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Second 3G GSM Cipher Cracked

Posted by Soulskill on from the dropping-like-encrypted-flies dept.

Trailrunner7 writes "A group of cryptographers has developed a new attack that has broken Kasumi, the encryption algorithm used to secure traffic on 3G GSM wireless networks. The technique enables them to recover a full key by using a tactic known as a related-key attack, but experts say it is not the end of the world for Kasumi. Kasumi, also known as A5/3, is the standard cipher used to encrypt communications on 3G GSM networks, and it's a modified version of an older algorithm called Misty. In the abstract of their paper, the cryptographers say the attack can be implemented easily on one standard PC. 'In this paper we describe a new type of attack called a sandwich attack, and use it to construct a simple distinguisher for 7 of the 8 rounds of KASUMI with an amazingly high probability of 214. By using this distinguisher and analyzing the single remaining round, we can derive the complete 128 bit key of the full KASUMI by using only 4 related keys, 226 data, 230 bytes of memory, and 232 time. These complexities are so small that we have actually simulated the attack in less than two hours on a single PC, and experimentally verified its correctness and complexity.'"

4 of 57 comments (clear)

  1. Language lesson first... by Asadullah+Ahmad · · Score: 0, Offtopic

    "A group of cryptographers has developed...."

    Shouldn't this be "have"?. I admit English is not my first language, but I think I remember those 3rd grade chapters.

    1. Re:Language lesson first... by Paul+Jakma · · Score: 0, Offtopic

      Yes you're right.

      Collective nouns generally are plural. Some nouns are treated as singular, even when you could consider them as groupings. Where the line lies is somewhat subjective. Wrt group, it's very emphatically a collective noun and there should be very little reason to want to consider it a singular, distinct entity from its constituents.

      Another example are companies. It is acceptable to consider these too as plural collectives, e.g. "My company have developed", or "ACMEs' products" (note the placing of the possessive '), indeed it was the normal usage once upon a time. However, the tendency to treat companies as singular, distinct things is becoming (has become) the norm in British english too. It seems nicer to use the plural to me, as it reinforces the idea that companies are not single-minded entities.

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    2. Re:Language lesson first... by khellendros1984 · · Score: 1, Offtopic

      The British might say "A group of cryptographers have developed". To an American, it sounds more natural as written above. A lot of students of English outside of America are likely to have been taught more British patterns of usage.

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  2. EN_UK and EN_US by Inf0phreak · · Score: 1, Offtopic

    In British English, 'have' is indeed correct. US English is a bit different in this regard IIRC.

    "Arsenal have defeated ..." vs. "Arsenal has defeated ..."

    At least that's how I remember it from over a decade ago.

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