+-----+------+-----+
| a0 | a1 | a2 |
+-----+------+-----+
| a3 | a4 | a5 |
+-----+------+-----+
| a6 | a7 | a8 |
+-----+------+-----+
This is a Magic Square, where every row, column and diagonal should add up to a fixed {sum}, a predetermined unsigned integer.
Upon finding the solution, a valid zero-knowledge proof will be generated. The validity of the solution can be verified without revealing the solution itself.
The verifier can be exported as a Solidity contract, which allows for on-chain verification (i.e., a cryptocurrency bounty for puzzle solvers).