Notes on Two Fully Homomorphic Encryption Schemes Without Bootstrapping

Recently, IACR ePrint archive posted two fully homomorphic encryption schemes without bootstrapping. In this note, we show that these schemes are trivially insecure. Furthermore, we also show that the encryption schemes of Liu and Wang in CCS 2012 and the encryption scheme of Liu, Bertino, and Xun in ASIACCS 2014 are insecure either