{"id":34823,"date":"2019-10-31T22:00:35","date_gmt":"2019-10-31T19:00:35","guid":{"rendered":"https:\/\/prohoster.info\/blog\/ispolzovanie-sluchajnogo-orakula-na-primere-loterei\/"},"modified":"2019-10-31T22:00:35","modified_gmt":"2019-10-31T19:00:35","slug":"ispolzovanie-sluchajnogo-orakula-na-primere-loterei","status":"publish","type":"post","link":"https:\/\/prohoster.info\/hr\/blog\/administrirovanie\/ispolzovanie-sluchajnogo-orakula-na-primere-loterei","title":{"rendered":"Kori\u0161tenje slu\u010dajnog orakula na primjeru lutrije","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Jednog jutra nai\u0161ao sam na \u010dlanak o testiranom generatoru slu\u010dajnih brojeva<\/a><\/noindex> na blockchain platformi Waves. <\/p>\n

Cjelokupna slika bila je jasna, ali na\u010din konkretne implementacije nije. Kakvi su to kodovi, potpisi, \u0161to, kamo, za\u0161to?<\/p>\n

Nakon nekoliko konzultacija s autorom orakula, uspjeli smo spojiti logiku izvla\u010denja (implementiranu u PHP-u) s algoritmom za generiranje slu\u010dajnog broja.
\n<\/a><\/noindex><\/p>\n

    \n
  1. Na po\u010detku turnira\/kruga tra\u017eimo od orakula prvi dio koda (R-code).\n

    U tom trenutku nema informacija ni o broju igra\u010da, ni o broju nagradnih mjesta, ni o iznosu nagradnih isplata, pa \u010dak ni o postojanju lutrije. Orakl putem transakcije izdaje osobni slu\u010dajni kod koji se mo\u017ee koristiti samo jednom i samo od strane onoga tko ga je zatra\u017eio. Usput, R-code se mo\u017ee 'nabaviti' (misli se na tro\u0161ak transakcije zahtjeva + naknada orakulu za odgovor, to je otprilike $0.015 po trenutnom te\u010daju, a sam kod se izdaje besplatno) unaprijed nekoliko puta, kako ne bismo kasnije \u010dekali odgovor transakcije. Napravio sam mali redovno dopunjeni buffer u bazi podataka.<\/li>\n

  2. Turnir traje standardno 60 blokova blockchaina Waves platforme, \u0161to je trenutno otprilike 1 sat. Turnir se smatra odr\u017eanim i zatvorenim ako nakon 60 blokova ima najmanje dva kupona, ina\u010de se vrijeme trajanja turnira produ\u017eava za sljede\u0107ih 60 blokova.<\/li>\n
  3. Odmah nakon zatvaranja turnira formiramo i \u0161aljemo datumsku transakciju (za koju tako\u0111er pla\u0107amo proviziju od otprilike $0.005), po potrebi \u2013 nekoliko, koja bilje\u017ei sve uvjete izvla\u010denja i ure\u0111en popis igra\u010da (kupona) iz kojeg trebamo odabrati pobjednike.<\/li>\n
  4. U ovom trenutku ve\u0107 imamo prvi dio koda (R-code) plus ID datum transakcije (TXID). \u0160aljemo ih orakulu na potpis u obliku konkatenacije (R-code + TXID), ponovno pla\u0107amo proviziju + naknadu. Orakl provjerava primljene podatke u vezi s jedinstveno\u0161\u0107u i pripadno\u0161\u0107u, a zatim nam \u0161alje drugi dio koda (S-code) u formatu sha256, koji je polazna to\u010dka za generator slu\u010dajnih brojeva.<\/li>\n
  5. Da bismo dobili slu\u010dajni broj koji \u0107e ozna\u010davati redni broj dobitni\u010dkog kupona, pretvaramo S-kod iz binarnih podataka sha256 u heksadecimalnu (HEX) reprezentaciju. Zatim, iz dobijene HEX string, dobijamo broj. Dobijamo ostatak deljenja dobijenog broja s brojem kupona (all_tickets) i dodajemo 1 kao rezultat (da bismo dobili broj od 1 do all_tickets). Na kraju dobijamo redni broj pobednika.<\/li>\n
  6. Ako prema pravilima \u017erebanja ima vi\u0161e dobitnika, ponavljamo prethodne operacije u broju koji odgovara broju nagradnih mesta. Pri tome svaki put uklanjamo iz liste kupon koji je ve\u0107 pobedio i smanjujemo all_tickets za 1, a umesto S-koda navodimo prethodno dobijeni broj.<\/li>\n<\/ol>\n

    \nRazmotrimo konkretan pravi primer, turnir broj 119:<\/p>\n

    Ukupno 7 kupona (all_tickets)
    \nCena kupona 50 nov\u010di\u0107a (Bet)
    \nIgra\u010dki zbir 10% (Fee)<\/p>\n

    Prema pravilima lutrije, 30% ide u nagrade, tj. u ovom slu\u010daju 2 kupona treba da dobiju nagradu, \u010dija se veli\u010dina ra\u010duna po formuli (Bet * all_tickets - Fee) \/ 2.<\/p>\n

    1. Dobijamo R-kod: RdbAiAhKhveAtR4eyTKq75noMxdcEoxbE6BvojJjM13VE<\/a><\/noindex><\/p>\n

    2. Nakon zatvaranja turnira imamo listu kupona u obliku parova: broj + adresu (adresu nov\u010danika sa koje je izvr\u0161ena uplata za u\u010de\u0161\u0107e u turniru). Prime\u0107ujemo da se adrese mogu ponavljati, to zna\u010di da je jedan u\u010desnik kupio vi\u0161e kupona na jednom turniru, \u0161to nije zabranjeno pravilima.<\/p>\n

    Poslali smo datum transakcije: 82JTMzhHM5xEA2fQ9Qscd5QAJU3DAd8nShLjdVHTer5S<\/a><\/noindex><\/p>\n

    3. Zatra\u017eili smo S-kod: FTF3uRyaa4F2uAyD6z5a3CNbTXbQLc7fSR6CFNVjgZYV<\/a><\/noindex> sa komentarom (R-kod + TXID):
    \nRdbAiAhKhveAtR4eyTKq75noMxdcEoxbE6BvojJjM13VE 82JTMzhHM5xEA2fQ9Qscd5QAJU3DAd8nShLjdVHTer5S<\/p>\n

    4. Dobijamo S-kod: Ri89jHB4UXZDXY6gT1m4LBDXGMTaYzHozMk4nxiuqVXdC<\/a><\/noindex><\/p>\n

    5. Odredili smo pobednike.<\/p>\n

    6. Poslali smo isplate<\/a><\/noindex><\/p>\n

    Kao rezultat imamo u blok\u010dejnu korak-po-korak bele\u017eenje procesa \u017erebanja nagrada s mogu\u0107no\u0161\u0107u da ga proverimo u bilo kojem trenutku. Manipulacija rezultatima od strane organizatora gotovo je nemogu\u0107a, barem ne\u0107e biti mogu\u0107e to u\u010diniti neprimetno.<\/p>\n

    odredite pobjednika br. 1\n\nSve_karte:\nIndeks: 1 Karte:139\nIndeks: 2 Karte:141\nIndeks: 3 Karte:143\nIndeks: 4 Karte:145\nIndeks: 5 Karte:147\nIndeks: 6 Karte:149\nIndeks: 7 Karte:151\n\n1. bin -> hex ( bin2hex(sha256(S-kod)) ): Ri89jHB4UXZDXY6gT1m4LBDXGMTaYzHozMk4nxiuqVXdC -> 0xdaf5802953dcb27f89972e38e8900b898733f6a613e6e1c6c5491362c1832596\n\n2. hex -> gmp broj: 0xdaf5802953dcb27f89972e38e8900b898733f6a613e6e1c6c5491362c1832596 -> 99037963059744689166154019807924045947962565922868104113173478160267437352342\n\n3. gmp -> modulo (mod=7): 99037963059744689166154019807924045947962565922868104113173478160267437352342 -> 4\n\n4. modulo -> karta: 4 -> 145\n\nodredite pobjednika br. 2\n\nSve_karte:\n\nIndeks: 1 Karte:139\nIndeks: 2 Karte:141\nIndeks: 3 Karte:143\nIndeks: 4 Karte:147\nIndeks: 5 Karte:149\nIndeks: 6 Karte:151\n\n1. bin -> hex ( bin2hex(sha256(prethodni hex)) ): daf5802953dcb27f89972e38e8900b898733f6a613e6e1c6c5491362c1832596 -> 0x9560e77525e9ea2db92cdb8484dc52046ccafac7c719b8859ff55f0eb92834a0\n2. hex -> gmp broj: 0x9560e77525e9ea2db92cdb8484dc52046ccafac7c719b8859ff55f0eb92834a0 -> 67565829218838067182838043983962684143266386786567427968312120473742580659360\n3. gmp -> modulo (mod=6): 67565829218838067182838043983962684143266386786567427968312120473742580659360 -> 1\n4. modulo -> karta: 1 -> 139\n\nKraj.<\/code><\/pre>\n
    Izvor: habr.com<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"
    \u041a\u0430\u043a-\u0442\u043e \u0443\u0442\u0440\u043e\u043c \u043d\u0430 \u0433\u043b\u0430\u0437\u0430 \u043f\u043e\u043f\u0430\u043b\u0430\u0441\u044c \u0441\u0442\u0430\u0442\u044c\u044f \u043e \u043f\u0440\u043e\u0432\u0435\u0440\u044f\u0435\u043c\u043e\u043c \u0433\u0435\u043d\u0435\u0440\u0430\u0442\u043e\u0440\u0435 \u0441\u043b\u0443\u0447\u0430\u0439\u043d\u044b\u0445 \u0447\u0438\u0441\u0435\u043b \u043d\u0430 \u0431\u043b\u043e\u043a\u0447\u0435\u0439\u043d\u0435 Waves platform. \u041e\u0431\u0449\u0430\u044f \u043a\u0430\u0440\u0442\u0438\u043d\u0430 \u0431\u044b\u043b\u0430 \u043f\u043e\u043d\u044f\u0442\u043d\u0430, \u0430 \u0432\u043e\u0442 \u0441\u043f\u043e\u0441\u043e\u0431 \u043a\u043e\u043d\u043a\u0440\u0435\u0442\u043d\u043e\u0439 \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u2014 \u043d\u0435\u0442. \u041a\u0430\u043a\u0438\u0435-\u0442\u043e \u043a\u043e\u0434\u044b, \u043f\u043e\u0434\u043f\u0438\u0441\u0438, \u0447\u0442\u043e, \u043a\u0443\u0434\u0430, \u0437\u0430\u0447\u0435\u043c? \u041d\u0435\u0441\u043a\u043e\u043b\u044c\u043a\u043e \u043a\u043e\u043d\u0441\u0443\u043b\u044c\u0442\u0430\u0446\u0438\u0439 \u0443 \u0430\u0432\u0442\u043e\u0440\u0430 \u043e\u0440\u0430\u043a\u0443\u043b\u0430, \u0432 \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442\u0435 \u043f\u043e\u043b\u0443\u0447\u0438\u043b\u043e\u0441\u044c \u043e\u0431\u044a\u0435\u0434\u0438\u043d\u0438\u0442\u044c \u043b\u043e\u0433\u0438\u043a\u0443 \u0440\u043e\u0437\u044b\u0433\u0440\u044b\u0448\u0430 (\u0440\u0435\u0430\u043b\u0438\u0437\u043e\u0432\u0430\u043d\u0430 \u043d\u0430 PHP) \u0441 \u0430\u043b\u0433\u043e\u0440\u0438\u0442\u043c\u043e\u043c \u043f\u043e\u043b\u0443\u0447\u0435\u043d\u0438\u044f \u0441\u043b\u0443\u0447\u0430\u0439\u043d\u043e\u0433\u043e \u0447\u0438\u0441\u043b\u0430. \u0412 \u043c\u043e\u043c\u0435\u043d\u0442 \u0441\u0442\u0430\u0440\u0442\u0430 \u0442\u0443\u0440\u043d\u0438\u0440\u0430\/\u0440\u0430\u0443\u043d\u0434\u0430 […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[688],"tags":[],"class_list":["post-34823","post","type-post","status-publish","format-standard","hentry","category-administrirovanie"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\n","aioseo_head_json":{"title":"\ud83e\udd47Kori\u0161tenje slu\u010dajnog orakula na primjeru lutrije | ProHoster","description":"Jednog jutra, nai\u0161ao sam na \u010dlanak o provjerljivom generatoru slu\u010dajnih brojeva na blockchainu Waves platforme.","canonical_url":"https:\/\/prohoster.info\/hr\/blog\/administrirovanie\/ispolzovanie-sluchajnogo-orakula-na-primere-loterei","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"hr_HR","og:site_name":"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b","og:type":"article","og:title":"\ud83e\udd47\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0441\u043b\u0443\u0447\u0430\u0439\u043d\u043e\u0433\u043e \u043e\u0440\u0430\u043a\u0443\u043b\u0430 \u043d\u0430 \u043f\u0440\u0438\u043c\u0435\u0440\u0435 \u043b\u043e\u0442\u0435\u0440\u0435\u0438 | ProHoster","og:description":"\u041a\u0430\u043a-\u0442\u043e \u0443\u0442\u0440\u043e\u043c \u043d\u0430 \u0433\u043b\u0430\u0437\u0430 \u043f\u043e\u043f\u0430\u043b\u0430\u0441\u044c \u0441\u0442\u0430\u0442\u044c\u044f \u043e \u043f\u0440\u043e\u0432\u0435\u0440\u044f\u0435\u043c\u043e\u043c \u0433\u0435\u043d\u0435\u0440\u0430\u0442\u043e\u0440\u0435 \u0441\u043b\u0443\u0447\u0430\u0439\u043d\u044b\u0445 \u0447\u0438\u0441\u0435\u043b \u043d\u0430 \u0431\u043b\u043e\u043a\u0447\u0435\u0439\u043d\u0435 Waves platform.","og:url":"https:\/\/prohoster.info\/hr\/blog\/administrirovanie\/ispolzovanie-sluchajnogo-orakula-na-primere-loterei","og:image":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:secure_url":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:width":350,"og:image:height":350,"article:published_time":"2019-10-31T19:00:35+00:00","article:modified_time":"2019-10-31T19:00:35+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"34823","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":null,"schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"seo_analyzer_scan_date":"2026-01-21 20:44:19","breadcrumb_settings":null,"limit_modified_date":false,"reviewed_by":null,"ai":null,"created":"2021-03-01 02:14:06","updated":"2026-01-21 20:44:19","focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/posts\/34823","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/comments?post=34823"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/posts\/34823\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/media?parent=34823"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/categories?post=34823"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/hr\/wp-json\/wp\/v2\/tags?post=34823"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}