Modern operating systems incorporate numerous built-in security features designed to protect the data handled by locally running software applications. However, the advancement of data extraction tools and techniques has shown these features alone to be insufficient for ensuring reliable local data protection in highly secure software. Such software demands significantly stronger data security guarantees than those required for general-purpose applications. As software grows in complexity and security threats become more sophisticated, it is essential for highly secure software to implement a multi-layered security strategy. Despite the extensive body of knowledge on software security and widely accepted recommendations and guidelines, these are not always correctly implemented. The author’s previous work has provided a proof of concept showing how the security of specific highly secure software can be breached by a potential attacker. Based on this, and the author’s experience, this work proposes a comprehensive strategy for securing local data access in highly secure software by combining multiple security mechanisms in order to provide improved resilience against unauthorized data access, ensuring robust data security in environments demanding the highest levels of protection. Additionally, the paper presents an example reference implementation of the suggested strategy in specific highly secure software to validate its applicability.