Securing Data Integrity in Modern Overlay Networks: an Integrated Perspective from Theory to Practice

Abstract

In the classic model, data integrity assumes a simple sender-receiver channel where threats are limited and verifications are straightforward. However, the modern Internet has reshaped this paradigm. In an era of viral misinformation, encrypted messaging, and decentralized finance, integrity is no longer about just who sent the data, but what it really means and whether it can be trusted. For instance, can we verify the authenticity of a direct message screenshot? Is Signal's end-to-end encryption truly end-to-end when a central server distributes users' keys? Can decentralized protocols, which have attracted four trillions in capital, sustain trust under attacks that wipe out millions?In response, we present a modern perspective on data integrity across diverse systems, arguing for the need of comprehensive innovations from theory to practice along three axes: cryptographic foundation in which we borrow ideas from theoretical research and develop interesting cryptographic tools, protocol design in which we find and achieve novel application goals, and empirical security analysis in which we critically evaluate deployed systems to understand their strengths and exploit their blind spots.To ground these ideas, we discuss three cases: Cauchyproofs as a batch-updatable vector commitment, an analysis of proxying in TLS oracles revealing subtleties in AEAD context unforgeability, and attacks and improvements on the Tor directory protocol. These case studies illustrate both the fragility and opportunity in today's integrity landscape, and how an integrated approach can help guide us forward.