White Paper: How does NTS work and why is it important (Netnod)

The Network Time Protocol (NTP) is a venerable Internet protocol for synchronising time. It has been with us since at least 1985 as the most commonly used protocol for synchronising the time on computer systems. It enables devices connected to the Internet to maintain clock synchronisation with reliable time sources, such as the atomic clocks used to provide Netnod’s NTP service.

See: https://labs.ripe.net/Members/michael_cardell_widerkrantz/what-is-network-time-security-and-why-is-it-important