The shift towards a quantum-secured future has driven the demand for more practical ways of protecting files that can add post-quantum cryptographic components without creating a massive increase in computational or storage demands. This study proposes and tests a hybrid file-security approach combining a post-quantum key encapsulation mechanism and authenticated symmetric encryption for real-world file security. An experimental research design was followed with the use of a valid subset of GovDocs1 corpus as the evaluation sample, and the files were stratified based on the format, size and entropy characteristics. Three different architectures were designed, built and evaluated for design evolution from direct lattice-style architecture to standards-based hybrid architecture. Correctness, runtime, and ciphertext expansion were used to measure performance and compared to other files of various types and data characteristics. The results demonstrate the capability of the final framework to retain the exact reconstruction of the file and gain significantly in storage efficiency and execution time over previous model generations. A comparison of performance over different heterogeneous categories of files showed no significant difference, and overhead was seen to be a consistent decreasing function of file size. The results show that a hybrid design that can provide quantum resistant key protection and efficient authenticated encryption can be used to provide practical post-quantum-ready file security. The study offers an empirically supported framework for the security of files in a post-quantum era and offers a repeatable foundation for research into implementing it for deployment.