We implement the extension_factor default as 16 and the sampling inspection default time as 16, so the security level will be 80 bits. Polynomial commitment: we calculate the hash value of the computation trace and corresponding user balance, user ID, and the value of the corresponding constraint polynomial for each row, and generate a Merkle tree. The Merkle root is the commitment value of the polynomial. Generating sampling proof: using the Merkle root as a random source, we sample the data.