About Time (WHY2025)

Chaos Computer Club - recent audio-only feed

A shared understanding of what time it is and the rate at which time progresses is essential in many areas of technology from industrial control to broadcast. There are two main ways of synchronizing time between multiple computers, Network Time Protocol (NTP) and Precision Time Protocol (PTP). NTP is sufficient for certificate validation, but when timing is crucial we need PTP. In this talk we will take a deep dive into PTP: what it is, how it works, and various ways to abuse it. In my previous talks about Audio over IP and AV technologies the Precision Time Protocol has come up repeatedly as something that deserves its own talk. PTP has a wider use case which makes it interesting as a target for shenanigans. The talk aims to consolidate several years of experience and research into a concise understanding of this fundamental technology. No prior knowledge about PTP or network time will be assumed. Some familiarity with networking basics will be helpful, but not essential. Warning may contain hacker humor. Licensed to the public under https://creativecommons.org/licenses/by/4.0/ about this event: https://program.why2025.org/why2025/talk/LJ9879/