Algorithm 5. Verify.

Input: $\mathcal{I},B$, $T{K}_{i,Q}$, ψ

Output: proof

1:   ${\psi }^{\mathrm{\prime }}\leftarrow \varphi ,proof=0$.

2:  Using search trapdoors $T{K}_{i,Q}$ to perform phrase searches same as line 1–line 6 of Algorithm 4.

3:  for ${\ell }_i\in I{D}_{\mathcal{B}}$ do

4:       $has{h_i}^{\mathrm{\prime }}\leftarrow B[{\ell }_i],{\psi }^{\mathrm{\prime }}\leftarrow {\mathcal{+}}_{\mathcal{H}}\mathcal{H}(r,has{h}_i)$

5:  end for

6:  if $\psi ={\psi }^{\mathrm{\prime }}$ then

7:       $proof=1$

8:  end if

9:  The blockchain sends proof to the data user.