Small and medium-sized enterprises (SMEs) face significant challenges from security breaches, which can jeopardize their operational sustainability. This study presents the BLOCKSAGE SME system, a model designed to enhance the security of sensitive data storage and transfer. The system integrates customizable cloud infrastructure, private blockchain networks, Zero Trust architecture, a scalable API, and IPFS encryption, ensuring data privacy and business continuity. Based on a comprehensive literature review of blockchain-based solutions for SMEs, a web-based file-sharing prototype was developed and tested to validate the framework. The system was then evaluated through expert judgment and feedback from SME leaders. The results showed a satisfaction score of 4.06 from cybersecurity and blockchain specialists and 4.2 from the target SME audience on a Likert scale, indicating the system’...