A secure and inexpensive method for sortition

Our association (l’APRES) organizes discussions every Sunday either on the internet, in real life, or both. Every Monday, a week in advance, we randomly pick someone to choose the next discussion’s theme. We thus needed a cheap and secure way to carry out this weekly selection. This post demonstrates how this is done.

The first step consists in going to this website. On this page, you need to enter a “seed” number to produce the output. As a seed we use the CAC 40 value at the market opening of that day – Monday. This value is publicly available and easy to determine and verify. Importantly, the same seed produces the same output (i.e., the same selected person) but at the same time two very close by seeds produce different, wholly unrelated, outputs (see why here).

In the demonstration shown in the following images, I employ a few names of people from this blog.

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