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Impossible Cryptanalysis and Skipjack (1998)

• tinus_hn 5y ago
  From 1998
  • dang 5y ago
    Added. thanks!
• RcouF1uZ4gsC 5y ago
  > The group presented an attack against 31-round Skipjack that is faster than brute force. Skipjack has 32 rounds, so their attack is just shy of being better than brute force. On the other hand, I can’t imagine that the NSA would field an algorithm with 32 rounds when they could break 31, so I believe that the NSA did not know about this attack. And the cryptanalysts are still working on improving their attack, so it is possible that they will get to 32 rounds. In the 23 years since that was posted, no one has been able to extend that attack to 32 rounds. Rather than being a case of the NSA not knowing about that attack, I feel it is a case of the NSA being so sure of its knowledge of this technique that they released Skipjack with exactly the minimum number of rounds required to resist that attack.