Network Time Security
What is NTS?
NTS is an essential development of the Network Time Protocol (NTP). It has been developed within the Internet Engineering Task Force (IETF) and adds a much needed layer of security to a protocol that is more than 30 years old and is vulnerable to certain types of attack.
NTS consists of two protocols, a key exchange and extended NTP. This ensures that clients can validate that the time that they receive has been sent from the correct server. More detailed information about how NTS works is available here.
How to use NTS
NTS is a free service available to anyone, anywhere in the world. The only thing you need is an NTS-enabled NTP client. For more information about how to set this up, see here.
Netnod’s NTS-enabled NTP service is freely available to anyone. You can point your NTS-enabled NTP client (using port 4443*) to one of the following servers:
- nts.ntp.se (for users anywhere in the world)
- nts.sth1.ntp.se (for users close to Stockholm)
- nts.sth2.ntp.se (for users close to Stockholm)
* Note that this port number, although it is an approved Proposed Standard, still can change.
What are the benefits of using NTS?
NTP is vulnerable to Man-in-the-Middle (MITM) attacks. This is where a malicious actor sits between you and the NTP server, listens in on the conversation, forges messages and lies to you about time.
With many of today’s most important security processes dependent on accurate time, the consequences of receiving time from a malicious source are serious. Everything from establishing encrypted sessions and using DNSSEC to time-stamping financial transactions and preventing online fraud depends on accurate and secure time. By using NTS, you can be sure your devices are receiving accurate time from a reliable source.