A Formal Analysis of 5G Authentication
This addresses security vulnerabilities in 5G authentication, which is crucial for protecting mobile communications globally, representing a foundational analysis rather than an incremental improvement.
The researchers tackled the security of the 5G AKA protocol by conducting the first comprehensive formal model and automated analysis, finding that some critical security goals are not met under the standard's assumptions and providing provably secure fixes.
Mobile communication networks connect much of the world's population. The security of users' calls, SMSs, and mobile data depends on the guarantees provided by the Authenticated Key Exchange protocols used. For the next-generation network (5G), the 3GPP group has standardized the 5G AKA protocol for this purpose. We provide the first comprehensive formal model of a protocol from the AKA family: 5G AKA. We also extract precise requirements from the 3GPP standards defining 5G and we identify missing security goals. Using the security protocol verification tool Tamarin, we conduct a full, systematic, security evaluation of the model with respect to the 5G security goals. Our automated analysis identifies the minimal security assumptions required for each security goal and we find that some critical security goals are not met, except under additional assumptions missing from the standard. Finally, we make explicit recommendations with provably secure fixes for the attacks and weaknesses we found.