Cloud computing is an on demand paradigm which provides a different kind of services to the cloud users. Cloud storage is the most popular service, as the data owners are free from the data management and storage overhead. However, the data owners’ concern about the security of the data. In order to address this issue, this paper presents an efficient security with an auditing scheme that guarantees the security of the data and preserve data integrity. In this paper, the cloud storage auditing model used efficient privacy preserving algorithm, namely Markle Hellman Knapsack Crypto-System (MHKCS) algorithm. This algorithm effectively improves the data integrity, confidentiality and security. Moreover, reduces the key generation time, encryption time and decryption time. The performance of MHKCS algorithm is calculated using evaluation metrics like encryption time, decryption time, key generation time and communication cost. The MHKCS algorithm achieved approximately 10% better performance in terms of encryption time than the existing methods RSA, MRSA, and MRSAC.