Code breakers crack GSM cellphone encryption

[Greg Rose]

At 11:43 AM 9/8/2003 -0400, Anton Stiglic wrote:
>I think this is different however.  The recent attack focused on the A5/3
>encryption algorithm, while the work of Lucky, Briceno, Goldberg, Wagner,
>Biryukov, Shamir (and others?) was on A5/1 and A5/2 (and other crypto
>algorithms of GSM, such as COMP128, ...).

No, that's not right. The attack *avoids* A5/3, by making the terminal end 
of the call fall back to A5/2, solving for the key in real time, then 
continuing to use the same key with A5/3.

A5/3 (based on Kasumi, and essentially the same as the WCDMA algorithm 
UEA1) is not in any way compromised by this attack.

Greg.


Greg Rose                                       INTERNET: ggr at qualcomm.com
Qualcomm Australia          VOICE:  +61-2-9817 4188   FAX: +61-2-9817 5199
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