A Problem That Had to Be Solved

There was a difficult problem that had to be solved.

But it came with a severe constraint.

Even if the solution was found, the solution itself could not be touched.

That made it truly difficult.

In other words, it was a problem similar to a zero-knowledge proof.

You had to show that the problem had been solved
without revealing the details—without exposing any unnecessary information.

That was the nature of the challenge.

And the fact that it took this form…

That, in itself, is remarkable.