Roughtime Server in Beijing

Update 2020-12-10: I have shut this service down.

I run a public Roughtime server on the Alibaba Cloud in Beijing.

The server address is:

The public key can be retrieved by looking at the TXT DNS record:

dig TXT


The server uses Google’s Golang implementation.

Why China?

The Roughtime protocol works best when clients can query several independent servers. Ideally, the Roughtime ecosystem would have diversity in:

  • time source
  • cloud hosting providor
  • network connectivity
  • geographic location
  • political jurisdiction
  • proximity to nation-state actors seeking to manipulate the system

Running a server in mainland China, behind the Great Firewall, on the Alibaba cloud, should improve the diversity of the ecosystem.

Time Source

The server uses Chrony to synchronize the system clock with the Alibaba Cloud internal NTP servers. The internal servers are synced to an atomic reference via satellite. Alibaba would not reveal to me if they used GPS, BeiDou, or another constellation to synchronize the clocks. I take this to mean they use GPS.


This service has very basic monitoring in place. I don’t want to pay for a proper load-balancing solution, so the service is single-homed for now.


If you find this service useful, feel free to send me a note at [email protected].