  Homomorphic encryption is a sophisticated encryption technique that allows
computations on encrypted data to be done without the requirement for
decryption. This trait makes homomorphic encryption appropriate for safe
computation in sensitive data scenarios, such as cloud computing, medical data
exchange, and financial transactions. The data is encrypted using a public key
in homomorphic encryption, and the calculation is conducted on the encrypted
data using an algorithm that retains the encryption. The computed result is
then decrypted with a private key to acquire the final output. This abstract
notion protects data while allowing complicated computations to be done on the
encrypted data, resulting in a secure and efficient approach to analysing
sensitive information. This article is intended to give a clear idea about the
various fully Homomorphic Encryption Schemes present in the literature and
analyse and compare the results of each of these schemes. Further, we also
provide applications and open-source tools of homomorphic encryption schemes.
