Cell Site Simulators From the Ground Up

IMSI-catchers, also known as cell-site simulators, are devices that let their operators track cell users, interfere with their calls/texts, and mount other privacy-invasive attacks. While research around IMSI-catchers has been gaining traction over the years, there hasn’t been much effort into making the more technical results accessible outside of academia and niche hardware hacking circles. The goal of this talk is to remedy that.

This talk will be a deep technical dive into how cell networks interact with user equipment, the details of how IMSI-catchers exploit their design flaws, what goes into building an IMSI-catcher (hypothetically, of course!), the relationship Canadian & American law enforcement have with these devices, and steps one can take to protect themselves.


Yomna Nasser ,

Yomna likes mathematical cryptography, geometry, and succinct explanations. She used to work at the EFF as a Certbot developer (the popular ACME/Let’s Encrypt client), where she also took part in various cell phone security working groups. She currently spends her time thinking about the intersection of distributed systems and mathematical optimization at Stripe.