Algorithm 2 HE decryption algorithm for Scenarios 1 and 2.

1:Input $sk$: the secret key for the decryption 2:Input $ciphertexts$: the ciphertexts array 3:Input N: the number of the households 4:Input $decryptor$: the object that performs decryption 5:for $index=1,2,\dots ,N$ do 6:      $c^{\ast }\leftarrow ciphertexts\left[index\right]$ 7:      $data\leftarrow decrypt(c^{\ast },decryptor,sk)$ 8:      push $data$ into $plaintexts$ array 9:end for 10:Output $plaintexts$ array