÔ SkopoÔ (ASIP) gia Kruptografikèc Efarmogèc se Sust mata Periorismènwn Pìrwn Iwˆnna TsekoÔra Epiblèpwn kajhght c: Kajhght c KwnstantÐnoc GkoÔthc Exetastik epitrop : Kajhght c Odussèac KoufopaÔlou Kajhght c Dhm trioc Nikolìc Pˆtra, Mˆioc 2010 2 Gia thn paroôsa Diplwmatik ErgasÐa EidÐkeushc sunergˆsthkan oi foreðc: Panepist mio Patr n Epiblèpwn: Kajhght c KwnstantÐnoc GkoÔthc Epiblèpwn: imec Ge rgioc SelÐmhc Acknowledgments This thesis is the result of a collaboration between the University of Patras and imec/holst center, and took place in the facilities of imec/holst center in Eindhoven, The Netherlands. Therefore, I would like to thank both of these instritutes for enabling the realization of this thesis. I would like to thank prof. Constantinos Goutis, my supervisor in the University of Patras, prof. Francky Catthoor from imec Leuven and Jos Huisken from imec/holst center, for giving me the opportunity to conduct my master thesis in a research center. This experience was extremely useful for me, and through it, I gained valuable technical knowledge. Especially, I would like to thank Francky Catthoor for his immeasurable contribution in this thesis and Jos Huisken for his support and useful advices. I would like to express my gratitude to Georgios Selimis, my supervisor in imec/holst center, for the cooperation and guidance throughout this thesis. His knowledge on Cryptography was invaluable and by setting clear goals in every step of this thesis, he played a significant role in the successful realization of it. Finally, I would like to thank the ULP-DSP group as it was always willing to help me with every problem I encountered and every question I had. Specifically, I would like to thank Jos Hulzink for sharing his vast knowledge on processor design and for his help with the Target tools, as well as Ben Busze for his valuable help with the synthesis and place and route processes. i ii ACKNOWLEDGMENTS Abstract The battery driven nature of wireless sensor networks, combined with the need of extended lifetime mandates that energy efficiency is a metric with high priority. In the current thesis we explore and compare the energy dissipation of different processor architectures and how it is associated with performance and area requirements. The processor architectures are differentiated based on the datapath length (16-bit, 32-bit, 64-bit and 128-bit) and the corresponding size of the data memories. Our study focuses on AES algorithm, and the indicated processor architectures support AES forward encryption, CCM (32/64/128), CBC (32/64/128) and CTR common modes of operation. In each processor architecture the instruction set is extended to increase the efficiency of the system. iii iv ABSTRACT EKTETAMENH ELLHNIKH PERILHYH H parakoloôjhsh twn leitourgi n tou anjr pinou s matoc mèsw enìc diktôou asôrmatwn aisjht rwn (WSN), mporeð na epiteuqjeð eðte proskoll ntac touc aisjht rec sthn epifˆneia tou s matoc, eðte emfuteôontˆc touc stouc istoôc tou s matoc. Prokeimènou, h teqnologða twn asôrmatwn aut n diktôwn na gðnei eurèwc apodekt, prèpei na melethjoôn zht mata asfaleðac dedomènwn kai na enswmatwjoôn leitourgðec oi opoðec parèqoun asfˆleia kai ikanopoioôn kˆpoiec basikèc koinwnikèc apait seic. Parèqontac leitourgðec asfaleðac se èna tupikì aisjht ra (kìmbo enìc WSN) auxˆnetai to mègejoc tou progrˆmmatoc, o qrìnoc ektèleshc pou apaiteð o mikroepexergast c gia na epexergasteð ta dedomèna kai h kðnhsh sto asôrmato dðktuo. Autèc oi apait seic paðzoun kurðarqo rìlo sthn katanˆlwsh enèrgeiac, h opoða sundèetai me to qrìno zw c tou aisjht ra, èna krðsimo parˆgonta sthn teqnologða twn WSN. Oi aisjht rec sun jwc leitourgoôn me mpatarðec kai h diˆrkeia zw c thc mpatarðac ephreˆzei makroprìjesma to kìstoc touc. 'Oso ligìtero qrìno diarkeð h mpatarða, tìso suqnìtera qreiˆzetai allag epanafìrtish, gegonìc pou kˆnei ton aisjht ra na eðnai asômforoc gia ton katanalwt allˆ kai gia to peribˆllon. H upost rixh leitourgi n me ulikì (hardware) eðnai gnwst ìti epitaqônei thn epexergasða kai mei nei tic apait seic se enèrgeia. Sunep c h Ôparxh bohjhtikoô ulikoô, eðnai anapìfeukth prokeimènou na kataskeuˆsoume sust mata me qamhlèc apait seic se enèrgeia. Oi epexergastèc eidikoô skopoô (ASIP) [1] perièqoun leitourgikèc monˆdec oi opoðec enswmat nontai sto sônolo entol n thc arqitektonik c kai epitaqônoun èna sugkekrimèno fˆsma efarmog n. Autì èqei san apotèlesma th meðwsh twn energeiakˆ apaithtik n se enèrgeia prosbˆsewn sth mn mh, mèsw thc antikatˆstashc sunìlwn entol n apì ligìterec kai pio apodotikèc entolèc. H prosj kh nèwn entol n sto sônolo entol n tou epexergast, auxˆnei thn epifˆneia olokl rwshc kai thn katanˆlwsh isqôoc. O mikrìteroc ìmwc apaitoômenoc qrìnoc ektèleshc antistajmðzei thn aôxhsh thc katanaliskìmenhc isqôoc kai odhgeð se qamhl katanˆlwsh enèrgeiac. H suneisforˆ aut c thc ergasðac sunoyðzetai sta ex c: ˆ SqedÐash kai ulopoðhsh diaforetik n ASIP arqitektonik n, kaj c kai twn antðstoiqwn algorijmik n ulopoi sewn twn efarmog n tic opoðec meletˆme, oi opoðec eðnai o kruptografikìc algìrijmoc AES [2] kai oi ex c eptˆ leitourgðec asfaleðac (AES-CTR (ref. [3]), AES-CBC-MAC (32/64/128) (ref. [3]) kai AES-CCM (32/64/128) (ref. [4])). v vi ˆ Susqètish thc katanaliskìmenhc enèrgeiac me ˆlla mètra apìdoshc, ìpwc h isqôc kai h epifˆneia olokl rwshc, kai exagwg sumperasmˆtwn gia thn pio energeiakˆ apodotik lôsh gia thn epðteuxh asfaleðac sta WSN. Sth sqetik bibliografða sunantˆme ergasðec pou èqoun stìqo thn enswmˆtwsh asfˆleiac sta asôrmata dðktua aisjht rwn. Sugkekrimèna, upˆrqoun ulopoi seic pou èqoun gðnei apokleistikˆ se ulikì (oloklhrwmèna kukl mata eidikoô skopoô - ASIC ), ulopoi seic se logismikì pou efarmìzontai èpeita se epexergastèc genikoô skopoô kai tèloc ulopoi seic se epexergastèc eidikoô skopoô. Oi ergasðec pou an koun sth pr th kathgorða dðnoun lôseic me mikrì kìstoc se ulikì kai mikr katanˆlwsh isqôoc. Wstìso, den parèqoun euelixða kai dunatìthta gia epèktash. Autì eðnai èna shmantikì meionèkthma kaj c ta prìtupa pou qrhsimopoioôntai s mera stic epikoinwnðec, suqnˆ upìkeintai tropopoi seic kai prosj kec. Sunep c h dunatìthta tropopoðhshc twn uparqìntwn susthmˆtwn me to mikrìtero dunatì kìstoc, eðnai polô shmantik. Sth deôterh kathgorða eðnai gnwstì ìti oi epexergastèc genikoô skopoô parèqoun exairetikˆ megˆlh euelixða, allˆ eðnai kai apaithtikoð se isqô kai enèrgeia. Lìgw twn poll n kai genik n dunatot twn touc, katanal noun megˆlh epifˆneia olokl rwshc kai megˆlo posì isqôoc katˆ th leitourgða touc. H teleutaða kathgorða twn epexergast n eidikoô skopoô sunduˆzei ta pleonekt mata twn dôo prohgoômenwn kathgori n. Oi epexergastèc eidikoô skopoô dðnoun th dunatìthta ston programmatist na orðsei tic dikèc tou entolèc kai to dikì tou datapath to opoðo eðnai beltistopoihmèno gia èna sugkekrimèno fˆsma efarmog n. To apotèlesma aut c thc beltistopoðhshc eðnai uyhlìterh apìdosh kai qamhlìterh katanˆlwsh enèrgeiac. Oi asôrmatec metaforèc dedomènwn pou lambˆnoun q ra sta WSN, kˆnoun epitaktik thn enswmˆtwsh leitourgi n asfaleðac. O kruptografikìc algìrijmoc AES, parèqei kruptogrˆfhsh dedomènwn, allˆ sunduasmènoc me ˆlla prìtupa asfaleðac parèqei epiplèon leitourgðec asfaleðac ìpwc epibebaðwsh thc aujentikìthtac dedomènwn, thc aujentikìthtac tou apostolèa, thc akeraiìthtac dedomènwn kai prostasða ènanti thc l yhc pali n kai epanalambanomènwn dedomènwn. 'Opwc anafèrjhke parapˆnw, se aut thn ergasða meletˆme thn apìdosh twn ex c efarmog n: AES, AES-CTR, AES-CBC-MAC (32/64/128) kai AES-CCM (32/64/128) stic diˆforec ASIP arqitektonikèc. Sth sunèqeia ja perigrafoôn sunoptikˆ oi efarmogèc autèc. O AES (Advanced Encryption Standard) eðnai ènac kruptografikìc algìrijmoc pou èqei egkrijeð apì thn epitrop FIPS (Federal Information Processing Standard), kai apoteleð th basik epilog gia kruptogrˆfhsh, gia èna eurô pedðo efarmog n. EÐnai ènac kruptografikìc algìrijmoc summetrikoô kleidioô me eðsodo (Plaintext) kai èxodo (Ciphertext) m kouc 128 bits, kai me euèlikto m koc kleidioô 128, bits. Sto IEEE [5], kaj c kai se ˆlla diadedomèna prìtupa asôrmatwn epikoinwni n, to kleidð èqei m koc 128 bits, mða epilog thn opoða uiojetoôme se aut thn ergasða. O AES algìrijmoc apoteleðtai apì dôo basikèc leitourgðec, thn Epèktash KleidioÔ kai thn Kruptogrˆfhsh, oi opoðec parousiˆzontai sth sunèqeia. ˆ Epèktash KleidioÔ: To kleidð jewreðtai wc ènac disdiˆstatoc pðnakac me tèsseric seirèc, pou epekteðnetai se mia akoloujða apì kleidiˆ gôrwn, mèsw thc sunˆrthshc vii ScheduleKey(). H sunˆrthsh aut perièqei tic akìloujec epimèrouc sunart seic: H SubWord() antikajistˆ ta tèssera teleutaða bytes enìc kleidioô gôrou me parìmoio trìpo me thn SubBytes() h opoða ja parousiasteð parakˆtw. H RotWord() peristrèfei ta tèssera teleutaða bytes enìc kleidioô gôrou. ˆ Kruptogrˆfhsh: H eðsodoc (Plaintext) jewreðtai wc ènac 4x4 pðnakac pou onomˆzetai Katˆstash. Anˆloga me to mègejoc tou kleidioô, h diadikasða Kruptogrˆfhshc perilambˆnei 10, gôrouc antðstoiqa (sthn perðptws mac 10 gôrouc). Se kˆje gôro mða akoloujða apì metasqhmatismoôc efarmìzetai sthn Katˆstash, kai to apotèlesma eðnai h nèa Katˆstash: O SubBytes() metasqhmatismìc eðnai mia mh-grammik antikatˆstash bytes kai efarmìzetai se kˆje byte thc Katˆstashc qrhsimopoi ntac ènan pðnaka antikatˆstashc (S-box). O ShiftRows() metasqhmatismìc olisjaðnei kuklikˆ ta bytes twn tri n teleutaðwn seir n thc Katˆstashc katˆ diaforetikì arijmì jèsewn. O MixColumns() metasqhmatismìc pollaplasiˆzei tic st lec thc Katˆstashc me èna orismèno polu numo. O AddRoundKey()metasqhmatismìc efarmìzei thn XOR prˆxh anˆmesa sth Katˆstash kai èna kleidð gôrou. H leitourgða metrht AES-CTR parèqei kruptogrˆfhsh/apokruptogrˆfhsh dedomènwn kai prostasða ènanti thc l yhc pali n kai epanalambanomènwn dedomènwn. Autì gðnetai efarmìzontac ton algìrijmo AES se èna sônolo diakrit n metrht n kai efarmìzontac thn prˆxh XOR anˆmesa sta endiˆmesa apotelèsmata kai to Plaintext. H leitourgða AES-CTR parousiˆzetai sto Sq ma 1. Figure 1: H AES-CTR leitourgða asfaleðac (Kruptogrˆfhsh/Apokruptogrˆfhsh). H leitourgða sôndeshc kruptografhmènwn pakètwn me tautìqronh paragwg k dika epibebaðwshc aujentikìthtac AES-CBC-MAC parèqei epibebaðwsh thc aujentikìthtac kai thc akeraiìthtac twn dedomènwn, mèsw thc sôndeshc (sunduasmoô) kruptografhmènwn pakètwn me ta prohgoômena kruptografhmèna pakèta. Anˆloga me to mègejoc tou k dika epibebaðwshc aujentikìthtac (MAC) pou parˆgetai, upˆrqoun treic leitourgðec asfaleðac: AES-CBC-MAC-32/64/128. Sto Sq ma 2 parousiˆzetai h dom thc leitourgðac asfaleðac AES-CBC-MAC. viii Figure 2: H AES-CBC-MAC leitourgða asfaleðac. H leitourgða AES-CCM prokôptei sunduˆzontac tic AES-CTR kai AES-CBC- MAC leitourgðec asfaleðac, kai parèqei kruptogrˆfhsh dedomènwn, prostasða ènanti thc l yhc pali n kai epanalambanomènwn dedomènwn kai epibebaðwsh thc aujentikìthtac kai akeraiìthtac twn dedomènwn. ParomoÐwc me tic AES-CBC-MAC leitourgðec, èqoume epðshc treic leitourgðec: AES-CCM-32/64/128. H leitourgða AES-CCM parousiˆzetai sta Sq mata 3, 4 kai 5. Sugkekrimèna, sta Sq mata 3 kai 4 parathroôme ton trìpo me ton opoðo parˆgetai o k dikac epibebaðwshc (MAC) kai gðnetai h kwdikopoðhsh. En sto sq ma 5 parathroôme ton trìpo dhmiourgðac tou telikoô apotelèsmatoc. Figure 3: Paragwg K dika EpibebaÐwshc Aujentikìthtac. Sth sunèqeia parousiˆzoume tic ulopoihmènec ASIP arqitektonikèc. Oi arqitektonikèc autèc eðnai oi ex c: ˆ 16-bit tupikìc epexergast c, ˆ 16-bit epexergast c me epektamèno sônolo entol n, ˆ 32-bit tupikìc epexergast c, ˆ 32-bit epexergast c me epektamèno sônolo entol n, ix Figure 4: DiadikasÐa Kruptogrˆfhshc. Figure 5: To kruptografhmèno m numa kai h Enswmˆtwsh tou K dika EpibebaÐwshc Aujentikìthtac. ˆ 64-bit epexergast c me epektamèno sônolo entol n kai ˆ 128-bit epexergast c me epektamèno sônolo entol n. Gia touc parapˆnw epexergastèc èqoun ulopoihjeð se C, o AES algìrijmoc kai oi eptˆ leitourgðec asfaleðac AES-CTR, AES-CBC-MAC-32, AES-CBC-MAC-64, AES-CBC- MAC-128, AES-CCM-32, AES-CCM-64 kai AES-CCM-128. Stouc 16-bit epexergastèc èqoun axiologhjeð oi 8-bit ulopoi seic, stouc 32-bit epexergastèc oi 32-bit ulopoi seic, ston 64-bit oi 64-bit ulopoi seic kai ston 128-bit epexergast, oi 128-bit ulopoi seic twn parapˆnw efarmog n. H dom twn epexergast n 16-bit kai 32-bit, eðnai parìmoia kai parousiˆzetai sto Sq ma 6. Se autì to Sq ma parousiˆzoume mìno to datapath twn epexergast n aut n. To control path eðnai apl c morf c. Se ìlouc touc epexergastèc pou parousiˆzoume sthn ergasða aut, h lèxh entol n tou epexergast eðnai 16 bits. O pr toc epexergast c pou anafèroume parapˆnw eðnai ènac tupikìc 16-bit epexergast c pou qrhsimopoi jhke wc bˆsh gia thn ulopoðhsh ìlwn twn ASIP epexergast n. O epexergast c autìc perièqei mða 16-bit mn mh dedomènwn, èna arqeðo 8 kataqwrht n genikoô skopoô kai mða Arijmhtik -Logik monˆda (ALU). H ALU uposthrðzei polô aplèc logikèc kai arijmhtikèc prˆxeic ìpwc XOR, OR, AND, prìsjesh, afaðresh kai olðsjhsh. To mègejoc thc lèxhc entol n kaj c kai thc mn mhc entol n eðnai epðshc 16 bits. H epilog thc qr shc enìc 16-bit epexergast ofeðletai sto gegonìc ìti oi tupikoð epexergastèc qamhl c isqôoc pou qrhsimopoioôntai sta WSN, eðnai 16 bits. x Figure 6: H dom tou datapath twn 16-bit kai 32-bit epexergast n. Sth sunèqeia epekteðnoume ton epexergast autì me entolèc oi opoðec stoqeôoun sth meðwsh twn apaitoômenwn kôklwn rologioô kai twn prosbˆsewn sth mn mh. O k dikac pou ulopoieð tic parapˆnw leitourgðec asfaleðac analôetai gia kˆje epexergast kai anagnwrðzontai ta krðsima tm mata pou perilambˆnei. Wc krðsima tm mata jewroôme ta tm mata pou katanal noun polloôc kôklouc rologioô kai kˆnoun pollèc prosbˆseic sth mn mh qreiˆzontai megˆlo q ro dieujônsewn sth mn mh. Gia tic upì melèth efarmogèc ta krðsima tm mata eðnai oi metasqhmatismoð SubBytes() kai MixColumns() tou kruptografikoô algìrijmou AES. O pr toc metasqhmatismìc anˆloga me ton trìpo pou ulopoieðtai eðte apaiteð polloôc kôklouc rologioô (ulopoðhsh me sunduastik logik ) eðte megˆlo apojhkeutikì q ro sth mn mh kai sunep c pollèc prosbˆseic sth mn mh (ulopoðhsh me pðnaka antikatˆstashc), kai o deôteroc polloôc kôklouc rologioô. Sunep c, oi entolèc pou prosjètoume sto sônolo entol n twn epexergast n èqoun wc pr to stìqo thn antikatˆstash twn apaithtik n aut n entol n, me ˆllec pio apodotikèc entolèc. Sth sunèqeia, meletˆte h ìso to dunatìn kalôterh axiopoðhsh twn kainoôrgiwn entol n ste na mei soume peraitèrw touc kôklouc rologioô pou apaitoôntai gia thn ektèlesh twn leitourgi n asfaleðac. Ston 16-bit epexergast prostèjhkan dôo kainoôriec entolèc, oi sbox kai xtime. H pr th antikajistˆ ton SubBytes() metasqhmatismì ton opoðo ulopoieð me sunduastik logik se ulikì kai h deôterh ulopoieð ton finite field (se peperasmèno pedðo) pollaplasiasmì me to stoiqeðo {02} kai epitaqônei thn ektèlesh tou MixColumns() metasqhmatismoô. O 32-bit epexergast c ulopoieðtai qrhsimopoi ntac wc bˆsh ton 16-bit epexergast. Oi diˆdromoi dedomènwn (buses), oi kataqwrhtèc, h mn mh dedomènwn kai h Arijmhtik - Logik Monˆda epekteðnontai sta 32 bits. Wstìso, prokeimènou na diathrhjeð h aplìthta tou epexergast kai na mhn auxhjeð to ulikì alìgista, diathroôme to mègejoc thc lèxhc entol n kaj c kai thc mn mhc entol n tou epexergast sta 16 bits. Gia ton tupikì 32-bit epexergast grˆfoume ton k dika pou ulopoieð tic upì melèth efarmogèc, gia 32 bits. H ulopoðhsh tou AES basðzetai sth qr sh pènte pinˆkwn antikatˆstashc oi opoðoi enswmat noun th sumperiforˆ twn metasqhmatism n SubBytes() kai MixColumns() kai parousiˆzontai sto biblðo [6]. O metasqhmatismìc ShiftRows() ulopoieðtai mèsw katˆllhlwn anajèsewn, kai h AddRoundKey() efarmìzontac thn prˆxh XOR metaxô thc Katˆstashc kai tou kleidioô gôrou. xi Oi pènte pðnakec antikatˆstashc parousiˆzontai stic Exis seic 1: T e0[x] = S[x] [2, 1, 1, 3] T e1[x] = S[x] [3, 2, 1, 1] T e2[x] = S[x] [1, 3, 2, 1] T e3[x] = S[x] [1, 1, 3, 2] T e4[x] = S[x] [1, 1, 1, 1] (1) ìpou S[x] eðnai o pðnakac antikatˆstashc S-box. Oi tèsseric pr toi pðnakec antikatˆstashc uposthrðzoun thn leitourgða twn metasqhmatism n SubBytes() kai MixColumns() kai qrhsimopoioôntai stouc ennèa pr touc gôrouc tou AES. O pèmptoc pðnakac antikatˆstashc prokôptei apì thn epanˆlhyh tou pðnaka antikatˆstashc S-box, tèsseric forèc. Oi pènte pðnakec antikatˆstashc eðnai apojhkeumènoi sth mn mh dedomènwn, me apotèlesma katˆ thn ektèlesh twn efarmog n asfaleðac, na ekteleðtai ènac megˆloc arijmìc prosbˆsewn sth mn mh. Sunep c, prosjètoume sto sônolo entol n tou 32- bit epexergast mða entol pou antikajistˆ touc pènte pðnakec kai epomènwc touc metasqhmatismoôc SubBytes() kai MixColumns(). H entol aut onomˆzetai sbox mix. Epiplèon prostðjentai oi entolèc byte ex0, byte ex1, byte ex2, byte ex3 oi opoðec se sunduasmì me thn sbox mix ulopoioôn apodotikˆ touc treic metasqhmatismoôc: SubBytes(), MixColumns() kai ShiftRows(). Oi 64-bit kai 128-bit epexergastèc ulopoioôntai me diaforetik mejologða apì touc 16- bit kai 32-bit epexergastèc. O lìgoc eðnai ìti efìson to mègejoc thc lèxhc entol n twn epexergast n eðnai stajerì se 16 bits, oi entolèc pou qrhsimopoioôn ˆmesec timèc, ìpwc h fìrtwsh ˆmesou arijmoô (load immediate value) ja apaitoôsan toulˆqiston pènte kôklouc gia thn ektèlesh touc, sth perðptwsh tou 64-bit epexergast. Sunep c h apìdosh twn epexergast n aut n ja upobajmizìtan se shmantikì bajmì. Sto sq ma 7 parousiˆzetai h dom twn epexergast n 64-bit kai 128-bit. Figure 7: H dom twn datapaths twn 64-bit kai 128-bit epexergast n. xii 'Opwc parathroôme sto Sq ma 7, diathroôme th dom tou arqikoô 16-bit epexergast akèraia, kai prosjètoume dianusmatikèc monˆdec gia thn epexergasða twn dianusmatik n dedomènwn (kruptografikˆ dedomèna). Sugkekrimèna prosjètoume mða dianusmatik mn mh dedomènwn, èna dianusmatikì arqeðo kataqwrht n kai mða dianusmatik leitourgik monˆda h opoða enswmat nei thn leitourgða ìlwn twn dianusmatik n entol n. Lìgw thc Ôparxhc twn dôo diaforetik n datapath stouc 64-bit kai 128-bit epexergastèc, eðnai aparaðthto na enswmat soume th leitourgða entol n gia thn epikoinwnða kai th metaforˆ dedomènwn anˆmesa sta dôo datapaths (16-bit kai 64-bit 128-bit antðstoiqa). Oi entolèc autèc eðnai oi vfill kai vget. Ston 64-bit epexergast prostðjetai h entol sbox mix h opoða ekteleð touc metasqhmatismoôc SubBytes(), MixColumns() kai ShiftRows() gia oqt bytes mèsa se èna kôklo rologioô. EpÐshc prostðjetai h entol shuffle h opoða qreiˆzetai gia thn apodotik qr sh thc sbox mix. O 128-bit epexergast c perièqei mða mìno entol aôxhshc thc apìdoshc twn leitourgi n asfaleðac, thn enc sched. H entol aut lambˆnei sthn eðsodì thc, thn Katˆstash to KleidÐ gôrou kai ekteleð ìlouc touc metasqhmatismoôc tou AES ektìc tou AddRoundKey(). Sth sunèqeia, sta parakˆtw sq mata, sugkrðnontai mìno oi tèsseric epexergastèc pou èqoun epektamèno sônolo entol n. Oi t
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