Potential Bug in `SELECT` circuit

[Koukyosyumei]

In select.circom, line 79 uses an assert statement to check whether field[j] is binary. However, in Circom, assert does not generate a constraint—it only checks the condition during the witness generation, which is insufficient for enforcing validity within the circuit being proven.

zk-SQL/circuits/select.circom

Line 79 in 4c3626d

assert(fields[j] >= 0 && fields[j] <= 1);

To properly constrain the signal to be binary, this line should be replaced with:

(field[j] - 1) * field[j] === 0

[Koukyosyumei]

@nulltea Let me know if we need additional information!!