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Technical, Page 5

Raspberry PI Pool controller upgrade

My Raspberry PI-based pool controller has been running our pool pumps faithfully for the past 18 months. Every morning, it switches the two pumps on (first one, then the other), and runs them for a few hours (switching them off in reverse sequence). It is really nice to sit out on the deck, go to…

Is there anything about identity on the internet that’s not broken?

We know that usernames and passwords are broken, password resets are, SSL certificates, hacks like certificate pinning etc. and many other things. Apparently even domain name ownership proof is just as broken: there seems to be no method to authoritatively determine whether somebody who claims to own a domain actually does. If somebody came to…

Digital signatures on JSON payloads — let’s call it ‘jsonsig’

I'm finding myself wanting to digitally sign JSON content, keeping the signature and metadata inside the JSON file, and I'm largely coming up empty looking for a solution that exists already. I only found: Camlistore: it signs JSON documents but creates an "outer wrapper". It's also a bit too specific to Camlistore for my needs.…

Making relationships verifiable

(This is more of a note to myself, but you might find it interesting anyway) Let's say there are two people, M and D, who supposedly are mother and daughter, i.e. they are supposedly in the relationship "is parent of". If I come across a piece of information that expresses "M.isParentOf.D", should I believe it?…

Power Consumption of Various Little Computers

Today's fun facts: Device Approx. power consumption Raspberry PI 2-3W BeagleBone Black 1-2W Wandboard Quad 2-4W Wansview Webcam 2-5W Netgear 5-port gigabit switch 4-5W Indie Box Prototype based on Atom with two drives 22W i3-based Home Server with four drives 70-80W Don't take those measurements too literally. I did not systematically try to distinguish between…