. 2024 Nov 22;10:e2235. doi: 10.7717/peerj-cs.2235

Algorithm 3. TokenGen.

Input: The query phrase

\tilde{w}

, the key set K

Output: The serach trapdoor

T K_{i, Q}

1: Suppose that query phrase

\tilde{w} = {w_{1}, w_{2}, . . ., w_{t}}

2: for

j = 1 \to t

s t_{j} \leftarrow \sum [w_{j}], u_{w_{j}} \leftarrow F_{1} (K_{3}, w_{j})

t_{w_{j}} \leftarrow H_{2} (u_{w_{j}} | | s t_{j})

5: if

j > 1

then

d = j - 1; E_{d} \leftarrow P a i l l i e r . E n c (d)

7: end if

8: end for

9: send

T K_{i, Q} = {t_{w_{1}}, t_{w_{2}}, . . ., t_{w_{t}}, E_{1}, E_{2}, . . ., E_{t - 1}}

to blockchain and cloud server