Hugo Guillaume
Security engineer
Konvu
Hugo Guillaume is a security engineer and researcher. He spent close to three years on offensive and defensive security research in a government national-defense setting, doing vulnerability research and reverse engineering and building automated bug-discovery systems (fuzzing, concolic execution, and reinforcement learning). His work includes published CVEs and open-source releases. He also teaches cybersecurity at a university in France. He currently works on application security at Konvu.
When "Encrypted" Isn't: Protecting On-Device ML Models in Mobile Apps
Session
Ship a model to a phone and you've shipped it to whoever owns the phone. Teams know this, so they encrypt the model on disk and move on. That's not protection. It's a speed bump.
I'll show why, with an SDK I took apart and disclosed: Cambridge Mobile Telematics' SensorFlow, which rides inside insurance apps. Inside is an encrypted PyTorch crash classifier. Its verdict feeds premium pricing and claims, so the model is worth hiding, and the encryption is the whole defense.
I pulled the cleartext model out without rooting a device and without Frida. The method is almost dull, which is the point: emulate the SDK's own native library, libsensorflow.so, in software with a Unicorn harness, and let the app's decryption routine hand me the plaintext in emulator memory. The app unlocks its own secret.