Sinesithakazelo esihlokweni sokungaziwa kuma-cryptocurrencies isikhathi eside futhi sizame ukulandela ukuthuthukiswa kobuchwepheshe kule ndawo. Ezihlokweni zethu sesixoxile kakade ngokuningiliziwe izimiso zokusebenza eMonero, futhi kwenziwa ubuchwepheshe obukhona kulo mkhakha. Kodwa-ke, wonke ama-cryptocurrensets angaziwa namuhla akhelwe kumodeli yedatha ehlongozwe yi-Bitcoin - Ukukhipha Okwenziwa Ngayo Okungasetshenzisiwe (ngemuva kwalokhu i-UTXO). Okwama-blockchain asuselwa ku-akhawunti afana ne-Ethereum, izixazululo ezikhona zokwenza ukungaziwa nokugcinwa kuyimfihlo (isibonelo, noma ) wazama ukuphindaphinda imodeli ye-UTXO kuzinkontileka ezihlakaniphile.
NgoFebhuwari 2019, iqembu labacwaningi abavela eStanford University kanye neVisa Research kukhishwe "I-Zether: Ibheke kubumfihlo emhlabeni wezinkontileka ezihlakaniphile." Ababhali babe ngabokuqala ukuphakamisa indlela yokuqinisekisa ukungaziwa kuma-blockchain asekelwe ku-akhawunti futhi bethule izinguqulo ezimbili zenkontileka ehlakaniphile: eyimfihlo (ukufihla amabhalansi namanani okudlulisa) kanye nokungaziwa (ukufihla umamukeli nomthumeli) ukuthengiselana. Sithola ubuchwepheshe obuhlongozwayo buthakazelisa futhi singathanda ukwabelana ngokuklama kwayo, futhi sikhulume ngokuthi kungani inkinga yokungaziwa kuma-blockchains asekelwe ku-akhawunti ibhekwa njengenzima kakhulu nokuthi ababhali bakwazile ukuyixazulula ngokugcwele.
Mayelana nesakhiwo salawa mamodeli wedatha
Kumodeli ye-UTXO, ukuthengiselana kuqukethe "okokufaka" kanye "nokuphumayo". I-analogue eqondile "yemiphumela" yizikweletu ezisesikhwameni sakho: "okukhiphayo" ngakunye kunehlelo elithile. Uma ukhokha umuntu (wenza umsebenzi) usebenzisa "okuphumayo" okukodwa noma ngaphezulu, lapho eba "okufakwayo" kokuthengiselana, futhi i-blockchain imaka njengokuchithiwe. Kulokhu, umamukeli wenkokhelo yakho (noma wena ngokwakho, uma udinga ushintsho) uthola “okuphumayo” okusanda kukhiqizwa. Lokhu kungamelwa ngohlelo kanje:
Ama-blockchain asuselwa ku-akhawunti akhiwe njenge-akhawunti yakho yasebhange. Babhekana kuphela nenani eliku-akhawunti yakho kanye nenani lokudlulisa. Uma udlulisela inani elithile ku-akhawunti yakho, awushisi noma yikuphi "okuphumayo", inethiwekhi ayidingi ukukhumbula ukuthi yiziphi izinhlamvu zemali ezisetshenzisiwe nokuthi yiziphi ezingakenziwa. Esimeni esilula, ukuqinisekiswa kokwenziwe kwehla ekuhloleni isiginesha yomthumeli kanye nenani kubhalansi yakhe:
Ukuhlaziywa kobuchwepheshe
Okulandelayo, sizokhuluma ngokuthi i-Zether ilifihla kanjani inani lomsebenzi, umamukeli, kanye nomthumeli. Njengoba sichaza izimiso zokusebenza kwayo, sizoqaphela umehluko ezinguqulweni eziyimfihlo nezingaziwa. Njengoba kulula kakhulu ukuqinisekisa ubumfihlo kuma-blockchain asekelwe ku-akhawunti, eminye imikhawulo ebekwe ngokungaziwa ngeke ifaneleke kunguqulo eyimfihlo yobuchwepheshe.
Ukufihla amabhalansi namanani okudlulisa
Uhlelo lokubethela lusetshenziselwa ukubethela ibhalansi nokudlulisa amanani ku-Zether . Isebenza kanje. Lapho u-Alice efuna ukuthumela u-Bob b izinhlamvu zemali ngekheli (ukhiye wayo womphakathi) Y, ukhetha inombolo engahleliwe r futhi ibethela inani:
kuphi C - inani elifihliwe, D - inani elisizayo elidingekayo ukuze kuchazwe leli nani, G - iphoyinti elimisiwe ku-elliptic curve, lapho liphindaphindwa ngokhiye oyimfihlo, ukhiye womphakathi uyatholakala.
Lapho uBob ethola lawa manani, umane awengeze kubhalansi yakhe ebethelwe ngendlela efanayo, yingakho lolu hlelo lulula.
Ngokufanayo, u-Alice ususa amanani afanayo kubhalansi yakhe, kuphela njengoba Y isebenzisa ukhiye wakho womphakathi.
Ukufihla umamukeli nomthumeli
Ukushova "okuphumayo" ku-UTXO kuqale ezinsukwini zokuqala ze-cryptocurrencies futhi kusiza ukufihla umthumeli. Ukwenza lokhu, umthumeli ngokwakhe, lapho enza ukudluliselwa, uqoqa "okukhiphayo" okungahleliwe ku-blockchain futhi ayixube neyakhe. Ngokulandelayo, usayinda “okukhiphayo” ngesiginesha esiyindandatho—indlela yokubhala eyimfihlo emvumela ukuba akholise isiqinisekisi ukuthi izinhlamvu zemali zomthumeli zikhona phakathi “kwemiphumela” ehilelekile. Izinhlamvu zemali ezixubile ngokwazo, yiqiniso, azichithwa.
Nokho, ngeke sikwazi ukukhiqiza okukhiphayo okungelona iqiniso ukuze sifihle umamukeli. Ngakho-ke, ku-UTXO, "okuphumayo" ngakunye kunekheli lalo eliyingqayizivele, futhi lixhunywe nge-cryptographically ekhelini lomamukeli walezi zinhlamvu zemali. Okwamanje, ayikho indlela yokuhlonza ubudlelwano phakathi kwekheli lokuphumayo eliyingqayizivele nekheli lomamukeli ngaphandle kokwazi okhiye balo abayimfihlo.
Kumodeli esekelwe ku-akhawunti, asikwazi ukusebenzisa amakheli esikhathi esisodwa (ngaphandle kwalokho azobe eseyimodeli "yokuphuma"). Ngakho-ke, umamukeli nomthumeli kufanele baxutshwe phakathi kwamanye ama-akhawunti ku-blockchain. Kulesi simo, izinhlamvu zemali ezibethelwe ezingu-0 zidonswa kuma-akhawunti ahlanganisiwe (noma u-0 ayengezwa uma umamukeli exutshiwe), ngaphandle kokushintsha ibhalansi yawo yangempela.
Njengoba bobabili umthumeli nomamukeli behlala benekheli elihlala njalo, kuba nesidingo sokusebenzisa amaqembu afanayo ukuze kuxutshwe lapho kudluliselwa emakhelini afanayo. Kulula ukubheka lokhu ngesibonelo.
Ake sithi u-Alice unquma ukwenza umnikelo enhlanganweni ka-Bob esiza abantulayo, kodwa ukhetha ukuthi ukudluliselwa kuhlale kungaziwa kumuntu obukele. Khona-ke, ukuze azifihle emkhakheni womthumeli, futhi ungena kuma-akhawunti ka-Adamu no-Adele. Futhi ukuze ufihle u-Bob, engeza ama-akhawunti ka-Ben noBill endaweni yomamukeli. Enikela ngokulandelayo, u-Alice wanquma ukubhala u-Alex no-Amanda eduze kwakhe, futhi uBruce noBenjen eduze kukaBob. Kulokhu, lapho kuhlaziywa i-blockchain, kulokhu kuthengiselana okubili kukhona ipheya eyodwa kuphela ephambanayo yabahlanganyeli - u-Alice no-Bob, okwenza lokhu kuthengiselana kungaziwa.
Izinhlanga zokuthengiselana
Njengoba sesishilo, ukufihla ibhalansi yakho kumasistimu asekelwe ku-akhawunti, umsebenzisi ubhala ngemfihlo ibhalansi yakhe kanye nenani lokudlulisa. Ngesikhathi esifanayo, kufanele afakazele ukuthi ibhalansi ku-akhawunti yakhe ihlala ingenayo i-negative. Inkinga ukuthi lapho edala umsebenzi, umsebenzisi wakha ubufakazi mayelana nesimo sakhe samanje se-akhawunti. Kwenzekani uma u-Bob ethumela umsebenzi ku-Alice, futhi wamukelwe ngaphambi kwalowo othunyelwe u-Alice? Khona-ke ukuthengiselana kuka-Alice kuzobhekwa njengokungavumelekile, njengoba ubufakazi bebhalansi bakhiwa ngaphambi kokuba kwamukelwe okwenziwa ngu-Bob.
Isinqumo sokuqala esifika esimweni esinjalo ukumisa i-akhawunti kuze kube yilapho ukuthengiselana kwenziwa. Kodwa le ndlela ayifanele, ngoba ngaphezu kobunzima bokuxazulula inkinga enjalo ohlelweni olusabalalisiwe, ohlelweni olungaziwa ngeke kucace ukuthi i-akhawunti kabani izovimba.
Ukuze kuxazululwe le nkinga, ubuchwepheshe buhlukanisa ukuthengiselana okungenayo nokuphumayo: ukusetshenziswa kwemali kunomphumela osheshayo eshidini lebhalansi, kuyilapho amarisidi enomphumela wokulibaziseka. Ukuze wenze lokhu, umqondo we "epoch" wethulwa - iqembu lamabhulokhi osayizi omisiwe. "Inkathi" yamanje inqunywa ngokuhlukanisa ubude bebhulokhi ngosayizi weqembu. Lapho ucubungula okwenziwayo, inethiwekhi ngokushesha ibuyekeza ibhalansi yomthumeli futhi igcina izimali zomamukeli ethangini lokugcina. Izimali eziqoqiwe zenziwa zitholakale kokhokhelwayo kuphela lapho “inkathi” entsha iqala.
Ngenxa yalokho, umsebenzisi angathumela ukuthengiselana kungakhathaliseki ukuthi imali itholwa kaningi kangakanani (ngokuba ibhalansi yakhe ivumela, kunjalo). Usayizi wenkathi unqunywa ngokusekelwe ekutheni amabhulokhi asakazeka ngokushesha kangakanani kunethiwekhi nokuthi ukuthengiselana kungena ngokushesha kangakanani kubhulokhi.
Lesi sixazululo sisebenza kahle ekudlulisweni okuyimfihlo, kodwa ngokuthengiselana okungaziwa, njengoba sizobona kamuva, kudala izinkinga ezinkulu.
Ukuvikelwa ekuhlaselweni kwe-replay
Kuma-blockchain asuselwa ku-akhawunti, umsebenzi ngamunye usayinwa ukhiye oyimfihlo womthumeli, oqinisekisa isiqinisekisi ukuthi umsebenzi awulungiswanga futhi udalwe umnikazi walo khiye. Kodwa kuthiwani uma umhlaseli obelalele isiteshi sokudlulisela abambe lo mlayezo bese ethumela owesibili ofanayo ncamashi? Umqinisekisi uzoqinisekisa isiginesha yomsebenzi futhi uzoqinisekiswa ngobuqambi bakho, futhi inethiwekhi izosula inani elifanayo kubhalansi yomthumeli futhi.
Lokhu kuhlasela kubizwa ngokuthi ukuhlasela kwe-replay. Kumodeli ye-UTXO, ukuhlaselwa okunjalo akufanelekile, ngoba umhlaseli uzozama ukusebenzisa imiphumela esetshenzisiwe, yona ngokwayo ayivumelekile futhi inqatshelwe inethiwekhi.
Ukuvimbela lokhu ukuthi kungenzeki, inkambu enedatha engahleliwe yakhiwe ekuthengiseni, okubizwa ngokuthi i-nonce noma nje "usawoti". Lapho sithumela kabusha umsebenzi ngosawoti, isiqinisekisi sibheka ukuze sibone ukuthi i-nonce ike yasetshenziswa yini ngaphambili, futhi, uma kungenjalo, ibheka okwenziwayo njengokuvumelekile. Ukuze ungagcini umlando wonke wama-nonces wabasebenzisi ku-blockchain, ngokuvamile ekwenziweni kokuqala kumiswa ngokulingana no-zero, bese kwanda ngokukodwa. Inethiwekhi ingahlola kuphela ukuthi i-nonce yomsebenzi omusha iyahluka kuneyangaphambili ngayinye.
Ohlelweni lokudlulisa igama elingaziwa, inkinga yokuqinisekisa izivumelwano zomsebenzi ziyavela. Asikwazi ukuhlanganisa ngokucacile i-nonce ekhelini lomthumeli, njengoba, ngokusobala, lokhu kwenza ukudluliselwa kungaziwa. Futhi asikwazi ukwengeza eyodwa kumanani awo wonke ama-akhawunti abamba iqhaza, njengoba lokhu kungase kungqubuzane nokunye ukudluliselwa okucutshungulwayo.
Ababhali beZether bahlongoza ukukhiqiza i-nonce cryptographically, kuye ngokuthi "inkathi". Ngokwesibonelo:
kuyinto x ukhiye oyimfihlo womthumeli, futhi I-Gepoch — ijeneretha eyengeziwe yenkathi, etholwe ngokusheshisa iyunithi yezinhlamvu zefomu elithi 'Zether +'. Manje inkinga ibonakala ixazululiwe - asivezi i-nonce yomthumeli futhi asiphazamisi imibono yabahlanganyeli abangabandakanyi. Kodwa le ndlela ibeka umkhawulo ongathi sína: i-akhawunti eyodwa ayikwazi ukuthumela okwenziwayo okungaphezu kokukodwa “ngenkathi” ngayinye. Le nkinga, ngeshwa, isalokhu ingaxazululiwe, futhi njengamanje yenza inguqulo engaziwa ye-Zether, ngokubona kwethu, ingafaneleki neze ukusetshenziswa.
Ubunkimbinkimbi Bobufakazi Bolwazi Olungenalo
Ku-UTXO, umthumeli kufanele afakazele inethiwekhi ukuthi akachithi inani elibi, ngaphandle kwalokho kungenzeka ukukhiqiza izinhlamvu zemali ezintsha emoyeni omncane (kungani lokhu kungenzeka, sibhale kwelinye langaphambilini. ). Futhi futhi usayine "okufakiwe" ngesiginesha yendandatho ukufakazela ukuthi phakathi kwezinhlamvu zemali ezixutshwe kukhona izimali ezingezakhe.
Kunguqulo engaziwa ye-blockchain esekelwe ku-akhawunti, izinkulumo zobufakazi ziyinkimbinkimbi kakhulu. Umthumeli ufakazela ukuthi:
- Inani elithunyelwe liphozithivu;
- Ibhalansi ihlala ingekho embi;
- Umthumeli uwabhale kahle amanani okudlulisa (okuhlanganisa uziro);
- Ibhalansi ebhalansi ishintsha kuphela kumthumeli nomamukeli;
- Umthumeli ungumnikazi wokhiye oyimfihlo we-akhawunti yakhe futhi empeleni usohlwini lwabathumeli (phakathi kwalabo abahilelekile);
- I-Nonce esetshenziswe ekuthengiseni yakhiwe ngendlela efanele.
Ngobufakazi obuyinkimbinkimbi obunjalo, ababhali basebenzisa ingxube (omunye wababhali, ngendlela, wabamba iqhaza ekudalweni kwayo) futhi , ezibizwa ngokuthi ama-Sigma-bullets. Ubufakazi obusemthethweni besitatimende esinjalo kuwumsebenzi onzima kakhulu, futhi ukhawulela kakhulu inani labantu abazimisele ukusebenzisa ubuchwepheshe.
Yini ekugcineni?
Ngokombono wethu, ingxenye ye-Zether eletha ubumfihlo kuma-blockchain asuselwa ku-akhawunti ingasetshenziswa njengamanje. Kodwa okwamanje, inguqulo engaziwa yobuchwepheshe ibeka imingcele engathi sína ekusetshenzisweni kwayo, kanye nobunzima bayo ekusetshenzisweni kwayo. Kodwa-ke, akufanele kwehliswe ukuthi ababhali bakhiphe ezinyangeni ezimbalwa ezedlule, futhi mhlawumbe omunye umuntu uzothola isisombululo sezinkinga ezikhona namuhla. Phela, le yindlela isayensi eyenziwa ngayo.
Source: www.habr.com