Cloud computing is a model for providing online services. These services can be accessed on a pay-per-use basis from anywhere at any time. However, data security in the cloud has become a very big problem. A major concern about data security is the cloud service provider (CSP), which has access to data, which in turn increases user concerns and reduces cloud capacity in many areas such as medical record databases and financial data. The problem of data security mainly affects the use of cloud computing by users and organizations. The current research on data protection has been done in multi-cloud computing so that CSPs do not have direct access to the data. In this paper, a secure and efficient cloud data system is proposed in order to ensure data confidentiality and integrity by encrypting the image using DNA encoding combined with the logistical map and spatial map. The encrypted image is then divided into chunks before being stored in the multi-cloud to ensure the confidentiality of the data. The hash value is calculated using the Message Digest (MD5) algorithm to verify the integrity of the data. The proposed system also supports efficient updating of outsourced data. For the security analysis, many experiments were conducted to ensure the confidentiality and privacy of data in a multi-cloud environment, where files of different sizes were used, and the analysis showed that the proposed system is more secure. On the other hand, conducted several tests to analyse performance with dynamic data support and latency, where the analysis showed that the results are at the required level. Finally, through a comprehensive analysis of security and performance, the proposed system is proven to be more secure in a multi-cloud environment and that the system is highly efficient