---
description: Authenticated time synchronization with Roughtime protocol.
title: Roughtime
image: https://developers.cloudflare.com/og-docs.png
---

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# Roughtime

Last updated Aug 24, 2026|Copy as Markdown|[View as Markdown](https://9a51ac8b.previews.developers.cloudflare.com/time-services/roughtime/index.md)|[Agent setup](https://9a51ac8b.previews.developers.cloudflare.com/agent-setup/)

[Roughtime ↗](https://roughtime.googlesource.com/roughtime) is a simple, flexible, and secure authenticated time protocol developed by Google.

## Background

Endpoints on the Internet often synchronize their clocks using the [Network Time Protocol (NTP)](https://9a51ac8b.previews.developers.cloudflare.com/time-services/ntp/). NTP provides precise synchronization, but is frequently deployed without a means of authentication. This is due to a [combination of issues ↗](https://www.usenix.org/conference/usenixsecurity16/technical-sessions/presentation/dowling).

As a result, a man-in-the-middle attacker can easily influence a victim’s clock. By moving them back in time, the attacker can, for example, force a victim to accept an expired (and possibly compromised) TLS certificate or session ticket.

For many applications, _precise_ network time is not essential. It is sufficient to have _accurate_ time to mitigate these kinds of attacks, such as within 10 seconds of real time. This observation is the primary motivation behind Roughtime.

## Next steps

For more technical details on Roughtime, refer to the [introductory blog post ↗](https://blog.cloudflare.com/roughtime/).

To get started, refer to [Get the Roughtime](https://9a51ac8b.previews.developers.cloudflare.com/time-services/roughtime/usage/). For more practical guidance on using the Roughtime, refer to our [how-to guide](https://9a51ac8b.previews.developers.cloudflare.com/time-services/roughtime/recipes/).

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