Blogposts
Decentralized Identifiers (DIDs) provide a way for entities to convey self-managed cryptographic material for identity assertion, and metadata. Entities can be anything, from persons, IoT devices, governance bodies, legal corporations to websites. DIDs are most commonly used when issuing or presenting Verifiable Credentials, and can be used as a more flexible and safe alternative to JWK Sets served on a URL.
I always liked outdoor activities and as such worried about degradation of the environment and climate change. But I never actively tried to do something about it, which changed after becoming a father. I worry about the world I’m leaving for my children and after reading more on the topic (I can recommend Bill Gates’ How to avoid a Climate Disaster), I too am convinced immediate action is required to keep our planet livable.
The internet has a big privacy problem: you don’t control your data, and laws or alone aren’t going to fix it, and here’s why:
I’ve always wondered about the magic which powers peer-to-peer file sharing. How you were able to quickly download some data by downloading small parts of it from many connected peers was something I didn’t quite understand. Now, many years later I’m using the same principles while working on a peer-to-peer network for Nuts, a disruptive decentralized information exchange network for health care providers. It was quite the Aha-erlebnis.
In Java 13 there’s an experimental feature called switch expressions introduced by JEP-354. It basically allows you to write a switch block as if it were an expression:
Cryptography has always been one of the harder programming subjects. It’s hard (but important) to get right, mathematically complex and we (luckily) don’t need to implement it ourselves very often. 99% of the time battle tested implementations will do, but sometimes you just have to roll your own. Or in my case, just have an irresistible urge to do so.
Parkinson’s Law tells us that “work expands so as to fill the time available for its completion”. Tim Ferriss explains this in his book The 4-Hour Workweek: when there’s too much time planned for a certain task or there’s no deadline at all, people focus on trivialities (and are thus wasting resources). To prevent this Tim suggests planning an unrealistically tight deadline, which forces you to focus on the bare essentials.
We built our home automation using OpenHAB on a Raspberry Pi 3. It has an awesome web interface, but it’s missing a SSL server certificate for added security. I could just use something off-the-shelve but since I want to try Quarkus and GraalVM I’ll be implementing my own Certificate Authority (CA). Just for the fun of it.