{"id":112780,"date":"2024-01-09T21:10:14","date_gmt":"2024-01-09T19:10:14","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/uyazvimost-v-realizacziyah-postkvantovogo-algoritma-shifrovaniya-kyber"},"modified":"2024-01-09T21:10:14","modified_gmt":"2024-01-09T19:10:14","slug":"uyazvimost-v-realizacziyah-postkvantovogo-algoritma-shifrovaniya-kyber","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sq\/blog\/news\/uyazvimost-v-realizacziyah-postkvantovogo-algoritma-shifrovaniya-kyber","title":{"rendered":"Vulnerabilitet n\u00eb implementimet e algoritmit t\u00eb enkriptimit post-kantor Kyber","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

N\u00eb realizimin e algoritmit t\u00eb enkriptimit Kyber, i cili fitoi n\u00eb gar\u00ebn p\u00ebr algoritmat kriptografik\u00eb q\u00eb jan\u00eb t\u00eb q\u00ebndruesh\u00ebm ndaj hakimit nga kompjuter\u00ebt kuantike, u zbuluar nj\u00eb dob\u00ebsi q\u00eb lejon kryerjen e sulmeve p\u00ebrmes kanaleve an\u00ebsore p\u00ebr t\u00eb rikrijuar \u00e7el\u00ebsat sekret\u00eb n\u00eb baz\u00eb t\u00eb matjes s\u00eb koh\u00ebs s\u00eb operacioneve gjat\u00eb dekriptimit t\u00eb tekstit t\u00eb enkriptuar t\u00eb ofruar nga sulmuesi. Problemi prek si implementimin referues t\u00eb mekanizmit t\u00eb inkapsulimit t\u00eb \u00e7el\u00ebsave CRYSTALS-Kyber KEM, ashtu edhe shum\u00eb biblioteka t\u00eb tjera enkriptimi q\u00eb mb\u00ebshtesin Kyber, p\u00ebrfshir\u00eb bibliotek\u00ebn pqcrypto t\u00eb aplikuar n\u00eb mesazherin Signal. <\/p>\n

The essence of the vulnerability, codenamed KyberSlash, lies in the use during the decoding of the division operation message «t = (((t < 1) + KYBER_Q\/2)\/KYBER_Q) & 1;», where the dividend contains a secret value «t» of type «double», and the divisor is the well-known public value KYBER_Q. The problem is that the division operation time is not constant, and in different environments, the number of CPU cycles executed for division depends on the input data. Thus, based on the variations in operation times, one can gain insights into the nature of the data used in the division. <\/p>\n

Daniel Bernstein, nj\u00eb ekspert i njohur n\u00eb fush\u00ebn e kriptografis\u00eb, arriti t\u00eb p\u00ebrgatis\u00eb nj\u00eb demonstrim funksional t\u00eb prov\u00ebs s\u00eb mund\u00ebsis\u00eb p\u00ebr t\u00eb kryer nj\u00eb sulm n\u00eb praktik\u00eb. N\u00eb dy nga tre eksperimentet e kryera, gjat\u00eb ekzekutimit t\u00eb kodit n\u00eb pllak\u00ebn Raspberry Pi 2, u arrit t\u00eb rikrijohej plot\u00ebsisht \u00e7el\u00ebsi privat Kyber-512 n\u00eb baz\u00eb t\u00eb matjes s\u00eb koh\u00ebs s\u00eb dekodimit t\u00eb t\u00eb dh\u00ebnave. Metoda gjithashtu mund t\u00eb adaptohet p\u00ebr \u00e7el\u00ebsat Kyber-768 dhe Kyber-1024. P\u00ebr t\u00eb realizuar me sukses sulmin, \u00ebsht\u00eb e nevojshme q\u00eb tekstet e enkriptuara t\u00eb caktuara nga sulmuesi t\u00eb procesoheshin duke p\u00ebrdorur t\u00eb nj\u00ebjt\u00ebn \u00e7ift \u00e7el\u00ebsash dhe q\u00eb t\u00eb ishte e mundur t\u00eb mathej me sakt\u00ebsi koha e ekzekutimit t\u00eb operacionit. <\/p>\n

N\u00eb disa biblioteka \u00ebsht\u00eb zbuluar nj\u00eb tjet\u00ebr rrjedhje (KyberSlash2), e cila gjithashtu ndodh p\u00ebr shkak t\u00eb p\u00ebrdorimit t\u00eb nj\u00eb vlere sekrete gjat\u00eb kryerjes s\u00eb ndarjes. Diferencat nga varianti i par\u00eb reduktohen n\u00eb thirrjen n\u00eb faz\u00ebn e enkriptimit (n\u00eb funksionet poly_compress dhe polyvec_compress), e jo gjat\u00eb dekryptimit. Megjithat\u00eb, varianti i dyt\u00eb mund t\u00eb jet\u00eb i dobish\u00ebm p\u00ebr nj\u00eb sulm vet\u00ebm n\u00eb rastet kur procedura p\u00ebrdoret n\u00eb operacione t\u00eb rizhvillimit, ku rezultati i tekstin e enkriptuar p\u00ebrb\u00ebn nj\u00eb informacion t\u00eb ndjesh\u00ebm. <\/p>\n

Vulnerabiliteti \u00ebsht\u00eb gjithashtu eliminuar n\u00eb bibliotekat: <\/p>\n