\begin{aligned}
& Alice: v_0, v_1, s, r_0, r_1 \\
& Bob: i \in \{0,1\}, k \\
& Bob \text{ want to get } v_i \\
& \text{Generate } g \in Z_p, g \text{ is large integer}, p \text{ is large prime number}\\\\
1. & Alice \to Bob : g_s \\
2. & Bob \text{ calculate } L_i = \begin{cases} g^k & \text{if }i=0 \\ g^{s-k} & \text{if } i = 1 \end{cases} \\
3. & Bob \to Alice :L_i \\
4. & Alice \text{ calculate } C_0 = (g^{r_0},(L_i)^{r_0}\oplus v_0), C_1=(g^{r_1},(g^s/L_i)^{r_1}\oplus v_1) \\
5. & Alice \to Bob C_0, C_1 \\
6. & Bob \text{ get } v_i = \begin{cases}
C_0[0]^k \oplus C_0[1] = (g^{r_0})^k \oplus (L_i)^{r_0} \oplus v_0 = (g^{r_0})^k \oplus (g^k)^{r_0} \oplus v0 & \text{if }i=0 \\
C_1[0]^k \oplus C_1[1] = (g^{r1})^k \oplus (g^s/L_i)^{r_1} \oplus v_1 = (g^{r_1})^k \oplus (g^k)^{r_1} \oplus v_1 & \text{if } i = 1 \end{cases}
\end{aligned}