XOT: On Privacy, Security, and...

Straks account vereist voor Philips Hue app?

Sun, 17 Sep 2023 00:00:00 +0000

Het lijkt er op dat mensen die de Philips Hue app gebruiken om hun slimme lampen te bedienen binnenkort verplicht worden een account aan te maken. Dat is tenminste wat deze melding in de app lijkt te suggereren.

Dat gaat toch echt een stap te ver.

End-to-end encryptie en risico’s client-side scanning

Sat, 26 Aug 2023 00:00:00 +0000

De Europese Commissie wil serieus werk maken van de bestrijding van online kindermisbruik. Vorig jaar diende de commissie hiervoor een wetsvoorstel in dat grote online dienstverleners verplicht noodzakelijke maatregelen te treffen. Middels deze blog wil ik aandacht vragen voor een aantal fundamentele bezwaren die aan het voorstel van de Commissie kleven.

Optimising Deft for Emacs

Tue, 01 Aug 2023 00:00:00 +0000

Deft is an Emacs mode for quickly browsing, filtering, and editing directories of plain text notes, inspired by Notational Velocity. I started using it more, but as the number of notes increased it became slower and slower. Here is how I managed to make it snappy again, also for older Emacsen. (Updated with more general code).

From Postbox back to Thunderbird

Sun, 23 Jul 2023 00:00:00 +0000

I am a long time email user. (Yes, I’ve even used Gnus to read my mail!) Seven years ago or so, when it looked like Thunderbird would no longer be maintained, I switched to Postbox to read my mail. I was happy with it, especially with its clear and modern UI and its support for tagging email. But now Postbox appears less well maintained: there are UI bugs, it has become slow and unresponsive, and updates are few. So I decided to return to Thunderbird, especially now that it properly supports a vertical, fully column based view that I liked in Postbox, using the new card view to summarise messages in the message list.

Yet another OV-chipcard usability fail.

Sat, 01 Jul 2023 00:00:00 +0000

It seems the Dutch OV-chipcard system was invented to showcase every possible way to make a system not user friendly. Here is the latest usability fail, involving payment cards, tickets with QR codes stored on mobile phones, and Apple/Google pay.

Provinciaal? Nederlands op de universiteit is juist inclusief!

Tue, 27 Jun 2023 00:00:00 +0000

Het is jammer dat ook Caroline de Gruyter provincialisme als argument gebruikt tegen het plan van minister Dijkgraaf om het Nederlands op de universiteit beter te beschermen. Zo wordt dit plan tot onderdeel van de ‘cultuuroorlog’ gemaakt, terwijl het plan eigenlijk juist heel inclusief en verbindend is. Laat me dat uitleggen.

A simulator for dynamic electricity contracts (with some surprising results)

Thu, 15 Jun 2023 00:00:00 +0000

We have solar panels for over a decade now, producing more than we consume, so our current fixed price energy contract is most cost effective. But as our electric camper van will (hopefully) soon arrive, I wondered whether it would make sense to switch to a dynamic contract where the price for electricity varies per hour. To figure that out, I wrote a small energy simulator, to compute the expected electricity cost while varying certain parameters. The results were at times surprising!

The Eternal Orchestra

Mon, 01 May 2023 00:00:00 +0000

Some years ago I thought of an personal readio station, generated by AI. This morning another variant of that idea popped up: the eternal orchestra. An AI trained on all music of a particular composer, generating new concerts forever as if they were freshly written by Bach (or Mozart, or Chopin, or Stockhausen, or Stravinsky, or…). A dedicated concert hall could be built for each of these orchestras. And robots could be programmed to play the music on real instruments. And people could come in day and night, to listen to their favourite composer. And could come back again and again, never hearing the same composition twice. Wouldn’t that be heaven?.

Real New Vintage

Sun, 30 Apr 2023 00:00:00 +0000

Ye gave me an idea. Or rather, an article in a Dutch newspaper about Kanye West and his fashion deals gave me an idea. It’s cruel. It’s mean. Hear me out.

A proposal for a privacy friendly digital euro, using the existing payment infrastructure

Fri, 03 Mar 2023 00:00:00 +0000

Some years ago I wrote about privacy-friendly ticketing for public transport. Today I want to show how similar techniques can also be used to implement a privacy-friendly contactless payment system. The idea is inspired by recent payment wallets and banking apps that allow users of smartphones to make contactless payments at point of sale terminals in physical shops. The system I describe here does exactly the same, but now in a privacy-friendly fashion: it prevents banks or shops to profile you based on your payments. The core is a special wallet app on a smartphone (to protect privacy), leveraging the existing payment infrastructure (to enable a smooth and gradual roll-out of the system). In particular I would propose this as a possible implementation of the ‘digital euro’.