I am solving the following problem : I have edge-matching puzzles, where all pieces are squares and the grid has $n$*$n$ format. There is no global image to guide a puzzle solver. Despite the puzzles match locally, they have not to stay together also in the final solution. (it can be verified whether to edges of two pieces match in $\theta(1)$)
I should prove to Bob, without revealing any useful information to him, that I have solved the puzzles. I tried to apply the approaches based on well-known zero-knowledge problems like graph-coloring or Hamilton's path in graph but I think, I am still missing something. Do you have any hints please?