Security-Bits.de

Most things that can easily kill you and others, require certification to ensure that applicable measures to reduce risks have been applied and that they’re functional. While all this is pretty trivial in the analog world, open a door -> release a switch -> open switch triggers a relay -> machine stops, the digital world is a little more complex. Especially when a program running on an operating system periodically scans an I/O port to check whether it has changed its state. Even when using interrupts things don’t get much easier. Here a few things to consider when looking into similar topics.

A while back I started looking for a solution with which I could prove to be able to work safely from home while breaking devices. Sadly, I wasn’t able to find anything small and cheap enough to actually fit my desk. The best options I found where actual workbenches and tables in various sizes. Thus I decided to design my own Electronics Working Environment.

Back when COVID had started and the first vaccinations had been applied, there was the fun challenge of proving one’s vaccination status. It ended up working based on a digital signature provided as QR Code on a piece of paper. Needing it every day, paper didn’t quite have the necessary durability, the digital versions only helped people with smart phones, so I created a plastic card alternative.

Possibly highly intuitive to others, but a real b**** when not being fit. Here an insight into how to configure a Site to Site VPN with OpenVPN and two OPNsense routers and multiple subnets on both sides.

In Germany petrol stations have to regularly share the price of their products with a government agency. In addition public APIs were created, which give close to realtime access to the prices. Here a little example on how to fetch and use the data.

A while back Germany decided it would be a good idea to regulate the IT infrastructure in doctor’s practices. While obviously a smart move, it resulted in strange interpretations and even stranger architectures being implemented. This post shows the actual setup. But, er ist auf deutsch (it’s in German).

I recently received a nanoBTS 165G, which strangely enough made a rattling sound. While it’s a bad sign, as there might be a chance to short out and break the BTS, it’s a super easy fix. Here the insights!

One of my big Todo List projects is temperature monitoring for the house. Being a big fan of wired approaches, many available solutions don’t match my requirements or are far to expensive. Luckily Olimex published the perfect plattform a while back. I finally managed to get one. Here are some insights.

A lot of time is invested into defining and describing OT Security or Operational Technology Security, especially in contrast to IT Security. It’s very often hard to draw a proper line between both and complicated to keep it strict. Here is a little insight into why the line helps, where it makes things worse and a few recommendations on dealing with the resulting challenges.

A while back Germany decided it would be a good idea to regulate the IT infrastructure in doctor’s practices. While obviously a smart move, it resulted in strange interpretations and even stranger architectures being implemented. This post shows a secure reference architecture with explanations. But, er ist auf deutsch (it’s in German).