Key reconstruction from the inner state of RC4
Rekonstrukce klíče šifry RC4 z jejího vnitřního stavu
bakalářská práce (OBHÁJENO)
Zobrazit/ otevřít
Trvalý odkaz
http://hdl.handle.net/20.500.11956/73977Identifikátory
SIS: 173365
Kolekce
- Kvalifikační práce [11190]
Autor
Vedoucí práce
Oponent práce
Drápal, Aleš
Fakulta / součást
Matematicko-fyzikální fakulta
Obor
Matematické metody informační bezpečnosti
Katedra / ústav / klinika
Katedra algebry
Datum obhajoby
9. 9. 2016
Nakladatel
Univerzita Karlova, Matematicko-fyzikální fakultaJazyk
Angličtina
Známka
Výborně
Klíčová slova (česky)
RC4, kryptoanalýza, stavová tabulka, proudová šifra, Key Scheduling AlgorithmKlíčová slova (anglicky)
RC4, Cryptanalysis, State Table, Stream Cipher, Key Scheduling AlgorithmIn the present work we analyse the key scheduling algorithm of the RC4 stream cipher. The internal permutation generated by the algorithm is biased towards the secret key which can be utilized in the key recovery attempts. Multiple sources were combined to provide proven formulae for these biases. We have completed missing proofs, experimentally verified resulting probabilities and created examples to illustrate usage of the biases in key recovery attempts. This together with methods for extracting information about the secret key gives analysis of the key scheduling algorithm. We have also selected an efficient key retrieval algorithm and implemented an improved version which results in better success probabilities of the key recovery. We have also provided a tool for extracting the key from a permutation obtained by the key scheduling algorithm. Powered by TCPDF (www.tcpdf.org)