Inside China’s Great Firewall with Jackson Sippe

China's Great Firewall, or GFW, is often spoken about but is rarely understood. It is one of the most sophisticated and opaque censorship systems on the planet, and it shapes how over a billion people interact with the global Internet, influences the design of privacy and proxy tools worldwide, and continues to evolve in ways that challenge researchers, developers, and policymakers alike. Jackson Sipp is a PhD researcher at the University of Colorado Boulder whose work focuses on uncovering how national scale censorship systems operate. Jackson recently helped delete a groundbreaking study analyzing a previously undocumented GFW technique that quietly broke fully encrypted proxy protocols across China for more than a year. In this episode, Jackson joins Gregor Van to discuss how the Great Firewall works at a technical level, the twenty twenty one to twenty twenty three blocking event, the pop count based detection algorithm his team reverse engineered, the cat and mouse ecosystem of censorship circumvention, and what these findings mean for the future of the open Internet. Gregor Vand is a security focused technologist, having previously been a CTO across cybersecurity, cyber insurance, and general software engineering companies. He is based in Singapore and can be found via his profile at van.hk or on LinkedIn. Hello and welcome to Software Engineering Daily. My guest today is Jackson Sipp. Hey. Happy to be here. Yeah. So we're gonna be getting into a pretty interesting topic with Jackson today around what is called the GFW, so the great firewall, and we'll get into what even that is. But also Jackson's done a lot of research into how it operates and actually sort of how it operates through the years because it's been changing as well. So before we get into all that as we like to do, maybe just sort of, Jackson, what is your background? How did you get into this kind of research in the first place? Yeah. Sure. So, yeah, I am currently a PhD student at the University of Colorado, Boulder, and I've been here for about five years now. I'm advised by doctor Eric Wistrow, who's been doing this work for a ways longer than that. And as I first started my PhD, I got involved with an organization called the GFW report that has focused on censorship within China. And so through working with them, I've done a number of different projects sort of exploring the relationship between China and censorship. Awesome. So maybe let's just get into what is I always kinda get the acronym mixed up because I think there should be a c in there somewhere because it's sort of like the great Chinese firewall perhaps. But, yeah, maybe what is the GFW? So the GFW is the great firewall as it's known, tends to refer to the censorship mechanism in China. That acronym has sort of expanded as it's gained popularity. Sometimes people refer to Iran's GFW, so we often refer to it as China's GFW now. And it's …