<p>Currently, cloud computing has become one of the key tools in the field of information technology. Their popularity is due to their high flexibility and scalability, as well as cost-effectiveness. However, cloud computing also poses significant data security challenges. The main method to protect data in cloud computing is encryption, which, while ensuring data confidentiality, complicates data processing. Moreover, traditional encryption methods do not allow operations with encrypted data to be performed without decrypting them, which may be impractical or even impossible in the case of processing large amounts of data, which suggests the expediency of using fully homomorphic encryption schemes.In this paper, information security threats in the cloud infrastructure are identified, ways to prevent the described threats are analyzed, and it is proved that homomorphic encryption can comprehensively solve security problems in cloud environments. The architecture and algorithm of functioning of a software tool that ensures the security and confidentiality of data transmitted and processed in a cloud environment are described, quantitative characteristics of its performance are obtained, and advantages over existing solutions are shown.</p>