Suppose that Alice received the cipher values: $E(x_1), E(x_2), ..., E(x_n)$ that are encrypted using Paillier cryptosystem by $n$ entities with Bob's public key.
Alice computes $E(\sum x_i)$ from the product of the cipher values she received. Alice sends $E(\sum x_i)$ to Bob for decryption, but she needs to prove that she used all the cipher values she received to form the product $E(\sum x_i)$ for Bob to return the plain text $\sum x_i$.
What should each entity: $i$ send along with their share $E(x_i)$ for Bob to be able to do such verification, and how could he do it?
Note: $x_i$ values are not merely $0$ or $1$. They can take any integer value.