WhatsApp Key Transparency

Monday, September 11, 2023 - 9:35 am9:50 am

Kevin Lewi, Meta


Earlier this year, WhatsApp announced their plans to launch key transparency for all WhatsApp users. Key transparency solutions help strengthen the guarantee that end-to-end encryption provides to private, personal messaging applications in a transparent manner available to all. In this presentation, we will cover how key transparency works, what the improved end user experience is for those wishing to verify their contacts' public keys, and various deployment challenges and considerations we encountered when building our key transparency system. We also have released an open-source library called Auditable Key Directory (AKD) which we use in our deployment, and can potentially serve as a reference point for others that wish to deploy key transparency in the future.

Kevin Lewi, Meta

Kevin Lewi is a software engineer at Meta. He has worked on the development of the OPAQUE protocol and its integration into WhatsApp's encrypted backups feature. Before joining Meta, he completed his PhD in applied cryptography at Stanford University, advised by Dan Boneh.

@conference {290879,
author = {Kevin Lewi},
title = {{WhatsApp} Key Transparency},
year = {2023},
address = {Santa Clara, CA},
publisher = {USENIX Association},
month = sep

Presentation Video