Secure Multi-Cloud Data Exchange Using Hybrid AES-256 and RSA-2048 Encryption

The growing use of multi-cloud architectures has led to large-scale challenges in securing data exchange on heterogeneous platforms. This paper introduces the Hybrid Multi-Cloud Secure Exchange (HMCSE) framework, which is designed to enable secure, efficient, and auditable data exchanges between Microsoft Azure and Amazon Web Services (AWS). The primary purpose of HMCSE is to provide end-to-end data confidentiality and data integrity through a three-layered security model based on AES-256 symmetric encryption for high-speed protection, RSA-2048 for secure key exchange, and generic PBKDF2-based key management protocol for manual and automated provisioning. The system also includes JWT-based stateless session management and full audit trails to enable regulatory compliance and real-time monitoring. Experimental results indicate that HMCSE offers an average encryption throughput of 100 MB/s and maintains encryption times below 100 milliseconds for average file sizes, much superior to existing multi-cloud security frameworks in speed and scalability. These results confirm that HMCSE offers a new benchmark for secure, extensible, and production-ready data exchange in dynamic multi-cloud environments without compromising operational agility and efficiency.