Abstract: Now a days, most of the companies are moving to the cloud environment, because of its major advantages such as flexibility, faster implementation and lower cost. Almost every cloud applications have two major challenges such as security and privacy. Today, most of the sensitive data are stored in a third party systems may cause severe security problem. According to third party cloud storage system, data confidentiality depends on key distribution center only. Our secure cloud storage system belongs to the decentralized architecture where storage server offers good scalability. Since many of the security algorithms are required key handling management and regeneration which creates greater overhead. It is proposed to introduce an efficient security algorithm such as a Cyclic Shift Transposition Algorithm (CSTA) for secure cloud storage system. It consists of the combination of shifting and transportation operations. This algorithm not only prevents from known attack but also maintain the integrity of the data. Here the onetime verification system and hash based timestamp technique are used to forward and retrieve the data in a secure manner. It builds the additional security wall over the data. The proposed model provides high data integrity and privacy so that only trusted user can get the data in an efficient manner.