Set #7 is much harder than #6. And there're rumors about set #8 which has attacks on EC-algos.

Set #6 is also much harder than set #5! Or at least, I thought so, but I haven't finished it or, sadly, worked on it for quite a few months.

We know what the 8 challenges are, but we have to do the work of getting good reproducible challenges worked out for them.