With the increase in traffic on cloud servers due to the shifting of various services, information security has become a matter of major concern. This paper describes the security issues influencing cloud computing, compares the performance of traditional and the latest security techniques, and focuses on the challenges facing its implementation. Traditional schemes like RSA, ElGamal, and Pailler Algorithms do not allow operations to be carried out on the encrypted data, whereas the Homomorphic Encryption Scheme allows computation in the encrypted state without decrypting it to the original form. Thus, the security is ensured and also, there is no need to share the secured key. Fully Homomorphic Encryption Algorithms like: Gentry’s Encryption Scheme, Dijk-Gentry-Halevi-Vaikunthanathan Scheme (DGHV), Brakerski-Vaikuntanathan Schemes (BGV) and Multi-key fully Homomorphic encryption are advanced techniques that provide security for the cloud are also described.

随着各种业务的转移，云服务器的流量不断增加，信息安全成为人们关注的焦点。本文描述了影响云计算的安全问题，比较了传统和最新安全技术的性能，并重点讨论了其实施所面临的挑战。RSA、ElGamal 和 Pailler 算法等传统方案不允许对加密数据进行操作，而同态加密方案允许在加密状态下进行计算，而无需将其解密为原始形式。因此，保证了安全性，并且无需共享安全密钥。完全同态加密算法，例如：Gentry 加密方案、Dijk-Gentry-Halevi-Vaikunthanathan 方案 (DGHV)、