The discrete logarithm is the simplest thing that the user has to understand to be able to solve this challenge. By "simple to understand what it is" I do not mean that it is also easy to compute it. I guess nobody here would have problems to understand what the discrete logarithm is.

The problem is in understanding the system. And apparently there is a system, otherwise the challenge would be called solve the discrete logarithm and in PDF there would be one equation a^x=b mod N with given (a,b,N).

RSA is also a pure math. But it is also a system, precisely many different systems based on the same math problem. So if you understand that math problem does not mean that you can automatically understand every system, because every system can have its own specifications that you must be aware of.

ECC is again about pure math. But also a system, precisely many different systems…

Discrete logarithm is again about pure math. But can be used in many different ways, i.e. in many different systems.

UOV is again about pure math. But also a system… bla bla… same as above…

Most of the modern cryptographic systems are about pure math. And the same math problem can be used in many different ways, i.e. in many different systems.

Now I said enough. I will not be expressing myself to this topic anymore. Of course unless the author contribute with something, or a person that understands the system precisely.