Fully Homomorphic Encryption (FHE) represents a breakthrough in cryptography, allowing operations to be performed directly on encrypted data without decryption. This property holds immense potential for secure data processing in untrusted environments like cloud computing. This systematic review analyzes FHE schemes’ security weaknesses, identifies existing gaps, and evaluates their practical applications and limitations. The results reveal that significant challenges remain while FHE offers robust security services, such as data confidentiality and integrity. The main weaknesses are high computational costs, noise growth, and large sizes in ciphertexts, which limit the scalability of these implementations. Additionally, the lack of standardization in evaluation methodologies and limited validation in industrial environments hinders its adoption in real-world applications. Key areas for improvement were identified, including developing more efficient schemes and their practical validation. The findings provide a roadmap for researchers and professionals interested in optimizing FHE for future applications such as cloud computing, big data analytics, and electronic voting.