International Association
for Cryptologic Research

Protests are an important tool in the fight against authoritarian power structures around the world. Authoritarian governments often respond to a large protest by shutting down the Internet in an attempt to stifle this communication. Smartphone mesh messaging has been considered a promising solution to this problem by academics. Given this research interest, it should be the case that mesh messaging is on the path to deployment to counter Internet shutdowns during large-scale protests. So why hasn't it? In this talk, we try to answer this question. We describe the challenges of mesh messaging in detail, and discuss the shortcomings of prior work. We also present our work, Amigo (https://eprint.iacr.org/2024/1872), which represents a step towards a deployable system. But, more work is needed. During this talk, we will journey deep into the network stack of mesh messaging, and show how improvements to cryptographic constructions may not translate to optimized performance. The goal of this talk is to convince the audience that mesh messaging requires more than just better cryptography to achieve deployment; we need cryptography that is tailored to the low-level challenges of a mesh network.