The search for the random numbers that run our lives

BBC ^ | https://www.bbc.com/future/article/20240704-the-search-for-the-random-numbers-that-run-our-lives | Chris Baraniuk

[BenLurkin]

here are some things that computers, for all their prowess, don't do well – and one of them is randomness. Sure, computers spit out data all the time, why not random numbers? The problem is that computers rely on internal mechanisms that are at some level predictable, meaning the outputs of computer algorithms eventually become predictable, too, which is not what you want if you're running a casino. The same issue can cause headaches for cryptographers. When you encrypt information, you want the keys to the code to be as random as possible, so that no-one can work out how you garbled the original text since that could allow them to read the secret message.

People have long sought external sources of randomness as the basis of random number generators. In this search for true randomness, they have looked practically everywhere for chaotic phenomena that can't be predicted or manipulated. They have listened to the racket of electrical storms, captured pictures of raindrops on glass, and played with the tiniest particles in the known Universe.

Random numbers are essential for securing information, he points out, since they are used whenever a computer encrypts data so that it looks to any casual observer like mere gobbledegook. When you visit a website that begins "https://", for example, you're asking your computer and the server that stores the website to, among other things, generate some random numbers, exchange them and then use them to encrypt the data sent back and forth as you load the website and go on to use it. (This is an enormous simplification of the exchange that takes place in just a few milliseconds, but you get the drift.) When sensitive data is flying around computer networks, especially those accessible by the public, it's essential to secure that information.

[asinclair]

Then there are the "white noise generators" that use diodes to generate random sequences, at a fast clip. I've seen the analysis of such generators and, while not absolutely perfect, can be good enough for many applications, including Monte Carlo applications.

You get a marginal improvement when you use cosmic rays, or emissions from radioactive material.

[KarlInOhio]

I always use a nice cup of really hot tea as a Brownian motion producer to drive my Finite Improbability Generator. It's a great ice breaker at parties.