Category: How-to

  • chrony NTS certificate reload

    chrony NTS certificate reload

    The chrony NTS daemon has no way to automatically reload its NTS certificate. A quick hack fixes this.

  • Data lifecycle questions, not only for Blockchains

    Data lifecycle questions, not only for Blockchains

    In any data-centric applications, understanding the data lifecycle (also as part of the product lifecycle) is important, especially when trust or traceability are also goals. If Blockchain should play a role, then the requirements associated with the data lifecycle can even become a decisive factor: Either adapt the data model or the processes, or, if […]

  • Network Time Security: NTS articles overview

    Network Time Security: NTS articles overview

    NTP, the Network Time Protocol, is the way most computers and mobile devices obtain their time through. NTS (Network Time Security) is to NTP what HTTPS is to HTTP. It also is as easy to upgrade as upgrading to HTTPS is these days: No effort for the client, just adding a certificate for the server. […]

  • Debugging NTS problems

    Debugging NTS problems

    Debugging is hard, debugging security protocols doubly so. And there are not many tools and how-to’s availabe for NTS yet. So, here’s a (short) list of NTS problems I have seen and some tricks for debugging them.

  • NTS and dynamic IP addresses

    NTS and dynamic IP addresses

    Good news is that NTS relies on DNS names, no longer “naked” IP addresses. But what happens when the DNS name changes, pointing to a different IP address? A look at the protocol, the Chrony source, and the implications.

  • Configuring an NTS-capable NTP server

    Configuring an NTS-capable NTP server

    The choice of Network Time Protocol (NTP) servers supporting NTS is still very limited. Here is some advice to get it to run smooth and trustworty.

  • Transparent, Trustworthy Time with NTP and NTS

    Transparent, Trustworthy Time with NTP and NTS

    «Time is Money», as the old adage says. Who controls the time, controls all kinds of operations and businesses around the world. And therefore, controls the world. Today, we all take accurate time for granted. Even though, today, it is delivered over the Internet mostly unsecured. But this is easy to change.

  • Generating Multi-Architecture Docker Images Made Easy

    Generating Multi-Architecture Docker Images Made Easy

    Docker is cool and portable, but distributing Dockerfiles comes at a disadvantage: The demands on the build environment are high. Distributing Docker images solves this, but building them for an architecture other than your CPU architecture seems complicated. Here is a simple solution.

  • A SIP library is born

    A SIP library is born

    Inspired by Andrijan Möcker’s “Überallklingel” (Everywhere Bell), I decided to create my own. However, I wanted to use it with a motion sensor and therefore to be able to turn it off and on again, when necessary. I also felt that using Asterisk was overkill and it could be done quickly and much easier with […]

  • Telephony of Everything: From IoT to ToE

    Telephony of Everything: From IoT to ToE

    We all know about the Internet of Things. Cool or useless gadgets, which are each controlled by their individual app on our smartphone. This is often very convenient, but not always.