Provable Security and Privacy Analysis of WPA3’s SAE and SAE-PK Protocol

  • Olga Sanina, TU Darmstadt; Kim Laine, Microsoft

Speakers: Olga Sanina
Host: Kim Laine

SAE and SAE-PK are the core security protocols introduced in the latest Wi-Fi security standard, WPA3, to protect personal networks. SAE-PK extends SAE to prevent the so-called evil twin attacks, in which an attacker with knowledge of the password attempts to impersonate a legitimate access point. This is achieved by using a secret key for a signature, with the corresponding public key fingerprinted into the password. In this talk, we will present a formal security model that captures this intended property and show the guarantees the protocol provides. As part of this, we formalize a cryptographic primitive called randomized fingerprinting and analyze the security guarantees of the password generation and public-key verification algorithms introduced in SAE-PK. We show that SAE-PK is indeed secure against evil twin attacks, but its current design introduces a theoretical vulnerability to offline dictionary attacks. To remedy this, we show that SAE-PK can be modified with minimal changes to fully realize its desired security goals.

Series: Cryptography Talk Series