{"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\/novosti-interneta\/uyazvimost-v-realizacziyah-postkvantovogo-algoritma-shifrovaniya-kyber","title":{"rendered":"Vulnerabilitet n\u00eb implementimet e algoritmit post-kantor t\u00eb enkriptimit Kyber","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
N\u00eb implementimin e algoritmit t\u00eb enkriptimit Kyber, fitues t\u00eb gar\u00ebs s\u00eb algoritmave kriptografik\u00eb t\u00eb q\u00ebndruesh\u00ebm ndaj p\u00ebrpjekjeve me kompjuter\u00eb kuantik\u00eb, \u00ebsht\u00eb zbuluar nj\u00eb dob\u00ebsi q\u00eb lejon kryerjen e sulmeve p\u00ebrmes kanaleve t\u00eb jashtme p\u00ebr t\u00eb rikrijuar \u00e7el\u00ebsat sekret\u00eb duke u bazuar n\u00eb matjen e koh\u00ebs s\u00eb operacioneve gjat\u00eb dekriptimit t\u00eb tekstit t\u00eb enkriptuar t\u00eb paraqitur nga sulmuesi. Problemi preku si implementimin referenc\u00eb t\u00eb mekanizmit t\u00eb inkapsulimit t\u00eb \u00e7el\u00ebsave CRYSTALS-Kyber KEM, ashtu edhe shum\u00eb biblioteka t\u00eb jashtme t\u00eb enkriptimit q\u00eb mb\u00ebshtesin Kyber, duke p\u00ebrfshir\u00eb bibliotek\u00ebn pqcrypto t\u00eb p\u00ebrdorur n\u00eb mesazherin Signal. <\/p>\n
The essence of the vulnerability, codenamed KyberSlash, lies in its use during the decoding of the division operation «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 issue is that the time taken for the division operation is not constant, and in various environments, the number of CPU cycles required for division depends on the input data. Thus, based on the changes in operation time, one can infer the nature of the data used in the division. <\/p>\n
Daniel Bernstein, ekspert i njohur n\u00eb fush\u00ebn e kriptografis\u00eb, arriti t\u00eb p\u00ebrgatis\u00eb nj\u00eb demonstruese funksionale 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 n\u00eb pllakat Raspberry Pi 2 u arrit t\u00eb rikrijohej plot\u00ebsisht \u00e7el\u00ebsi i mbyllur Kyber-512 mbi baz\u00ebn e 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 kryerjen e suksesshme t\u00eb sulmit, \u00ebsht\u00eb e nevojshme q\u00eb teksti i enkriptuar, i paracaktuar nga sulmuesi, t\u00eb p\u00ebrpunoj\u00eb t\u00eb nj\u00ebjt\u00ebn pal\u00eb \u00e7el\u00ebsa dhe q\u00eb t\u00eb jet\u00eb e mundur t\u00eb matet sakt\u00ebsisht koha e ekzekutimit t\u00eb operacionit. <\/p>\n
N\u00eb disa biblioteka \u00ebsht\u00eb zbuluar nj\u00eb rrjedhje tjet\u00ebr (KyberSlash2), e cila gjithashtu ndodh p\u00ebr shkak t\u00eb p\u00ebrdorimit t\u00eb nj\u00eb vler\u00eb sekrete gjat\u00eb kryerjes s\u00eb ndarjes. Diferencat nga versioni i par\u00eb p\u00ebrfshijn\u00eb thirrje n\u00eb faz\u00ebn e enkriptimit (n\u00eb funksionet poly_compress dhe polyvec_compress), dhe jo gjat\u00eb dekriptimit. Megjithat\u00eb, versioni i dyt\u00eb mund t\u00eb jet\u00eb i dobish\u00ebm p\u00ebr sulmin vet\u00ebm n\u00eb rastet e p\u00ebrdorimit t\u00eb procedur\u00ebs n\u00eb operacionet e ri-enkriptimit, n\u00eb t\u00eb cilat rezultati i tekstit t\u00eb enkriptuar konsiderohet konfidencial. <\/p>\n