In the present scenario, the Cloud Computing is very famous and flexible technology. It facilitates customers with effortlessness, quickness, competence etc in their work area through the services. Cloud provides huge data centre to handle the large amount of information. The Cloud Computing benefits the organizations to handle their large volume of information. The main issue in cloud computing is data security, because number of customers are sharing same cloud. This study aimed at designing a new security method by using a hybrid cryptosystem, for data security in the cloud. The need for the current investigation is to protect data from unauthorized access or hackers in cloud at the time of data transmission by encrypting the user data. Cloud computing constitutes several security issues including data access control, identity management, auditing, integrity control and risk management therefore, this hybrid cryptosystem is designed and comprises of both symmetric and asymmetric cryptography algorithm in which Blowfish symmetric algorithm deals with data confidentiality whereas, RSA asymmetric algorithm deals with an authentication. This method also includes the Secure Hash Algorithm -2 for data integrity. The present study concluded that the proposed method provides high security on data transmission over the internet and proper network access on demand to a shared tank of constructive computing resources, mainly net, server, and storage application. © 2017 IEEE.