A networked hardware or software product engineered to meet the mandatory security requirements of the EU Cyber Resilience Act (CRA) before the December 2027 deadline. To be considered defensible: a product must feature a secure by design architecture that includes an authenticated transport layer for control data and management. Key components of a defensible product include a maintained Software Bill of Materials (SBOM): a documented risk assessment: and a verified process for reporting exploited vulnerabilities to ENISA within 24 hours. For manufacturers in the entertainment lighting sector: transitioning from unencrypted protocols to secure frameworks like Sig-Net is a critical step in creating a product that is legally defensible under EU law. QubiCast helps manufacturers reach this status through the QubiCore library: providing a secure stack that simplifies the documentation and technical requirements of the CRA.