Tim Geoghegan and J.C. Jones, Internet Security Research Group
Multi-party computation (MPC) has long promised privacy-preserving data aggregation, but practical deployments remain rare. The Distributed Aggregation Protocol (DAP), currently progressing through IETF standardization, changes this narrative. We present Divvi Up, a production deployment of DAP processing billions of contributions from widely-deployed applications including Mozilla Firefox. Unlike research prototypes demonstrating MPC feasibility on small datasets, Divvi Up operates at internet scale with multiple independent aggregation servers performing secure multi-party computation on real user data.
This talk covers the architecture of DAP and demonstrates how modern MPC can move beyond academic proofs-of-concept to provide practical, scalable privacy infrastructure. Attendees will learn about deploying privacy-preserving telemetry in production environments and understand the benefits and challenges of deploying MPC to improve privacy, such as:
- Composing private aggregation with differential privacy
- Computational overhead in clients and browsers
- Tradeoffs between flexibility and privacy
Tim (he/him) is an engineer at the Internet Security Research Group and a co-author of the DAP specification at the IETF. He has worked stints at Apple and Square before leading ISRG's role in COVID-19-era exposure notifications as an early application of secure multi-party computation. At ISRG, Tim builds privacy-preserving infrastructure that operates at internet scale. Beyond the zero-knowledge proofs used in DAP's aggregation functions, his current work includes research into zero-knowledge proof systems for digital identity applications.
J.C. (they/them) is an engineer at the Internet Security Research Group, where they work on Divvi Up, a production deployment of the Distributed Aggregation Protocol for privacy-preserving telemetry. J.C. was part of the original Let's Encrypt launch team and previously led the Cryptography Engineering team at Mozilla, where they co-authored the W3C Web Authentication specification (Passkeys) and built Firefox's CRLite whole-web PKI revocation system. They bring extensive experience scaling cryptographic infrastructure from research concepts to internet-scale production deployments.
author = {Tim Geoghegan and J.C. Jones},
title = {Production {Multi-Party} Computation via the Distributed Aggregation Protocol},
year = {2026},
address = {Santa Clara, CA},
publisher = {USENIX Association},
month = jun
}
