Output Assignment Uses <-- Without Constraints, Allowing Malicious Proof Generation

[Koukyosyumei]

In zkPhoto.circom, the output is assigned using the <-- operator, which does not enforce any constraints. As a result, a malicious prover can generate a fake proof with incorrect outputs, compromising the integrity of the circuit.

zkPhoto/circuits/zkPhoto.circom

Line 41 in 12b8d51

out[idx] <--

Without explicit constraints enforcing the expected behavior of the shift operation, the circuit becomes vulnerable to manipulation. A prover could arbitrarily choose an output without satisfying any underlying computation.

To properly implement the shift operation with sufficient constraints, consider referencing established implementations for similar functionalities, such as:

• circom-monolith.

Would appreciate any thoughts or confirmation on this fix!