image image
sylvain pelissier

Nicolas Oberli & Sylvain Pelissier

Talk Title:

Defeating TLS client authentication using fault attacks


There are several ways to add security into embedded devices, one of which is the use of public-key encryption to protect communications. The state-of-the-art method of doing so is to use client certificates to authenticate the client as well as the server.

During this talk, we will present how certificate authentication works, how mbedTLS implements it and how a single fault attack allows recovering the device private key during the authentication phase. We will also show how to review code when taking fault attacks int account, how to look for potentially vulnerable code and how to test these vulnerabilities on a target device.

Speaker Bio:

Nicolas Oberli works as a security researcher for Kudelski Security in Switzerland. His research focuses on embedded devices and communication protocols. In his spare time, he now spends more time designing CTF challenges than solving them. He is also one of the main developers of the Hydrabus hardware hacking tool and part of the BlackAlps security conference committee.

Sylvain Pelissier is a security expert in the security evaluation laboratory at Kudelski IoT Security. His favorite topics are Cryptography, Fault Attacks and vulnerability research in general. He worked on security of Cryptography algorithms implementations on different platforms as well as on critical code security audits. .