2026-04-10 –, Rookie, Student and Careers Track
Cross domain solutions are the gold standard for bridging air-gapped networks, a classic example being between IT and OT networks. Specialist and often with an eye-watering price tag they are mostly out of reach of security researchers and tinkerers alike, but what if you could build something using the same fundamental principles for the price of a round of drinks?
In this talk we'll take a £10 unmanaged network switch and, using a CH341A programmer, modify its EEPROM to change its behaviour. By configuring port isolation masks we can prevent ports from talking back to one another, creating a firmware defined data diode.
The diode is just the one-way valve; a cross domain solution needs to handle more complicated data flows. This is where we'll spend our remaining £10 on a microcontroller with an ethernet port and just enough firmware to manage a protocol break and some data verification.
Whether you are securing a power plant, or just here to bully cheap silicon into doing your bidding, this talk will demonstrate implementing cross domain fundamentals can be done on a shoestring budget.
Who is this guy?
- Software Engineer of 6 years
- Preacher of Rust 🦀
- Worked in cross domain, electronic warfare and now aerospace
- Rare MG / Rover enthusiast