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. The paper describing the new attack is not yet public, but the Emergent Chaos blog has a good description of the attack, including an excerpt from the abstract …

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