如何在Node.js中创建人类可读但机器不可读的文本？

Question

I am making a simple mental math training app at https://mattea.app/ . It is a timed competition, and I measure the time you spend answering 10 exercises.

The exercises are made on the server - in Node.js function served through Google Firebase Cloud Functions.

One problem is that users can cheat by making a script that read the exercises and then programmatically calculate and submit the answers really quick. To make this harder, I return the execise as an SVG-tag, but each number turns into the same output each time, so it is not so hard to crack.

How can the Node.js function return the exercise text (for instance "9x8") in format that is human readable but not so easily machine-readable?

Answer 1

I ended up converting the number to a SVG path. Later on I can add some randomness to the numbers in the path, so that it cannot easily be reversed. Of course this could be reversed by an OCR algorithm, but at least it makes it a bit more work to do.